TY  - CHAP
AU  - Vemić, Ana
AU  - Kalinić, Marko
AU  - Čolović, Jelena
AU  - Erić, Slavica
AU  - Malenović, Anđelija
PY  - 2018
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3235
PB  - CRC Press-Taylor and Francis Group
T2  - Advances in Chromatography, Vol 54
T1  - Recent Progress in Fundamental Understanding and Practice of Chaotropic Chromatography Rationalizing the Effects of Analytes' Structure with Pharmaceutical Applications
VL  - 54
SP  - 1
EP  - 41
UR  - https://hdl.handle.net/21.15107/rcub_farfar_3235
ER  - 

@inbook{
author = "Vemić, Ana and Kalinić, Marko and Čolović, Jelena and Erić, Slavica and Malenović, Anđelija",
year = "2018",
publisher = "CRC Press-Taylor and Francis Group",
journal = "Advances in Chromatography, Vol 54",
booktitle = "Recent Progress in Fundamental Understanding and Practice of Chaotropic Chromatography Rationalizing the Effects of Analytes' Structure with Pharmaceutical Applications",
volume = "54",
pages = "1-41",
url = "https://hdl.handle.net/21.15107/rcub_farfar_3235"
}

Vemić, A., Kalinić, M., Čolović, J., Erić, S.,& Malenović, A.. (2018). Recent Progress in Fundamental Understanding and Practice of Chaotropic Chromatography Rationalizing the Effects of Analytes' Structure with Pharmaceutical Applications. in Advances in Chromatography, Vol 54
CRC Press-Taylor and Francis Group., 54, 1-41.
https://hdl.handle.net/21.15107/rcub_farfar_3235

Vemić A, Kalinić M, Čolović J, Erić S, Malenović A. Recent Progress in Fundamental Understanding and Practice of Chaotropic Chromatography Rationalizing the Effects of Analytes' Structure with Pharmaceutical Applications. in Advances in Chromatography, Vol 54. 2018;54:1-41.
https://hdl.handle.net/21.15107/rcub_farfar_3235 .

Vemić, Ana, Kalinić, Marko, Čolović, Jelena, Erić, Slavica, Malenović, Anđelija, "Recent Progress in Fundamental Understanding and Practice of Chaotropic Chromatography Rationalizing the Effects of Analytes' Structure with Pharmaceutical Applications" in Advances in Chromatography, Vol 54, 54 (2018):1-41,
https://hdl.handle.net/21.15107/rcub_farfar_3235 .

TY  - JOUR
AU  - Colović, Jelena
AU  - Kalinić, Marko
AU  - Vemić, Ana
AU  - Erić, Slavica
AU  - Malenović, Anđelija
PY  - 2017
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2807
AB  - In this study, we present novel insights into the pH-dependent retention behavior of protonated basic solutes in chaotropic chromatography. To this end, two sets of experiments were performed to distinguish between mobile phase pH and ionic strength effects. In the first set, the ionic strength (I) was varied with the concentration of NaPF6 and additives that adjusted the mobile phase pH, while in the second set, I was kept constant by adding the appropriate amount of NaCl. In each set, the retention behavior of 13 analytes was qualitatively examined in 21 chromatographic systems, which were defined by the NaPF6 concentration in their aqueous phases (1-50 mM) and the pH of their mobile phases (2,3 or 4); the acetonitrile content was fixed at 40%. The addition of NaCl significantly reduced the differences among retention factors at studied pH values due to the effect of the Na+ ions on PF6- adsorption to the stationary phase and the magnitude of the consequential development of the surface potential. A quantitative description of the observed phenomenon was obtained by an extended thermodynamic approach. The contribution of ion-pair formation in the stationary phase to the retention of the solutes was confirmed across models at the studied pH values in the set with varying I In the systems with a constant I, the shielding effect of the Na+ ions on the surface charge lowered the attractive surface potential and diminished the aforementioned interactions and hence the effect of the mobile phase pH on analyte retention. Eventually, we developed a readily interpretable empirical retention model that simultaneously takes into account analyte molecular structures and the most relevant chromatographic factors. Its coefficients have clear physical meaning, and owing to its good predictive capabilities, the model could be successfully used to clarify the contributions of analyte molecular structures and chromatographic factors to the specific processes underlying separation in chaotropic chromatography.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Influence of the mobile phase and molecular structure parameters on the retention behavior of protonated basic solutes in chaotropic chromatography
VL  - 1511
SP  - 68
EP  - 76
DO  - 10.1016/j.chroma.2017.06.069
ER  - 

@article{
author = "Colović, Jelena and Kalinić, Marko and Vemić, Ana and Erić, Slavica and Malenović, Anđelija",
year = "2017",
abstract = "In this study, we present novel insights into the pH-dependent retention behavior of protonated basic solutes in chaotropic chromatography. To this end, two sets of experiments were performed to distinguish between mobile phase pH and ionic strength effects. In the first set, the ionic strength (I) was varied with the concentration of NaPF6 and additives that adjusted the mobile phase pH, while in the second set, I was kept constant by adding the appropriate amount of NaCl. In each set, the retention behavior of 13 analytes was qualitatively examined in 21 chromatographic systems, which were defined by the NaPF6 concentration in their aqueous phases (1-50 mM) and the pH of their mobile phases (2,3 or 4); the acetonitrile content was fixed at 40%. The addition of NaCl significantly reduced the differences among retention factors at studied pH values due to the effect of the Na+ ions on PF6- adsorption to the stationary phase and the magnitude of the consequential development of the surface potential. A quantitative description of the observed phenomenon was obtained by an extended thermodynamic approach. The contribution of ion-pair formation in the stationary phase to the retention of the solutes was confirmed across models at the studied pH values in the set with varying I In the systems with a constant I, the shielding effect of the Na+ ions on the surface charge lowered the attractive surface potential and diminished the aforementioned interactions and hence the effect of the mobile phase pH on analyte retention. Eventually, we developed a readily interpretable empirical retention model that simultaneously takes into account analyte molecular structures and the most relevant chromatographic factors. Its coefficients have clear physical meaning, and owing to its good predictive capabilities, the model could be successfully used to clarify the contributions of analyte molecular structures and chromatographic factors to the specific processes underlying separation in chaotropic chromatography.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Influence of the mobile phase and molecular structure parameters on the retention behavior of protonated basic solutes in chaotropic chromatography",
volume = "1511",
pages = "68-76",
doi = "10.1016/j.chroma.2017.06.069"
}

Colović, J., Kalinić, M., Vemić, A., Erić, S.,& Malenović, A.. (2017). Influence of the mobile phase and molecular structure parameters on the retention behavior of protonated basic solutes in chaotropic chromatography. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1511, 68-76.
https://doi.org/10.1016/j.chroma.2017.06.069

Colović J, Kalinić M, Vemić A, Erić S, Malenović A. Influence of the mobile phase and molecular structure parameters on the retention behavior of protonated basic solutes in chaotropic chromatography. in Journal of Chromatography A. 2017;1511:68-76.
doi:10.1016/j.chroma.2017.06.069 .

Colović, Jelena, Kalinić, Marko, Vemić, Ana, Erić, Slavica, Malenović, Anđelija, "Influence of the mobile phase and molecular structure parameters on the retention behavior of protonated basic solutes in chaotropic chromatography" in Journal of Chromatography A, 1511 (2017):68-76,
https://doi.org/10.1016/j.chroma.2017.06.069 . .

TY  - JOUR
AU  - Milošević, Nenad
AU  - Vemić, Ana
AU  - Colović, Jelena
AU  - Kostić, Nada
AU  - Malenović, Anđelija
PY  - 2017
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3004
AB  - The quality by design approach has been applied to develop a chaotropic chromatography method for determination of trimetazidine dihydrochloride (TMZ) and two impurities (Y-145, Y-234). Baseline separation and accurate determination of the investigated analytes was set as the target analytical profile, with k (Y-145), k (TMZ), and alpha (Y-145/TMZ) selected as critical quality attributes. The critical process parameters studied in this research were pH of water phase, acetonitrile content in mobile phase, and concentration of perchloric acid in water phase. To compute a design space as a region of the knowledge space having satisfactory values of all critical quality attributes at the desired quality level, Monte Carlo simulations were performed to propagate the error originating from the calculated model coefficients to the predicted responses. At each of 4851 defined grid points, 5000 iterations were performed and the region having probability pi ae lt yen> 95% of achieving all defined critical quality attributes was computed. A working point situated in the center of the design space was chosen, corresponding to 27% acetonitrile in mobile phase, 63% 170 mM perchloric acid in water phase, and pH of water phase adjusted to 3.60. The method was validated to confirm its reliability for use in routine pharmaceutical analysis.
PB  - Springer Heidelberg, Heidelberg
T2  - Chromatographia
T1  - Design of Experiments-Design Space Approach for Development of Chaotropic Chromatography Method for Determination of Trimetazidine Dihydrochloride and Two Impurities
VL  - 80
IS  - 4
SP  - 585
EP  - 592
DO  - 10.1007/s10337-017-3275-5
ER  - 

@article{
author = "Milošević, Nenad and Vemić, Ana and Colović, Jelena and Kostić, Nada and Malenović, Anđelija",
year = "2017",
abstract = "The quality by design approach has been applied to develop a chaotropic chromatography method for determination of trimetazidine dihydrochloride (TMZ) and two impurities (Y-145, Y-234). Baseline separation and accurate determination of the investigated analytes was set as the target analytical profile, with k (Y-145), k (TMZ), and alpha (Y-145/TMZ) selected as critical quality attributes. The critical process parameters studied in this research were pH of water phase, acetonitrile content in mobile phase, and concentration of perchloric acid in water phase. To compute a design space as a region of the knowledge space having satisfactory values of all critical quality attributes at the desired quality level, Monte Carlo simulations were performed to propagate the error originating from the calculated model coefficients to the predicted responses. At each of 4851 defined grid points, 5000 iterations were performed and the region having probability pi ae lt yen> 95% of achieving all defined critical quality attributes was computed. A working point situated in the center of the design space was chosen, corresponding to 27% acetonitrile in mobile phase, 63% 170 mM perchloric acid in water phase, and pH of water phase adjusted to 3.60. The method was validated to confirm its reliability for use in routine pharmaceutical analysis.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Chromatographia",
title = "Design of Experiments-Design Space Approach for Development of Chaotropic Chromatography Method for Determination of Trimetazidine Dihydrochloride and Two Impurities",
volume = "80",
number = "4",
pages = "585-592",
doi = "10.1007/s10337-017-3275-5"
}

Milošević, N., Vemić, A., Colović, J., Kostić, N.,& Malenović, A.. (2017). Design of Experiments-Design Space Approach for Development of Chaotropic Chromatography Method for Determination of Trimetazidine Dihydrochloride and Two Impurities. in Chromatographia
Springer Heidelberg, Heidelberg., 80(4), 585-592.
https://doi.org/10.1007/s10337-017-3275-5

Milošević N, Vemić A, Colović J, Kostić N, Malenović A. Design of Experiments-Design Space Approach for Development of Chaotropic Chromatography Method for Determination of Trimetazidine Dihydrochloride and Two Impurities. in Chromatographia. 2017;80(4):585-592.
doi:10.1007/s10337-017-3275-5 .

Milošević, Nenad, Vemić, Ana, Colović, Jelena, Kostić, Nada, Malenović, Anđelija, "Design of Experiments-Design Space Approach for Development of Chaotropic Chromatography Method for Determination of Trimetazidine Dihydrochloride and Two Impurities" in Chromatographia, 80, no. 4 (2017):585-592,
https://doi.org/10.1007/s10337-017-3275-5 . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Kalinić, Marko
AU  - Erić, Slavica
AU  - Malenović, Anđelija
AU  - Medenica, Mirjana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2383
AB  - The aim of this study was to examine the interaction of the chaotropic salts of different position in Hofmeister series (CF3COONa, NaClO4, NaPF6) added to the mobile phase with the stationary phases of different hydrophobicity (C8 and C18 XTerra (R) columns), as well as their common influence on the retention behavior of pramipexole and its structurally related impurities. The extended thermodynamic approach enabled the understanding of the underlying separation mechanism. Comparing six different column-salt systems it was observed that general system hydrophobicity presented by salt chaotropicity and column hydrophobicity favors stationary phase ion-pairing over the ion-pair formation in the eluent. Further, an attempt was made to describe the influence of analytes' nature on their retention behavior in such chromatographic systems. An analysis is performed in order to select and elucidate the molecular descriptors (electrostatical, quantum-chemical, geometrical, topological, and constitutional) that best explain the experimental evidence and findings obtained by the thermodynamic approach. The results of this analysis suggest that analytes' charge distribution and its complementarity to the structure of the electric double layer formed on the surface of the stationary phase upon the addition of chaotropic additives can be useful for understanding the differences in retention of structurally related analytes. These findings provide a novel understanding of the interactions between all the components of the chromatographic system containing chaotropic additive and a good basis for further investigations suggesting the development of generally applicable predictors in structure-retention relationship studies in related chromatographic systems.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities
VL  - 1386
SP  - 39
EP  - 46
DO  - 10.1016/j.chroma.2015.01.078
ER  - 

@article{
author = "Vemić, Ana and Kalinić, Marko and Erić, Slavica and Malenović, Anđelija and Medenica, Mirjana",
year = "2015",
abstract = "The aim of this study was to examine the interaction of the chaotropic salts of different position in Hofmeister series (CF3COONa, NaClO4, NaPF6) added to the mobile phase with the stationary phases of different hydrophobicity (C8 and C18 XTerra (R) columns), as well as their common influence on the retention behavior of pramipexole and its structurally related impurities. The extended thermodynamic approach enabled the understanding of the underlying separation mechanism. Comparing six different column-salt systems it was observed that general system hydrophobicity presented by salt chaotropicity and column hydrophobicity favors stationary phase ion-pairing over the ion-pair formation in the eluent. Further, an attempt was made to describe the influence of analytes' nature on their retention behavior in such chromatographic systems. An analysis is performed in order to select and elucidate the molecular descriptors (electrostatical, quantum-chemical, geometrical, topological, and constitutional) that best explain the experimental evidence and findings obtained by the thermodynamic approach. The results of this analysis suggest that analytes' charge distribution and its complementarity to the structure of the electric double layer formed on the surface of the stationary phase upon the addition of chaotropic additives can be useful for understanding the differences in retention of structurally related analytes. These findings provide a novel understanding of the interactions between all the components of the chromatographic system containing chaotropic additive and a good basis for further investigations suggesting the development of generally applicable predictors in structure-retention relationship studies in related chromatographic systems.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities",
volume = "1386",
pages = "39-46",
doi = "10.1016/j.chroma.2015.01.078"
}

Vemić, A., Kalinić, M., Erić, S., Malenović, A.,& Medenica, M.. (2015). The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1386, 39-46.
https://doi.org/10.1016/j.chroma.2015.01.078

Vemić A, Kalinić M, Erić S, Malenović A, Medenica M. The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities. in Journal of Chromatography A. 2015;1386:39-46.
doi:10.1016/j.chroma.2015.01.078 .

Vemić, Ana, Kalinić, Marko, Erić, Slavica, Malenović, Anđelija, Medenica, Mirjana, "The influence of salt chaotropicity, column hydrophobicity and analytes' molecular properties on the retention of pramipexole and its impurities" in Journal of Chromatography A, 1386 (2015):39-46,
https://doi.org/10.1016/j.chroma.2015.01.078 . .

TY  - JOUR
AU  - Colović, Jelena
AU  - Kalinić, Marko
AU  - Vemić, Ana
AU  - Erić, Slavica
AU  - Malenović, Anđelija
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2365
AB  - The aim of this study was to systematically investigate the phenomena affecting the retention behavior of structurally diverse basic drugs in ion-interaction chromatographic systems with chaotropic additives. To this end, the influence of three factors was studied: pH value of the aqueous phase, concentration of sodium hexafluorophosphate, and content of acetonitrile in the mobile phase. Mobile phase pH was found to affect the thermodynamic equilibria in the studied system beyond its effects on the analytes' ionization state. Specifically, increasing pH from 2 to 4 led to longer retention times, even with analytes which remain completely protonated. An explanation for this phenomenon was sought by studying the adsorption behavior of acetonitrile and chaotropic additive onto stationary phase. It was shown that the magnitude of the developed surface potential, which significantly affects retention - increases with pH, and that this can be attributed to the larger surface excess of acetonitrile. To study how analytes' structural properties influence their retention, quantitative structure-retention modeling was performed next. A support vector machine regression model was developed, relating mobile phase constituents and structural descriptors with retention data. While the ETA_EtaP_B_RC and XlogP can be considered as molecular descriptors which describe factors affecting retention in any RP-HPLC system, TDB9p and RDF45p are molecular descriptors which account for spatial arrangement of polarizable atoms and they can clearly relate to analytes' behavior on the stationary phase surface, where the electrostatic potential develops. Complementarity of analytes' structure with that of the electric double layer can be seen as a key factor influencing their retention behavior. Structural diversity of analytes and good predictive capabilities over a range of experimental conditions make the established model a useful tool in predicting retention behavior in the studied chromatographic system.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties
VL  - 1425
SP  - 150
EP  - 157
DO  - 10.1016/j.chroma.2015.11.027
ER  - 

@article{
author = "Colović, Jelena and Kalinić, Marko and Vemić, Ana and Erić, Slavica and Malenović, Anđelija",
year = "2015",
abstract = "The aim of this study was to systematically investigate the phenomena affecting the retention behavior of structurally diverse basic drugs in ion-interaction chromatographic systems with chaotropic additives. To this end, the influence of three factors was studied: pH value of the aqueous phase, concentration of sodium hexafluorophosphate, and content of acetonitrile in the mobile phase. Mobile phase pH was found to affect the thermodynamic equilibria in the studied system beyond its effects on the analytes' ionization state. Specifically, increasing pH from 2 to 4 led to longer retention times, even with analytes which remain completely protonated. An explanation for this phenomenon was sought by studying the adsorption behavior of acetonitrile and chaotropic additive onto stationary phase. It was shown that the magnitude of the developed surface potential, which significantly affects retention - increases with pH, and that this can be attributed to the larger surface excess of acetonitrile. To study how analytes' structural properties influence their retention, quantitative structure-retention modeling was performed next. A support vector machine regression model was developed, relating mobile phase constituents and structural descriptors with retention data. While the ETA_EtaP_B_RC and XlogP can be considered as molecular descriptors which describe factors affecting retention in any RP-HPLC system, TDB9p and RDF45p are molecular descriptors which account for spatial arrangement of polarizable atoms and they can clearly relate to analytes' behavior on the stationary phase surface, where the electrostatic potential develops. Complementarity of analytes' structure with that of the electric double layer can be seen as a key factor influencing their retention behavior. Structural diversity of analytes and good predictive capabilities over a range of experimental conditions make the established model a useful tool in predicting retention behavior in the studied chromatographic system.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties",
volume = "1425",
pages = "150-157",
doi = "10.1016/j.chroma.2015.11.027"
}

Colović, J., Kalinić, M., Vemić, A., Erić, S.,& Malenović, A.. (2015). Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1425, 150-157.
https://doi.org/10.1016/j.chroma.2015.11.027

Colović J, Kalinić M, Vemić A, Erić S, Malenović A. Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties. in Journal of Chromatography A. 2015;1425:150-157.
doi:10.1016/j.chroma.2015.11.027 .

Colović, Jelena, Kalinić, Marko, Vemić, Ana, Erić, Slavica, Malenović, Anđelija, "Investigation into the phenomena affecting the retention behavior of basic analytes in chaotropic chromatography: Joint effects of the most relevant chromatographic factors and analytes' molecular properties" in Journal of Chromatography A, 1425 (2015):150-157,
https://doi.org/10.1016/j.chroma.2015.11.027 . .

TY  - JOUR
AU  - Pantović, Jasmina
AU  - Malenović, Anđelija
AU  - Vemić, Ana
AU  - Kostić, Nada
AU  - Medenica, Mirjana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2454
AB  - In this paper, the development of reversed-phase liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality by design (QbD) approach is presented. The defined analytical target profile (ATP) was the efficient baseline separation and the accurate determination of the investigated analytes. The selected critical quality attributes (CQAs) were the separation criterions between the critical peak pairs because the mixture complexity imposed a gradient elution mode. The critical process parameters (CPPs) studied in this research were acetonitrile content at the beginning of gradient program, acetonitrile content at the end of gradient program and the gradient time. Plan of experiments was defined by Box-Behnken design. The experimental domains of the three selected factors x1 - content of the acetonitrile at the start of linear gradient, x2 - content of the acetonitrile at the end of linear gradient and x3 - gradient time (t(G)) were 110%, 30%], [48%, 60%] and [8 min, 15 min], respectively. In order to define the design space (DS) as a zone where the desired quality criteria is met providing also the quality assurance, Monte Carlo simulations were performed. The uniform error distribution equal to the calculated standard error was added to the model coefficient estimates. Monte Carlo simulation included 5000 iterations in each of 3969 defined grid points and the region having the probability pi >= 95% to achieve satisfactory values of all defined CQAs was computed. As a working point, following chromatographic conditions suited in the middle of the DS were chosen: 22% acetonitrile at the start of gradient program, 55.5% acetonitrile at the end of gradient program end and the gradient time of 11.5 min. The developed method was validated in order to prove its reliability.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Development of liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality-by-design methodology
VL  - 111
SP  - 7
EP  - 13
DO  - 10.1016/j.jpba.2015.03.009
ER  - 

@article{
author = "Pantović, Jasmina and Malenović, Anđelija and Vemić, Ana and Kostić, Nada and Medenica, Mirjana",
year = "2015",
abstract = "In this paper, the development of reversed-phase liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality by design (QbD) approach is presented. The defined analytical target profile (ATP) was the efficient baseline separation and the accurate determination of the investigated analytes. The selected critical quality attributes (CQAs) were the separation criterions between the critical peak pairs because the mixture complexity imposed a gradient elution mode. The critical process parameters (CPPs) studied in this research were acetonitrile content at the beginning of gradient program, acetonitrile content at the end of gradient program and the gradient time. Plan of experiments was defined by Box-Behnken design. The experimental domains of the three selected factors x1 - content of the acetonitrile at the start of linear gradient, x2 - content of the acetonitrile at the end of linear gradient and x3 - gradient time (t(G)) were 110%, 30%], [48%, 60%] and [8 min, 15 min], respectively. In order to define the design space (DS) as a zone where the desired quality criteria is met providing also the quality assurance, Monte Carlo simulations were performed. The uniform error distribution equal to the calculated standard error was added to the model coefficient estimates. Monte Carlo simulation included 5000 iterations in each of 3969 defined grid points and the region having the probability pi >= 95% to achieve satisfactory values of all defined CQAs was computed. As a working point, following chromatographic conditions suited in the middle of the DS were chosen: 22% acetonitrile at the start of gradient program, 55.5% acetonitrile at the end of gradient program end and the gradient time of 11.5 min. The developed method was validated in order to prove its reliability.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Development of liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality-by-design methodology",
volume = "111",
pages = "7-13",
doi = "10.1016/j.jpba.2015.03.009"
}

Pantović, J., Malenović, A., Vemić, A., Kostić, N.,& Medenica, M.. (2015). Development of liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality-by-design methodology. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 111, 7-13.
https://doi.org/10.1016/j.jpba.2015.03.009

Pantović J, Malenović A, Vemić A, Kostić N, Medenica M. Development of liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality-by-design methodology. in Journal of Pharmaceutical and Biomedical Analysis. 2015;111:7-13.
doi:10.1016/j.jpba.2015.03.009 .

Pantović, Jasmina, Malenović, Anđelija, Vemić, Ana, Kostić, Nada, Medenica, Mirjana, "Development of liquid chromatographic method for the analysis of dabigatran etexilate mesilate and its ten impurities supported by quality-by-design methodology" in Journal of Pharmaceutical and Biomedical Analysis, 111 (2015):7-13,
https://doi.org/10.1016/j.jpba.2015.03.009 . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Rakić, Tijana
AU  - Malenović, Anđelija
AU  - Medenica, Mirjana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2379
AB  - The aim of this paper is to present a development of liquid chromatographic method when chaotropic salts are used as mobile phase additives following the QbD principles. The effect of critical process parameters (column chemistry, salt nature and concentration, acetonitrile content and column temperature) on the critical quality attributes (retention of the first and last eluting peak and separation of the critical peak pairs) was studied applying the design of experiments-design space methodology (DoE-DS). D-optimal design is chosen in order to simultaneously examine both categorical and numerical factors in minimal number of experiments. Two ways for the achievement of quality assurance were performed and compared. Namely, the uncertainty originating from the models was assessed by Monte Carlo simulations propagating the error equal to the variance of the model residuals and propagating the error originating from the model coefficients' calculation. The baseline separation of pramipexole and its five impurities is achieved fulfilling all the required criteria while the method validation proved its reliability.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles
VL  - 102
SP  - 314
EP  - 320
DO  - 10.1016/j.jpba.2014.09.031
ER  - 

@article{
author = "Vemić, Ana and Rakić, Tijana and Malenović, Anđelija and Medenica, Mirjana",
year = "2015",
abstract = "The aim of this paper is to present a development of liquid chromatographic method when chaotropic salts are used as mobile phase additives following the QbD principles. The effect of critical process parameters (column chemistry, salt nature and concentration, acetonitrile content and column temperature) on the critical quality attributes (retention of the first and last eluting peak and separation of the critical peak pairs) was studied applying the design of experiments-design space methodology (DoE-DS). D-optimal design is chosen in order to simultaneously examine both categorical and numerical factors in minimal number of experiments. Two ways for the achievement of quality assurance were performed and compared. Namely, the uncertainty originating from the models was assessed by Monte Carlo simulations propagating the error equal to the variance of the model residuals and propagating the error originating from the model coefficients' calculation. The baseline separation of pramipexole and its five impurities is achieved fulfilling all the required criteria while the method validation proved its reliability.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles",
volume = "102",
pages = "314-320",
doi = "10.1016/j.jpba.2014.09.031"
}

Vemić, A., Rakić, T., Malenović, A.,& Medenica, M.. (2015). Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 102, 314-320.
https://doi.org/10.1016/j.jpba.2014.09.031

Vemić A, Rakić T, Malenović A, Medenica M. Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles. in Journal of Pharmaceutical and Biomedical Analysis. 2015;102:314-320.
doi:10.1016/j.jpba.2014.09.031 .

Vemić, Ana, Rakić, Tijana, Malenović, Anđelija, Medenica, Mirjana, "Chaotropic salts in liquid chromatographic method development for the determination of pramipexole and its impurities following quality-by-design principles" in Journal of Pharmaceutical and Biomedical Analysis, 102 (2015):314-320,
https://doi.org/10.1016/j.jpba.2014.09.031 . .

TY  - JOUR
AU  - Drakul, Dragana
AU  - Matić, Predrag
AU  - Drobac, Milica
AU  - Kostić, Nađa
AU  - Vemić, Ana
AU  - Vasiljević, Dragana
AU  - Malenović, Anđelija
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2291
AB  - Vascular stents are general medical devices of class III or IIb, which are placed along the walls of the constricted coronary and peripheral blood vessels thus keeping them viable. According to the mechanism of expansion, stents may be balloon-expandable or self-expanding. Depending on the geometry they can be classified into: coil stents, open-cell modular stents and multi-cell closed cell stents. The most important characteristic of vascular stents is their flexibility, but a number of additional requirements must also be met: high radial strength, low elastic deformation, small diameter, the possibility of monitoring through the bloodstream, minimum subsequent shortening, minimum elastic longitudinal deformation, and the optimal retention at target site. Materials for production of stents must be biologically inert, visible by radiological techniques, biocompatible, corrosion-resistant and resistant to stress due to blood flow. The most significant adverse event after stent implantation is the occurrence of restenosis, which is most efficiently overcome by the application of drug releasing stents. These stents are composed of three parts: stent platform, drug carrier and a drug that inhibits neointimal hyperplasia - paclitaxel and limuses (sirolimus, everolimus, zotarolimus, tacrolimus, pimecrolimus, etc.). In recent years, stents with surfaces coated with substances that accelerate endothelialisation and thus reduce thrombosis have been developed. The latest approach is represented by a stent with the lumen coated with CD34 antibody, and the outer side coated with sirolimus. By using these devices a double effect is achieved: acceleration of endothelialisation and inhibition of neointimal hyperplasia.
AB  - Vaskularni stentovi su opšta medicinska sredstva klase III ili IIb, koja se postavljaju uz zidove koronarnih i perifernih krvnih sudova kada postoji suženje i na taj način ih održavaju prohodnim. Prema mehanizmu ekspanzije, stentovi mogu biti balon-ekspandirajući ili samoekspandirajući, a u zavisnosti od geometrijskog oblika dele se na: stentove u obliku spirale, modularne stentove sa otvorenim ćelijama i multićelijske stentove sa zatvorenim ćelijama. Najznačajnija karakteristika vaskularnih stentova je fleksibilnost, ali moraju da ispunjavaju i čitav niz dodatnih zahteva, kao što su: velika radijalna snaga, nizak stepen elastične deformacije, mali prečnik, mogućnost praćenja kroz krvotok, minimalno naknadno skraćivanje, minimalna elastična longitudinalna deformacija i optimalno zadržavanje na ciljnom mestu. Materijali za proizvodnju stentova moraju biti biološki inertni, vidljivi radiološkim tehnikama, biokompatibilni, otporni na koroziju i otporni na stres zbog protoka krvi. Najznačajniji neželjeni događaj nakon ugradnje stentova je pojava restenoze, koja se najefikasnije prevazilazi primenom stentova koji oslobađaju lek. Ovi stentovi se sastoje iz tri dela: platforme stenta, nosača leka i leka koji inhibira neointimalnu hiperplaziju, paklitaksel i limusi (sirolimus, everolimus, zotarolimus, takrolimus, pimekrolimus i dr). Poslednjih godina razvijeni su i stentovi kod kojih se površine oblažu supstancama koje ubrzavaju endotelizaciju i tako smanjuju trombozu. Najnoviji pristup predstavlja stent kod koga se lumen stenta oblaže CD34 antitelom, a spoljašnja strana sirolimusom. Primenom ovih stentova postiže se dvostruki efekat: ubrzavanje endotelizacije i inhibicija neointimalne hiperplazije.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Vascular stents: The most important types and characteristics
T1  - Vaskularni stentovi - najznačajnije vrste i osobine
VL  - 64
IS  - 5
SP  - 421
EP  - 437
DO  - 10.5937/arhfarm1405421D
ER  - 

@article{
author = "Drakul, Dragana and Matić, Predrag and Drobac, Milica and Kostić, Nađa and Vemić, Ana and Vasiljević, Dragana and Malenović, Anđelija",
year = "2014",
abstract = "Vascular stents are general medical devices of class III or IIb, which are placed along the walls of the constricted coronary and peripheral blood vessels thus keeping them viable. According to the mechanism of expansion, stents may be balloon-expandable or self-expanding. Depending on the geometry they can be classified into: coil stents, open-cell modular stents and multi-cell closed cell stents. The most important characteristic of vascular stents is their flexibility, but a number of additional requirements must also be met: high radial strength, low elastic deformation, small diameter, the possibility of monitoring through the bloodstream, minimum subsequent shortening, minimum elastic longitudinal deformation, and the optimal retention at target site. Materials for production of stents must be biologically inert, visible by radiological techniques, biocompatible, corrosion-resistant and resistant to stress due to blood flow. The most significant adverse event after stent implantation is the occurrence of restenosis, which is most efficiently overcome by the application of drug releasing stents. These stents are composed of three parts: stent platform, drug carrier and a drug that inhibits neointimal hyperplasia - paclitaxel and limuses (sirolimus, everolimus, zotarolimus, tacrolimus, pimecrolimus, etc.). In recent years, stents with surfaces coated with substances that accelerate endothelialisation and thus reduce thrombosis have been developed. The latest approach is represented by a stent with the lumen coated with CD34 antibody, and the outer side coated with sirolimus. By using these devices a double effect is achieved: acceleration of endothelialisation and inhibition of neointimal hyperplasia., Vaskularni stentovi su opšta medicinska sredstva klase III ili IIb, koja se postavljaju uz zidove koronarnih i perifernih krvnih sudova kada postoji suženje i na taj način ih održavaju prohodnim. Prema mehanizmu ekspanzije, stentovi mogu biti balon-ekspandirajući ili samoekspandirajući, a u zavisnosti od geometrijskog oblika dele se na: stentove u obliku spirale, modularne stentove sa otvorenim ćelijama i multićelijske stentove sa zatvorenim ćelijama. Najznačajnija karakteristika vaskularnih stentova je fleksibilnost, ali moraju da ispunjavaju i čitav niz dodatnih zahteva, kao što su: velika radijalna snaga, nizak stepen elastične deformacije, mali prečnik, mogućnost praćenja kroz krvotok, minimalno naknadno skraćivanje, minimalna elastična longitudinalna deformacija i optimalno zadržavanje na ciljnom mestu. Materijali za proizvodnju stentova moraju biti biološki inertni, vidljivi radiološkim tehnikama, biokompatibilni, otporni na koroziju i otporni na stres zbog protoka krvi. Najznačajniji neželjeni događaj nakon ugradnje stentova je pojava restenoze, koja se najefikasnije prevazilazi primenom stentova koji oslobađaju lek. Ovi stentovi se sastoje iz tri dela: platforme stenta, nosača leka i leka koji inhibira neointimalnu hiperplaziju, paklitaksel i limusi (sirolimus, everolimus, zotarolimus, takrolimus, pimekrolimus i dr). Poslednjih godina razvijeni su i stentovi kod kojih se površine oblažu supstancama koje ubrzavaju endotelizaciju i tako smanjuju trombozu. Najnoviji pristup predstavlja stent kod koga se lumen stenta oblaže CD34 antitelom, a spoljašnja strana sirolimusom. Primenom ovih stentova postiže se dvostruki efekat: ubrzavanje endotelizacije i inhibicija neointimalne hiperplazije.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Vascular stents: The most important types and characteristics, Vaskularni stentovi - najznačajnije vrste i osobine",
volume = "64",
number = "5",
pages = "421-437",
doi = "10.5937/arhfarm1405421D"
}

Drakul, D., Matić, P., Drobac, M., Kostić, N., Vemić, A., Vasiljević, D.,& Malenović, A.. (2014). Vascular stents: The most important types and characteristics. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 64(5), 421-437.
https://doi.org/10.5937/arhfarm1405421D

Drakul D, Matić P, Drobac M, Kostić N, Vemić A, Vasiljević D, Malenović A. Vascular stents: The most important types and characteristics. in Arhiv za farmaciju. 2014;64(5):421-437.
doi:10.5937/arhfarm1405421D .

Drakul, Dragana, Matić, Predrag, Drobac, Milica, Kostić, Nađa, Vemić, Ana, Vasiljević, Dragana, Malenović, Anđelija, "Vascular stents: The most important types and characteristics" in Arhiv za farmaciju, 64, no. 5 (2014):421-437,
https://doi.org/10.5937/arhfarm1405421D . .

TY  - JOUR
AU  - Perović, Ivana
AU  - Malenović, Anđelija
AU  - Vemić, Ana
AU  - Kostić, Nađa
AU  - Ivanović, Darko
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2242
AB  - In this paper the experimental conditions for optimal reversed-phase liquid chromatographic (RP-HPLC) determination of sulfamethoxazole, trimethoprim and preservatives, as well as degradation products of sulfamethoxazole and trimethoprim in syrup were defined. The determination of active compounds and preservatives was carried out on Zorbax Eclipse XDB-C18, 150 mm × 4.6 mm, 5 μm particle size column, mobile phase flow rate was 1.5 mL min-1, and detection at 235 nm for the active compounds and 254 nm for preservatives. Mobile phase A consisted of 150 mL of acetonitrile, 850 mL of water and 1 mL of triethanolamine (pH 5.90 adjusted with diluted acetic acid), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. For the determination of degradation products Zorbax Eclipse Plus C18, 100 mm x 4.6 mm, 3.5 μm particle size column was used, the mobile phase flow rate was 0.5 mL min-1 and detection at 210 nm for 3,4,5-trimethoxybenzoic acid and 254 nm for sulfanilic acid and sulfanilamide. Mobile phase A was 50 mM potassium dihydrogenphosphate (pH 5.60 adjusted with a 0.5 mol L-1 potassium hydroxide), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. Through the validation of the developed methods their efficiency and reliability is confirmed and consequently the adequacy for the routine control.
AB  - U ovom radu prikazano je definisanje eksperimentalnih uslova i optimizacija metoda reverzno-fazne tečne hromatografije (RP-HPLC) za određivanje sulfametoksazola, trimetoprima i konzervanasa, odnosno degradacionih proizvoda sulfametoksazola i trimetoprima u sirupu. Određivanje sadržaja aktivnih komponenti i konzervanasa vršeno je na koloni Zorbax Eclipse XDB-C18, 150 mm × 4,6 mm, 5 μm veličine čestica, protok mobilne faze bio je 1,5 mL min-1, dok je detekcija vršena na 235 nm za aktivne komponente i 254 nm za konzervanse. Mobilna faza A sastojala se od smeše 150 mL acetonitrila, 850 mL vode i 1 mL trietanolamina (pH 5,9 podešen razblaženom sirćetnom kiselinom), a kao mobilna faza B korišćen je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Određivanje sadržaja degradacionih proizvoda vršeno je na koloni Zorbax Eclipse Plus-C18, 100 mm × 4,6 mm, 3,5 μm veličine čestica, uz protok mobilne faze od 0,5 mL min-1 i detekciju na 210 nm za 3,4,5-trimetoksibenzojevu kiselinu i 254 nm za sulfanilnu kiselinu i sulfanilamid. Mobilna faza A bila je 50 mM kalijum-dihidrogenfosfat (pH 5,60 podešen sa 0,5 mol L-1 kalijum-hidroksidom), a mobilna faza B bio je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Validacijom postavljenih metoda potvrđeno je da su efikasne i pouzdane, i kao takve pogodne za rutinsku kontrolu.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Development of chromatographic methods for analysis of sulfamethoxazole, trimethoprim, their degradation products and preservatives in syrup
T1  - Razvoj hromatografskih metoda za analizu sulfametoksazola, trimetoprima, njihovih degradacionih proizvoda i konzervanasa u sirupu
VL  - 64
IS  - 2
SP  - 112
EP  - 127
DO  - 10.5937/arhfarm1402112P
ER  - 

@article{
author = "Perović, Ivana and Malenović, Anđelija and Vemić, Ana and Kostić, Nađa and Ivanović, Darko",
year = "2014",
abstract = "In this paper the experimental conditions for optimal reversed-phase liquid chromatographic (RP-HPLC) determination of sulfamethoxazole, trimethoprim and preservatives, as well as degradation products of sulfamethoxazole and trimethoprim in syrup were defined. The determination of active compounds and preservatives was carried out on Zorbax Eclipse XDB-C18, 150 mm × 4.6 mm, 5 μm particle size column, mobile phase flow rate was 1.5 mL min-1, and detection at 235 nm for the active compounds and 254 nm for preservatives. Mobile phase A consisted of 150 mL of acetonitrile, 850 mL of water and 1 mL of triethanolamine (pH 5.90 adjusted with diluted acetic acid), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. For the determination of degradation products Zorbax Eclipse Plus C18, 100 mm x 4.6 mm, 3.5 μm particle size column was used, the mobile phase flow rate was 0.5 mL min-1 and detection at 210 nm for 3,4,5-trimethoxybenzoic acid and 254 nm for sulfanilic acid and sulfanilamide. Mobile phase A was 50 mM potassium dihydrogenphosphate (pH 5.60 adjusted with a 0.5 mol L-1 potassium hydroxide), while mobile phase B was acetonitrile. The mobile phase ratio was defined by the gradient program. Through the validation of the developed methods their efficiency and reliability is confirmed and consequently the adequacy for the routine control., U ovom radu prikazano je definisanje eksperimentalnih uslova i optimizacija metoda reverzno-fazne tečne hromatografije (RP-HPLC) za određivanje sulfametoksazola, trimetoprima i konzervanasa, odnosno degradacionih proizvoda sulfametoksazola i trimetoprima u sirupu. Određivanje sadržaja aktivnih komponenti i konzervanasa vršeno je na koloni Zorbax Eclipse XDB-C18, 150 mm × 4,6 mm, 5 μm veličine čestica, protok mobilne faze bio je 1,5 mL min-1, dok je detekcija vršena na 235 nm za aktivne komponente i 254 nm za konzervanse. Mobilna faza A sastojala se od smeše 150 mL acetonitrila, 850 mL vode i 1 mL trietanolamina (pH 5,9 podešen razblaženom sirćetnom kiselinom), a kao mobilna faza B korišćen je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Određivanje sadržaja degradacionih proizvoda vršeno je na koloni Zorbax Eclipse Plus-C18, 100 mm × 4,6 mm, 3,5 μm veličine čestica, uz protok mobilne faze od 0,5 mL min-1 i detekciju na 210 nm za 3,4,5-trimetoksibenzojevu kiselinu i 254 nm za sulfanilnu kiselinu i sulfanilamid. Mobilna faza A bila je 50 mM kalijum-dihidrogenfosfat (pH 5,60 podešen sa 0,5 mol L-1 kalijum-hidroksidom), a mobilna faza B bio je acetonitril. Odnos mobilnih faza tokom analize definisan je programom gradijenta. Validacijom postavljenih metoda potvrđeno je da su efikasne i pouzdane, i kao takve pogodne za rutinsku kontrolu.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Development of chromatographic methods for analysis of sulfamethoxazole, trimethoprim, their degradation products and preservatives in syrup, Razvoj hromatografskih metoda za analizu sulfametoksazola, trimetoprima, njihovih degradacionih proizvoda i konzervanasa u sirupu",
volume = "64",
number = "2",
pages = "112-127",
doi = "10.5937/arhfarm1402112P"
}

Perović, I., Malenović, A., Vemić, A., Kostić, N.,& Ivanović, D.. (2014). Development of chromatographic methods for analysis of sulfamethoxazole, trimethoprim, their degradation products and preservatives in syrup. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 64(2), 112-127.
https://doi.org/10.5937/arhfarm1402112P

Perović I, Malenović A, Vemić A, Kostić N, Ivanović D. Development of chromatographic methods for analysis of sulfamethoxazole, trimethoprim, their degradation products and preservatives in syrup. in Arhiv za farmaciju. 2014;64(2):112-127.
doi:10.5937/arhfarm1402112P .

Perović, Ivana, Malenović, Anđelija, Vemić, Ana, Kostić, Nađa, Ivanović, Darko, "Development of chromatographic methods for analysis of sulfamethoxazole, trimethoprim, their degradation products and preservatives in syrup" in Arhiv za farmaciju, 64, no. 2 (2014):112-127,
https://doi.org/10.5937/arhfarm1402112P . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Malenović, Anđelija
AU  - Medenica, Mirjana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2231
AB  - Chaotropic agents recently gained popularity as interesting and useful mobile phase additives in liquid chromatography due to their effect on analytes retention, peak symmetry and separation efficiency. They mimic the role of classical ion-pairing agents, but with less drawbacks, so their use becomes attractive in the field of pharmaceutical analysis. In this paper, the influence of sodium trifluoroacetate and sodium perchlorate on the chromatographic behavior of ropinirole and its impurities is examined. By the extended thermodynamic approach, it was shown that the separation in the given system was predominantly governed by electrostatic interactions between the protonated analytes and the charged surface of the stationary phase, but the ion-pair complex formation in the eluent also proved to be significant. Further, the employment of face-centered central composite design enabled the understanding of the effect of chaotropic agent concentration and its interactions with other factors (acetonitrile content and pH of the water phase) that influence the given chromatographic system. Finally, the same data was used for multi-objective optimization based on the grid point search method. After the method validation, the adequacy of the suggested approach in development of methods for routine pharmaceutical analysis was proven.
PB  - Elsevier Science BV, Amsterdam
T2  - Talanta
T1  - The influence of inorganic salts with chaotropic properties on the chromatographic behavior of ropinirole and its two impurities
VL  - 123
SP  - 122
EP  - 127
DO  - 10.1016/j.talanta.2014.02.006
ER  - 

@article{
author = "Vemić, Ana and Malenović, Anđelija and Medenica, Mirjana",
year = "2014",
abstract = "Chaotropic agents recently gained popularity as interesting and useful mobile phase additives in liquid chromatography due to their effect on analytes retention, peak symmetry and separation efficiency. They mimic the role of classical ion-pairing agents, but with less drawbacks, so their use becomes attractive in the field of pharmaceutical analysis. In this paper, the influence of sodium trifluoroacetate and sodium perchlorate on the chromatographic behavior of ropinirole and its impurities is examined. By the extended thermodynamic approach, it was shown that the separation in the given system was predominantly governed by electrostatic interactions between the protonated analytes and the charged surface of the stationary phase, but the ion-pair complex formation in the eluent also proved to be significant. Further, the employment of face-centered central composite design enabled the understanding of the effect of chaotropic agent concentration and its interactions with other factors (acetonitrile content and pH of the water phase) that influence the given chromatographic system. Finally, the same data was used for multi-objective optimization based on the grid point search method. After the method validation, the adequacy of the suggested approach in development of methods for routine pharmaceutical analysis was proven.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Talanta",
title = "The influence of inorganic salts with chaotropic properties on the chromatographic behavior of ropinirole and its two impurities",
volume = "123",
pages = "122-127",
doi = "10.1016/j.talanta.2014.02.006"
}

Vemić, A., Malenović, A.,& Medenica, M.. (2014). The influence of inorganic salts with chaotropic properties on the chromatographic behavior of ropinirole and its two impurities. in Talanta
Elsevier Science BV, Amsterdam., 123, 122-127.
https://doi.org/10.1016/j.talanta.2014.02.006

Vemić A, Malenović A, Medenica M. The influence of inorganic salts with chaotropic properties on the chromatographic behavior of ropinirole and its two impurities. in Talanta. 2014;123:122-127.
doi:10.1016/j.talanta.2014.02.006 .

Vemić, Ana, Malenović, Anđelija, Medenica, Mirjana, "The influence of inorganic salts with chaotropic properties on the chromatographic behavior of ropinirole and its two impurities" in Talanta, 123 (2014):122-127,
https://doi.org/10.1016/j.talanta.2014.02.006 . .

TY  - JOUR
AU  - Colović, Jelena
AU  - Vemić, Ana
AU  - Kostić, Nada
AU  - Malenović, Anđelija
AU  - Medenica, Mirjana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2092
AB  - In this paper, the capability of a polynomial-modified Gaussian model to relate the peak shape of basic analytes, amlodipine, and its impurity A, with the change of chromatographic conditions was tested. For the accurate simulation of real chromatographic peaks the authors proposed the three-step procedure based on indirect modeling of peak width at 10% of peak height (W-0.1), individual values of left-half width (A) and right-half width (B), number of theoretical plates (N), and tailing factor (Tf). The values of retention factors corresponding to the peak beginning (k(B)), peak apex (k(A)), peak ending (k(E)), and peak heights (H-0) of the analytes were directly modeled. Then, the investigated experimental domain was divided to acquire a grid of appropriate density, which allowed the subsequent calculation of W-0.1, A, B, N, and Tf. On the basis of the predicted results for Tf and N, as well as the defined criteria for the simulation the following conditions were selected: 33% acetonitrile/67% aqueous phase (55 mM perchloric acid, pH 2.2) at 40 degrees C column temperature. Perfect agreement between predicted and experimental values was obtained confirming the ability of polynomial modified Gaussian model and three-step procedure to successfully simulate the real chromatograms in ion-interaction chromatography.
PB  - Wiley-VCH Verlag GMBH, Weinheim
T2  - Journal of Separation Science
T1  - Testing the capability of a polynomial-modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion-interaction chromatography
VL  - 37
IS  - 14
SP  - 1797
EP  - 1804
DO  - 10.1002/jssc.201400206
ER  - 

@article{
author = "Colović, Jelena and Vemić, Ana and Kostić, Nada and Malenović, Anđelija and Medenica, Mirjana",
year = "2014",
abstract = "In this paper, the capability of a polynomial-modified Gaussian model to relate the peak shape of basic analytes, amlodipine, and its impurity A, with the change of chromatographic conditions was tested. For the accurate simulation of real chromatographic peaks the authors proposed the three-step procedure based on indirect modeling of peak width at 10% of peak height (W-0.1), individual values of left-half width (A) and right-half width (B), number of theoretical plates (N), and tailing factor (Tf). The values of retention factors corresponding to the peak beginning (k(B)), peak apex (k(A)), peak ending (k(E)), and peak heights (H-0) of the analytes were directly modeled. Then, the investigated experimental domain was divided to acquire a grid of appropriate density, which allowed the subsequent calculation of W-0.1, A, B, N, and Tf. On the basis of the predicted results for Tf and N, as well as the defined criteria for the simulation the following conditions were selected: 33% acetonitrile/67% aqueous phase (55 mM perchloric acid, pH 2.2) at 40 degrees C column temperature. Perfect agreement between predicted and experimental values was obtained confirming the ability of polynomial modified Gaussian model and three-step procedure to successfully simulate the real chromatograms in ion-interaction chromatography.",
publisher = "Wiley-VCH Verlag GMBH, Weinheim",
journal = "Journal of Separation Science",
title = "Testing the capability of a polynomial-modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion-interaction chromatography",
volume = "37",
number = "14",
pages = "1797-1804",
doi = "10.1002/jssc.201400206"
}

Colović, J., Vemić, A., Kostić, N., Malenović, A.,& Medenica, M.. (2014). Testing the capability of a polynomial-modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion-interaction chromatography. in Journal of Separation Science
Wiley-VCH Verlag GMBH, Weinheim., 37(14), 1797-1804.
https://doi.org/10.1002/jssc.201400206

Colović J, Vemić A, Kostić N, Malenović A, Medenica M. Testing the capability of a polynomial-modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion-interaction chromatography. in Journal of Separation Science. 2014;37(14):1797-1804.
doi:10.1002/jssc.201400206 .

Colović, Jelena, Vemić, Ana, Kostić, Nada, Malenović, Anđelija, Medenica, Mirjana, "Testing the capability of a polynomial-modified gaussian model in the description and simulation of chromatographic peaks of amlodipine and its impurity in ion-interaction chromatography" in Journal of Separation Science, 37, no. 14 (2014):1797-1804,
https://doi.org/10.1002/jssc.201400206 . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Malenović, Anđelija
AU  - Rakić, Tijana
AU  - Kostić, Nada
AU  - Jančić-Stojanović, Biljana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2079
AB  - Certain chemometrical tools allow an efficient way to provide valuable data to evaluate the retention behavior of analytes in liquid chromatography. In this study of the retention behavior of azole antifungals, the experimental design was applied in combination with artificial neural networks (ANNs). Three potentially significant factors (methanol content, pH of the mobile phase and column temperature) were incorporated in the plan of experiments, defined by central composite design. As the system outputs, the retention factors of all six investigated substances (fluconazole, ketoconazole, bifonazole, clotrimazole, econazole and miconazole) were determined. The pattern for the analyzed behavior of the system was created by employing ANNs. The final, optimized topology of the highly predictive network was 3-8-6. Twelve experiments were used in a training set, whereas a back-propagation algorithm was optimal for network training. The ability of the defined network to predict the retention of the investigated azoles was confirmed by correlations higher than 0.9912 for all analytes. The presented approach allowed the adequate prediction of the retention behavior of azoles, in addition to the extraction of important information for a better understanding of the analyzed system.
PB  - Oxford Univ Press Inc, Cary
T2  - Journal of Chromatographic Science
T1  - Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals
VL  - 52
IS  - 2
SP  - 95
EP  - 102
DO  - 10.1093/chromsci/bms211
ER  - 

@article{
author = "Vemić, Ana and Malenović, Anđelija and Rakić, Tijana and Kostić, Nada and Jančić-Stojanović, Biljana",
year = "2014",
abstract = "Certain chemometrical tools allow an efficient way to provide valuable data to evaluate the retention behavior of analytes in liquid chromatography. In this study of the retention behavior of azole antifungals, the experimental design was applied in combination with artificial neural networks (ANNs). Three potentially significant factors (methanol content, pH of the mobile phase and column temperature) were incorporated in the plan of experiments, defined by central composite design. As the system outputs, the retention factors of all six investigated substances (fluconazole, ketoconazole, bifonazole, clotrimazole, econazole and miconazole) were determined. The pattern for the analyzed behavior of the system was created by employing ANNs. The final, optimized topology of the highly predictive network was 3-8-6. Twelve experiments were used in a training set, whereas a back-propagation algorithm was optimal for network training. The ability of the defined network to predict the retention of the investigated azoles was confirmed by correlations higher than 0.9912 for all analytes. The presented approach allowed the adequate prediction of the retention behavior of azoles, in addition to the extraction of important information for a better understanding of the analyzed system.",
publisher = "Oxford Univ Press Inc, Cary",
journal = "Journal of Chromatographic Science",
title = "Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals",
volume = "52",
number = "2",
pages = "95-102",
doi = "10.1093/chromsci/bms211"
}

Vemić, A., Malenović, A., Rakić, T., Kostić, N.,& Jančić-Stojanović, B.. (2014). Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals. in Journal of Chromatographic Science
Oxford Univ Press Inc, Cary., 52(2), 95-102.
https://doi.org/10.1093/chromsci/bms211

Vemić A, Malenović A, Rakić T, Kostić N, Jančić-Stojanović B. Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals. in Journal of Chromatographic Science. 2014;52(2):95-102.
doi:10.1093/chromsci/bms211 .

Vemić, Ana, Malenović, Anđelija, Rakić, Tijana, Kostić, Nada, Jančić-Stojanović, Biljana, "Chemometrical Tools in the Study of the Retention Behavior of Azole Antifungals" in Journal of Chromatographic Science, 52, no. 2 (2014):95-102,
https://doi.org/10.1093/chromsci/bms211 . .

TY  - JOUR
AU  - Drobac, Milica
AU  - Jeremić, Veljko
AU  - Kostić, Nađa
AU  - Vemić, Ana
AU  - Vasiljević, Dragana
AU  - Malenović, Anđelija
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2046
AB  - Overall, the medical devices used in the treatment of wounds could be divided into traditional dressings, modern dressings (with advanced features), skin replacement products and wound healing devices. This paper provides an overview of traditional dressings, their most important characteristics and their common usage. Traditional dressings include cotton wool, gauzes, bandages and wound dressing pads. According to the Regulation on the classification of general medical devices, given traditional dressings are classified into Class I, if used as a mechanical barrier, for compression or for absorption of the fluid from the wound (e.g. cotton wool, gauzes, compresses, bandages and the like), or into Class IIa, if they possess specific characteristics to support the wound healing and have properties that regulate humidity, temperature, levels of oxygen and other gases, pH value, and the wound microenvironment (e.g. paraffin impregnated gauze). The advantages of the traditional dressings reflect in their ability to stop the bleeding, to stabilize the wound and in their low price. The disadvantages are that they usually adhere to the wound, do not maintain the moisture and need an often change.
AB  - Sveobuhvatna podela medicinskih sredstava koja se koriste za obradu rana je na konvencionalna sredstva, savremena sredstva (sa unapređenim karakteristikama), sredstva koja predstavljaju zamenu za kožu i sredstva za zaceljivanje kože. U ovom radu dat je pregled konvencionalnih medicinskih sredstava koja se koriste za obradu rana, njihove najznačajnije osobine i uobičajena upotreba. Konvencionalna medicinska sredstva koja se koriste za obradu rana su vate, gaze, zavoji i sredstva za prekrivanje rane. Prema Pravilniku o klasifikaciji opštih medicinskih sredstava, navedena konvencionalna medicinska sredstva se svrstavaju u Klasu I, ako se upotrebljavaju kao mehanička prepreka, za kompresiju ili upijanje tečnosti iz rana (npr. vate, gaze, komprese, zavoji i sl.), ili u Klasu IIa, kada imaju specifične karakteristike da potpomažu proces isceljivanja rana i imaju svojstva da regulišu vlagu, temperaturu, nivo kiseonika i drugih gasova, pH vrednost, odnosno mikrookolinu rane (npr. parafinske (vazelinske) gaze). Prednosti primene konvencionalnih medicinskih sredstava za obradu rana su: zaustavljanje krvarenja, stabilizacija rane, kao i niska cena. Nedostaci su što se obično lepe za ranu, ne održavaju odgovarajuću vlažnost rane i što moraju često da se menjaju.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Konvencionalna medicinska sredstva za obradu rana - osobine i upotreba
T1  - Traditional medical devices in wound treatment -
characteristics and usage
VL  - 63
IS  - 6
SP  - 513
EP  - 527
UR  - https://hdl.handle.net/21.15107/rcub_farfar_2046
ER  - 

@article{
author = "Drobac, Milica and Jeremić, Veljko and Kostić, Nađa and Vemić, Ana and Vasiljević, Dragana and Malenović, Anđelija",
year = "2013",
abstract = "Overall, the medical devices used in the treatment of wounds could be divided into traditional dressings, modern dressings (with advanced features), skin replacement products and wound healing devices. This paper provides an overview of traditional dressings, their most important characteristics and their common usage. Traditional dressings include cotton wool, gauzes, bandages and wound dressing pads. According to the Regulation on the classification of general medical devices, given traditional dressings are classified into Class I, if used as a mechanical barrier, for compression or for absorption of the fluid from the wound (e.g. cotton wool, gauzes, compresses, bandages and the like), or into Class IIa, if they possess specific characteristics to support the wound healing and have properties that regulate humidity, temperature, levels of oxygen and other gases, pH value, and the wound microenvironment (e.g. paraffin impregnated gauze). The advantages of the traditional dressings reflect in their ability to stop the bleeding, to stabilize the wound and in their low price. The disadvantages are that they usually adhere to the wound, do not maintain the moisture and need an often change., Sveobuhvatna podela medicinskih sredstava koja se koriste za obradu rana je na konvencionalna sredstva, savremena sredstva (sa unapređenim karakteristikama), sredstva koja predstavljaju zamenu za kožu i sredstva za zaceljivanje kože. U ovom radu dat je pregled konvencionalnih medicinskih sredstava koja se koriste za obradu rana, njihove najznačajnije osobine i uobičajena upotreba. Konvencionalna medicinska sredstva koja se koriste za obradu rana su vate, gaze, zavoji i sredstva za prekrivanje rane. Prema Pravilniku o klasifikaciji opštih medicinskih sredstava, navedena konvencionalna medicinska sredstva se svrstavaju u Klasu I, ako se upotrebljavaju kao mehanička prepreka, za kompresiju ili upijanje tečnosti iz rana (npr. vate, gaze, komprese, zavoji i sl.), ili u Klasu IIa, kada imaju specifične karakteristike da potpomažu proces isceljivanja rana i imaju svojstva da regulišu vlagu, temperaturu, nivo kiseonika i drugih gasova, pH vrednost, odnosno mikrookolinu rane (npr. parafinske (vazelinske) gaze). Prednosti primene konvencionalnih medicinskih sredstava za obradu rana su: zaustavljanje krvarenja, stabilizacija rane, kao i niska cena. Nedostaci su što se obično lepe za ranu, ne održavaju odgovarajuću vlažnost rane i što moraju često da se menjaju.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Konvencionalna medicinska sredstva za obradu rana - osobine i upotreba, Traditional medical devices in wound treatment -
characteristics and usage",
volume = "63",
number = "6",
pages = "513-527",
url = "https://hdl.handle.net/21.15107/rcub_farfar_2046"
}

Drobac, M., Jeremić, V., Kostić, N., Vemić, A., Vasiljević, D.,& Malenović, A.. (2013). Konvencionalna medicinska sredstva za obradu rana - osobine i upotreba. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 63(6), 513-527.
https://hdl.handle.net/21.15107/rcub_farfar_2046

Drobac M, Jeremić V, Kostić N, Vemić A, Vasiljević D, Malenović A. Konvencionalna medicinska sredstva za obradu rana - osobine i upotreba. in Arhiv za farmaciju. 2013;63(6):513-527.
https://hdl.handle.net/21.15107/rcub_farfar_2046 .

Drobac, Milica, Jeremić, Veljko, Kostić, Nađa, Vemić, Ana, Vasiljević, Dragana, Malenović, Anđelija, "Konvencionalna medicinska sredstva za obradu rana - osobine i upotreba" in Arhiv za farmaciju, 63, no. 6 (2013):513-527,
https://hdl.handle.net/21.15107/rcub_farfar_2046 .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Rakić, Tijana
AU  - Slavković, B
AU  - Kostić, Nada
AU  - Vemić, Ana
AU  - Malenović, Anđelija
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2025
AB  - Method validation presents a detailed investigation of analytical method and provision of the evidence that the method, when correctly applied, produces results that fit to the purpose. In order to achieve the method validation scope efficiently, experimental design presents a very useful tool. The greatest benefits of such approach could be seen in robustness testing through the provision of very useful data about the control of the chromatographic system during the routine application. In this paper, robustness testing of the LC method proposed for the determination of raloxifene hydrochloride and its four impurities was done employing Plackett-Burman design. Applying this design, the effect of five real factors (acetonitrile content, sodium dodecyl sulfate content, column temperature, pH of the mobile phase and flow rate) on the corresponding resolution factors was investigated through twelve experiments. Furthermore, the insignificance intervals for significant factors were calculated and the parameters for system suitability tests were defined. Eventually, the other validation parameters were tested and the effectiveness of the proposed analytical method with a high degree of accuracy was confirmed.
PB  - Xi'an Jiaotong University
T2  - Journal of Pharmaceutical Analysis
T1  - Systematical approach in evaluation of LC method for determination of raloxifene hydrochloride and its impurities employing experimental design
VL  - 3
IS  - 1
SP  - 45
EP  - 52
DO  - 10.1016/j.jpha.2012.09.007
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Rakić, Tijana and Slavković, B and Kostić, Nada and Vemić, Ana and Malenović, Anđelija",
year = "2013",
abstract = "Method validation presents a detailed investigation of analytical method and provision of the evidence that the method, when correctly applied, produces results that fit to the purpose. In order to achieve the method validation scope efficiently, experimental design presents a very useful tool. The greatest benefits of such approach could be seen in robustness testing through the provision of very useful data about the control of the chromatographic system during the routine application. In this paper, robustness testing of the LC method proposed for the determination of raloxifene hydrochloride and its four impurities was done employing Plackett-Burman design. Applying this design, the effect of five real factors (acetonitrile content, sodium dodecyl sulfate content, column temperature, pH of the mobile phase and flow rate) on the corresponding resolution factors was investigated through twelve experiments. Furthermore, the insignificance intervals for significant factors were calculated and the parameters for system suitability tests were defined. Eventually, the other validation parameters were tested and the effectiveness of the proposed analytical method with a high degree of accuracy was confirmed.",
publisher = "Xi'an Jiaotong University",
journal = "Journal of Pharmaceutical Analysis",
title = "Systematical approach in evaluation of LC method for determination of raloxifene hydrochloride and its impurities employing experimental design",
volume = "3",
number = "1",
pages = "45-52",
doi = "10.1016/j.jpha.2012.09.007"
}

Jančić-Stojanović, B., Rakić, T., Slavković, B., Kostić, N., Vemić, A.,& Malenović, A.. (2013). Systematical approach in evaluation of LC method for determination of raloxifene hydrochloride and its impurities employing experimental design. in Journal of Pharmaceutical Analysis
Xi'an Jiaotong University., 3(1), 45-52.
https://doi.org/10.1016/j.jpha.2012.09.007

Jančić-Stojanović B, Rakić T, Slavković B, Kostić N, Vemić A, Malenović A. Systematical approach in evaluation of LC method for determination of raloxifene hydrochloride and its impurities employing experimental design. in Journal of Pharmaceutical Analysis. 2013;3(1):45-52.
doi:10.1016/j.jpha.2012.09.007 .

Jančić-Stojanović, Biljana, Rakić, Tijana, Slavković, B, Kostić, Nada, Vemić, Ana, Malenović, Anđelija, "Systematical approach in evaluation of LC method for determination of raloxifene hydrochloride and its impurities employing experimental design" in Journal of Pharmaceutical Analysis, 3, no. 1 (2013):45-52,
https://doi.org/10.1016/j.jpha.2012.09.007 . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Jančić-Stojanović, Biljana
AU  - Stamenković, Ivana
AU  - Malenović, Anđelija
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1927
AB  - The simultaneous pharmaceutical analysis of multi-component drugs represents a challenge due to a large total number of analytes present in the sample. These analytes are not only the active pharmaceutical ingredients, but also the impurities that might follow the active substances. The aim of this study was to develop an efficient reversed-phase LC method for the simultaneous analysis of antiparkinsonian drugs levodopa, carbidopa and entacapone along with their six related impurities. For the achievement of desirable separation, different acids with anions possessing different properties according to Hofmeister classification (ortho-phosphoric, trifluoroacetic and perchloric acid) were tested. Finally, in order to draw the unbiased conclusions when optimizing the analytical method, for the final tuning of the gradient program, Box-Behnken experimental design and Derringer's desirability function were used. The experiments were performed on Zorbax Extend C18, 150 mm x 4.6 mm, 5 mu m particle size column with the UV detection at 280 nm and mobile phase flow rate of 1 mL/min. The optimal mobile phase consisted of methanol and 20 mM trifluoroacetic acid (pH 2.0 adjusted with NaOH), while their ratio is changed according to previously defined gradient program. The method was tested for selectivity, sensitivity, linearity, accuracy and precision, and proved to be suitable for routine qualitative and quantitative analysis of levodopa, carbidopa, entacapone and their impurities in their mixture.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities
VL  - 77
SP  - 9
EP  - 15
DO  - 10.1016/j.jpba.2013.01.007
ER  - 

@article{
author = "Vemić, Ana and Jančić-Stojanović, Biljana and Stamenković, Ivana and Malenović, Anđelija",
year = "2013",
abstract = "The simultaneous pharmaceutical analysis of multi-component drugs represents a challenge due to a large total number of analytes present in the sample. These analytes are not only the active pharmaceutical ingredients, but also the impurities that might follow the active substances. The aim of this study was to develop an efficient reversed-phase LC method for the simultaneous analysis of antiparkinsonian drugs levodopa, carbidopa and entacapone along with their six related impurities. For the achievement of desirable separation, different acids with anions possessing different properties according to Hofmeister classification (ortho-phosphoric, trifluoroacetic and perchloric acid) were tested. Finally, in order to draw the unbiased conclusions when optimizing the analytical method, for the final tuning of the gradient program, Box-Behnken experimental design and Derringer's desirability function were used. The experiments were performed on Zorbax Extend C18, 150 mm x 4.6 mm, 5 mu m particle size column with the UV detection at 280 nm and mobile phase flow rate of 1 mL/min. The optimal mobile phase consisted of methanol and 20 mM trifluoroacetic acid (pH 2.0 adjusted with NaOH), while their ratio is changed according to previously defined gradient program. The method was tested for selectivity, sensitivity, linearity, accuracy and precision, and proved to be suitable for routine qualitative and quantitative analysis of levodopa, carbidopa, entacapone and their impurities in their mixture.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities",
volume = "77",
pages = "9-15",
doi = "10.1016/j.jpba.2013.01.007"
}

Vemić, A., Jančić-Stojanović, B., Stamenković, I.,& Malenović, A.. (2013). Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 77, 9-15.
https://doi.org/10.1016/j.jpba.2013.01.007

Vemić A, Jančić-Stojanović B, Stamenković I, Malenović A. Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities. in Journal of Pharmaceutical and Biomedical Analysis. 2013;77:9-15.
doi:10.1016/j.jpba.2013.01.007 .

Vemić, Ana, Jančić-Stojanović, Biljana, Stamenković, Ivana, Malenović, Anđelija, "Chaotropic agents in liquid chromatographic method development for the simultaneous analysis of levodopa, carbidopa, entacapone and their impurities" in Journal of Pharmaceutical and Biomedical Analysis, 77 (2013):9-15,
https://doi.org/10.1016/j.jpba.2013.01.007 . .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Vemić, Ana
AU  - Kostić, Nada
AU  - Ivanović, D.
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1916
AB  - In this paper, a chemometrically assisted validation of RP-HPLC method, intended for the quantitative analysis of cefuroxime axetil (A and B), cefuroxime acid, cefuroxime lactone, cefuroxime axetil sulfoxide (A and B), a dagger(3)-cefuroxime axetil and anti cefuroxime axetil (A and B) in tablets, is presented. Since the successful separation could be achieved with the mobile phase containing only methanol and water, Luna C18 column was selected for the analysis. Under these circumstances, the optimization was quite straightforward and included only a fine tuning of the chromatographic conditions to reduce total run time and maintain the achieved separation. The established method was then subjected to the method validation and the required validation parameters were tested. For the robustness evaluation, a fractional factorial 2(4-1) design was utilized and factors that might significantly affect the system performance were defined. For the significant factors, the non-significant intervals were determined and the acceptable system suitability limit for resolution factor between cefuroxime axetil A and cefuroxime axetil a dagger(3) isomer (R (2)) was calculated. As the other validation parameters were also found to be suitable, the possibility to apply the proposed method for the determination of cefuroxime axetil, cefuroxime acid, cefuroxime lactone, cefuroxime axetil sulfoxide, a dagger(3)-cefuroxime axetil and anti cefuroxime axetil in any laboratory under different circumstances is proven.
PB  - Springer Heidelberg, Heidelberg
T2  - Chromatographia
T1  - Evaluation of RP-HPLC Method Intended for the Analysis of Cefuroxime Axetil and ITS Impurities Supported by Experimental Design
VL  - 76
IS  - 5-6
SP  - 293
EP  - 298
DO  - 10.1007/s10337-013-2391-0
ER  - 

@article{
author = "Malenović, Anđelija and Vemić, Ana and Kostić, Nada and Ivanović, D.",
year = "2013",
abstract = "In this paper, a chemometrically assisted validation of RP-HPLC method, intended for the quantitative analysis of cefuroxime axetil (A and B), cefuroxime acid, cefuroxime lactone, cefuroxime axetil sulfoxide (A and B), a dagger(3)-cefuroxime axetil and anti cefuroxime axetil (A and B) in tablets, is presented. Since the successful separation could be achieved with the mobile phase containing only methanol and water, Luna C18 column was selected for the analysis. Under these circumstances, the optimization was quite straightforward and included only a fine tuning of the chromatographic conditions to reduce total run time and maintain the achieved separation. The established method was then subjected to the method validation and the required validation parameters were tested. For the robustness evaluation, a fractional factorial 2(4-1) design was utilized and factors that might significantly affect the system performance were defined. For the significant factors, the non-significant intervals were determined and the acceptable system suitability limit for resolution factor between cefuroxime axetil A and cefuroxime axetil a dagger(3) isomer (R (2)) was calculated. As the other validation parameters were also found to be suitable, the possibility to apply the proposed method for the determination of cefuroxime axetil, cefuroxime acid, cefuroxime lactone, cefuroxime axetil sulfoxide, a dagger(3)-cefuroxime axetil and anti cefuroxime axetil in any laboratory under different circumstances is proven.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Chromatographia",
title = "Evaluation of RP-HPLC Method Intended for the Analysis of Cefuroxime Axetil and ITS Impurities Supported by Experimental Design",
volume = "76",
number = "5-6",
pages = "293-298",
doi = "10.1007/s10337-013-2391-0"
}

Malenović, A., Vemić, A., Kostić, N.,& Ivanović, D.. (2013). Evaluation of RP-HPLC Method Intended for the Analysis of Cefuroxime Axetil and ITS Impurities Supported by Experimental Design. in Chromatographia
Springer Heidelberg, Heidelberg., 76(5-6), 293-298.
https://doi.org/10.1007/s10337-013-2391-0

Malenović A, Vemić A, Kostić N, Ivanović D. Evaluation of RP-HPLC Method Intended for the Analysis of Cefuroxime Axetil and ITS Impurities Supported by Experimental Design. in Chromatographia. 2013;76(5-6):293-298.
doi:10.1007/s10337-013-2391-0 .

Malenović, Anđelija, Vemić, Ana, Kostić, Nada, Ivanović, D., "Evaluation of RP-HPLC Method Intended for the Analysis of Cefuroxime Axetil and ITS Impurities Supported by Experimental Design" in Chromatographia, 76, no. 5-6 (2013):293-298,
https://doi.org/10.1007/s10337-013-2391-0 . .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Vemić, Ana
AU  - Rakić, Tijana
AU  - Kostić, Nađa M.
AU  - Malenović, Anđelija
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1766
AB  - Modern trends in drug quality control are moving toward incorporating quality into the method during its development. That course is in accordance with Quality by Design (QbD) concept defined by ICH Q 8 (R2) guideline. This implies that the method development begins by defining the method goals and collecting the relevant data, i.e., analyzing the properties of a given active pharmaceutical ingredient and evaluating the optimal experimental conditions. It is followed by a risk assessment defined by systematic robustness testing with the application of experimental design, while the final confirmation of the method reliability is done through the complete validation tests. In this paper, development of Karl Fischer titration for water determination in active pharmaceutical substance clindamycin phosphate is presented. Karl Fischer titration (KFT) is a widely used method in the pharmaceutical industry for determination of water content. For the analyzed substance, the European Pharmacopoeia suggests a relatively large amount of samples for the determination of water, so the objective of this study is to confirm the applicability of the developed method for the determination of water in small amount of samples applying QbD approach. According to QbD rules, detail development of coulometric Karl Fischer titration for water determination in clindamycin phosphate was done. For robustness testing, fractional factorial design 24-1 was successful applied and confirmed that the method was robust. Robustness was evaluated using statistical and graphical methods. Also, design space was defined so the region in which factors could be changed without significant changes in water content was defined. At the end, other validation parameters were determined and it was proven that the analytical test system was capable of providing useful and valid analytical data.
AB  - Savremeni zahtevi u industriji, posebno farmaceutskoj, postavljeni su na konceptu ugrađivanja kvaliteta u metodu tokom njenog razvoja (eng. Quality by Design - QbD koncept). Ovo podrazumeva da razvoj metode započinje definisanjem cilja metode i prikupljanjem odgovarajućih podataka, nastavlja se procenom rizika, a konačna potvrda pouzdanosti metode dobija se njenom validacijom. Ovakav pristup uspešno je primenjen na metodi Karl Fišer-ove titracije za određivanje sadržaja vode u klindamicin-fosfatu. Dobijeni rezultati su u skladu sa postavljenim QbD konceptom i predstavljaju značajan napredak u primeni metode titracije po Karl Fišer-u u farmaceutskoj industriji.
PB  - Savez hemijskih inženjera, Beograd
T2  - Hemijska industrija
T1  - Development of Karl Fischer titration method using Duality by Design concept
T1  - Razvoj metode titracije po Karl Fišeru primenom tzv. Quality by Design koncepta
VL  - 66
IS  - 5
SP  - 659
EP  - 665
DO  - 10.2298/HEMIND120120030J
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Vemić, Ana and Rakić, Tijana and Kostić, Nađa M. and Malenović, Anđelija",
year = "2012",
abstract = "Modern trends in drug quality control are moving toward incorporating quality into the method during its development. That course is in accordance with Quality by Design (QbD) concept defined by ICH Q 8 (R2) guideline. This implies that the method development begins by defining the method goals and collecting the relevant data, i.e., analyzing the properties of a given active pharmaceutical ingredient and evaluating the optimal experimental conditions. It is followed by a risk assessment defined by systematic robustness testing with the application of experimental design, while the final confirmation of the method reliability is done through the complete validation tests. In this paper, development of Karl Fischer titration for water determination in active pharmaceutical substance clindamycin phosphate is presented. Karl Fischer titration (KFT) is a widely used method in the pharmaceutical industry for determination of water content. For the analyzed substance, the European Pharmacopoeia suggests a relatively large amount of samples for the determination of water, so the objective of this study is to confirm the applicability of the developed method for the determination of water in small amount of samples applying QbD approach. According to QbD rules, detail development of coulometric Karl Fischer titration for water determination in clindamycin phosphate was done. For robustness testing, fractional factorial design 24-1 was successful applied and confirmed that the method was robust. Robustness was evaluated using statistical and graphical methods. Also, design space was defined so the region in which factors could be changed without significant changes in water content was defined. At the end, other validation parameters were determined and it was proven that the analytical test system was capable of providing useful and valid analytical data., Savremeni zahtevi u industriji, posebno farmaceutskoj, postavljeni su na konceptu ugrađivanja kvaliteta u metodu tokom njenog razvoja (eng. Quality by Design - QbD koncept). Ovo podrazumeva da razvoj metode započinje definisanjem cilja metode i prikupljanjem odgovarajućih podataka, nastavlja se procenom rizika, a konačna potvrda pouzdanosti metode dobija se njenom validacijom. Ovakav pristup uspešno je primenjen na metodi Karl Fišer-ove titracije za određivanje sadržaja vode u klindamicin-fosfatu. Dobijeni rezultati su u skladu sa postavljenim QbD konceptom i predstavljaju značajan napredak u primeni metode titracije po Karl Fišer-u u farmaceutskoj industriji.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Hemijska industrija",
title = "Development of Karl Fischer titration method using Duality by Design concept, Razvoj metode titracije po Karl Fišeru primenom tzv. Quality by Design koncepta",
volume = "66",
number = "5",
pages = "659-665",
doi = "10.2298/HEMIND120120030J"
}

Jančić-Stojanović, B., Vemić, A., Rakić, T., Kostić, N. M.,& Malenović, A.. (2012). Development of Karl Fischer titration method using Duality by Design concept. in Hemijska industrija
Savez hemijskih inženjera, Beograd., 66(5), 659-665.
https://doi.org/10.2298/HEMIND120120030J

Jančić-Stojanović B, Vemić A, Rakić T, Kostić NM, Malenović A. Development of Karl Fischer titration method using Duality by Design concept. in Hemijska industrija. 2012;66(5):659-665.
doi:10.2298/HEMIND120120030J .

Jančić-Stojanović, Biljana, Vemić, Ana, Rakić, Tijana, Kostić, Nađa M., Malenović, Anđelija, "Development of Karl Fischer titration method using Duality by Design concept" in Hemijska industrija, 66, no. 5 (2012):659-665,
https://doi.org/10.2298/HEMIND120120030J . .

TY  - JOUR
AU  - Vemić, Ana
AU  - Malenović, Anđelija
AU  - Rakić, Tijana
AU  - Kostić, Nada M.
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1681
AB  - Microemulsions when used as mobile phases represent a very powerful chromatographic tool due to their polyphase structure. The aim of this study was to investigate the influence of the mobile phase composition and resulting microemulsion droplet's properties, as well as the stationary phase lipophilicity on the chromatographic behavior of pramipexole and its five impurities. Investigation was carried out according to the experimental plan defined by a full factorial design 2(4) with four central point replications. While the most affected by column characteristics was the last eluting, most lipophilic substance, the composition and characteristics of microemulsion droplets were equally important, so the partition system microemulsion droplets/stationary phase proved to be the most significant. Stationary phase lipophilicity did not affect the most hydrophilic component and only the partition system microemulsion droplets/bulk of the eluent impacted its behavior. For the separation of the critical pair, almost equal effects of the microemulsion droplets/stationary phase and bulk of the eluent/stationary phase partition systems were noted.
PB  - Soc Brasileira Quimica, Sao Paulo
T2  - Journal of the Brazilian Chemical Society
T1  - Physicochemical Factors Governing the Partition of Pramipexole and Its Five Impurities in Microemulsion Liquid Chromatographic Systems
VL  - 23
IS  - 11
SP  - 2084
EP  - 2092
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1681
ER  - 

@article{
author = "Vemić, Ana and Malenović, Anđelija and Rakić, Tijana and Kostić, Nada M. and Jančić-Stojanović, Biljana and Ivanović, Darko and Medenica, Mirjana",
year = "2012",
abstract = "Microemulsions when used as mobile phases represent a very powerful chromatographic tool due to their polyphase structure. The aim of this study was to investigate the influence of the mobile phase composition and resulting microemulsion droplet's properties, as well as the stationary phase lipophilicity on the chromatographic behavior of pramipexole and its five impurities. Investigation was carried out according to the experimental plan defined by a full factorial design 2(4) with four central point replications. While the most affected by column characteristics was the last eluting, most lipophilic substance, the composition and characteristics of microemulsion droplets were equally important, so the partition system microemulsion droplets/stationary phase proved to be the most significant. Stationary phase lipophilicity did not affect the most hydrophilic component and only the partition system microemulsion droplets/bulk of the eluent impacted its behavior. For the separation of the critical pair, almost equal effects of the microemulsion droplets/stationary phase and bulk of the eluent/stationary phase partition systems were noted.",
publisher = "Soc Brasileira Quimica, Sao Paulo",
journal = "Journal of the Brazilian Chemical Society",
title = "Physicochemical Factors Governing the Partition of Pramipexole and Its Five Impurities in Microemulsion Liquid Chromatographic Systems",
volume = "23",
number = "11",
pages = "2084-2092",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1681"
}

Vemić, A., Malenović, A., Rakić, T., Kostić, N. M., Jančić-Stojanović, B., Ivanović, D.,& Medenica, M.. (2012). Physicochemical Factors Governing the Partition of Pramipexole and Its Five Impurities in Microemulsion Liquid Chromatographic Systems. in Journal of the Brazilian Chemical Society
Soc Brasileira Quimica, Sao Paulo., 23(11), 2084-2092.
https://hdl.handle.net/21.15107/rcub_farfar_1681

Vemić A, Malenović A, Rakić T, Kostić NM, Jančić-Stojanović B, Ivanović D, Medenica M. Physicochemical Factors Governing the Partition of Pramipexole and Its Five Impurities in Microemulsion Liquid Chromatographic Systems. in Journal of the Brazilian Chemical Society. 2012;23(11):2084-2092.
https://hdl.handle.net/21.15107/rcub_farfar_1681 .

Vemić, Ana, Malenović, Anđelija, Rakić, Tijana, Kostić, Nada M., Jančić-Stojanović, Biljana, Ivanović, Darko, Medenica, Mirjana, "Physicochemical Factors Governing the Partition of Pramipexole and Its Five Impurities in Microemulsion Liquid Chromatographic Systems" in Journal of the Brazilian Chemical Society, 23, no. 11 (2012):2084-2092,
https://hdl.handle.net/21.15107/rcub_farfar_1681 .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Kostić, Nađa
AU  - Vemić, Ana
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1793
AB  - In the current paper, multi-criteria decision making (MCDM) approach was applied to optimize micellar liquid chromatography (MLC) intended for the pharmaceutical analysis of atorvastatin and its impurities, trans-atorvastatin and desfluoro-atorvastatin. MLC is a reversedphase liquid chromatographic (RPLC) mode where the modification of mobile phase leads to the stationary phase modification. This results in the diverse interactions (hydrophobic, ionic and steric) significantly affecting retention and selectivity. For that reason double chained surfactant sodium dioctyl sulfosuccinate - AOT (Aerosol OT), with oxygen atoms in its tails, was used for the first time in such kind of separation. As the most efficient way to investigate a high number of factors, and simultaneously optimize defined antagonistic objectives (minimization of run time and maximization of atorvastatin and trans-atorvastatin resolution) MCDM approach was employed. Central composite design (CCD) with fractional factorial design, ± 0.5 star design and four replications in central point was used to define plan of experiments. Five responses selected during method development were optimized simultaneously using Derringer's desirability function. The predicted optimum was: 32 % acetonitrile, 2 % ethylene glycol, 66 % 6.4 mmol L-1 AOT in 20 mmol L-1 ammonium acetate, pH of the water phase 5.50 adjusted with acetic acid, flow rate 1.15 mL min-1 and column temperature of 10C.
AB  - U ovom radu, za optimizaciju metode micelarne tečne hromatografije (MLC) namenjene za farmaceutsku analizu atorvastatina i njegovih nečistoća, trans-atorvastatina i desfluoroatorvastatina primenjen je multikriterijumski pristup. MLC je oblik reverzno-fazne tečne hromatografije gde promene u mobilnoj fazi dovode i do modifikacije stacionarne faze. Ovo rezultuje različitim interakcijama (hidrofobnim, jonskim, sternim) sa značajnim uticajem na retenciju i selektivnost. Zbog toga je za separaciju odabran surfaktant koji sadrži dvostruki lanac i atom kiseonika, natrijum dioktil sulfosukcinat - AOT (Aerosol OT). Kao najefikasniji način za istraživanje velikog broja faktora i istovremenu optimizaciju suprotstavljenih ciljeva (minimizacija vremena trajanja razdvajanja i maksimizacija rezolucije između atorvastatina i trans-atorvastatina) primenjena je multikriterijumska optimizacija. Centralni kompozicioni dizajn (CCD) sa frakcionim faktorskim dizajnom, ± 0.5 zvezda dizajnom i četiri replikacije u centralnoj tački korišćen je za definisanje plana eksperimenta. Korišćenjem Derringer funkcije poželjnih odgovora, optimizirano je pet odgovora. Predviđeni optimalni uslovi bili su: 32 % acetonitrila, 2 % etilen-glikola, 66 % 6,4 mmol L-1 AOT u 20 mmol L-1 amonijum-acetatu, pH vodene faze 5,50 podešen sirćetnom kiselinom, protok 1,15 mL min-1 uz temperaturu kolone 10 C.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Multi-criteria decision making approach for the optimization of atorvastatin and its impurities separation by micellar liquid chromatography
T1  - Multikriterijumski pristup optimizaciji metode micelarne tečne hromatografije za analizu atorvastatina i njegovih nečistoća
VL  - 62
IS  - 3
SP  - 191
EP  - 207
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1793
ER  - 

@article{
author = "Malenović, Anđelija and Kostić, Nađa and Vemić, Ana and Rakić, Tijana and Jančić-Stojanović, Biljana",
year = "2012",
abstract = "In the current paper, multi-criteria decision making (MCDM) approach was applied to optimize micellar liquid chromatography (MLC) intended for the pharmaceutical analysis of atorvastatin and its impurities, trans-atorvastatin and desfluoro-atorvastatin. MLC is a reversedphase liquid chromatographic (RPLC) mode where the modification of mobile phase leads to the stationary phase modification. This results in the diverse interactions (hydrophobic, ionic and steric) significantly affecting retention and selectivity. For that reason double chained surfactant sodium dioctyl sulfosuccinate - AOT (Aerosol OT), with oxygen atoms in its tails, was used for the first time in such kind of separation. As the most efficient way to investigate a high number of factors, and simultaneously optimize defined antagonistic objectives (minimization of run time and maximization of atorvastatin and trans-atorvastatin resolution) MCDM approach was employed. Central composite design (CCD) with fractional factorial design, ± 0.5 star design and four replications in central point was used to define plan of experiments. Five responses selected during method development were optimized simultaneously using Derringer's desirability function. The predicted optimum was: 32 % acetonitrile, 2 % ethylene glycol, 66 % 6.4 mmol L-1 AOT in 20 mmol L-1 ammonium acetate, pH of the water phase 5.50 adjusted with acetic acid, flow rate 1.15 mL min-1 and column temperature of 10C., U ovom radu, za optimizaciju metode micelarne tečne hromatografije (MLC) namenjene za farmaceutsku analizu atorvastatina i njegovih nečistoća, trans-atorvastatina i desfluoroatorvastatina primenjen je multikriterijumski pristup. MLC je oblik reverzno-fazne tečne hromatografije gde promene u mobilnoj fazi dovode i do modifikacije stacionarne faze. Ovo rezultuje različitim interakcijama (hidrofobnim, jonskim, sternim) sa značajnim uticajem na retenciju i selektivnost. Zbog toga je za separaciju odabran surfaktant koji sadrži dvostruki lanac i atom kiseonika, natrijum dioktil sulfosukcinat - AOT (Aerosol OT). Kao najefikasniji način za istraživanje velikog broja faktora i istovremenu optimizaciju suprotstavljenih ciljeva (minimizacija vremena trajanja razdvajanja i maksimizacija rezolucije između atorvastatina i trans-atorvastatina) primenjena je multikriterijumska optimizacija. Centralni kompozicioni dizajn (CCD) sa frakcionim faktorskim dizajnom, ± 0.5 zvezda dizajnom i četiri replikacije u centralnoj tački korišćen je za definisanje plana eksperimenta. Korišćenjem Derringer funkcije poželjnih odgovora, optimizirano je pet odgovora. Predviđeni optimalni uslovi bili su: 32 % acetonitrila, 2 % etilen-glikola, 66 % 6,4 mmol L-1 AOT u 20 mmol L-1 amonijum-acetatu, pH vodene faze 5,50 podešen sirćetnom kiselinom, protok 1,15 mL min-1 uz temperaturu kolone 10 C.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Multi-criteria decision making approach for the optimization of atorvastatin and its impurities separation by micellar liquid chromatography, Multikriterijumski pristup optimizaciji metode micelarne tečne hromatografije za analizu atorvastatina i njegovih nečistoća",
volume = "62",
number = "3",
pages = "191-207",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1793"
}

Malenović, A., Kostić, N., Vemić, A., Rakić, T.,& Jančić-Stojanović, B.. (2012). Multi-criteria decision making approach for the optimization of atorvastatin and its impurities separation by micellar liquid chromatography. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 62(3), 191-207.
https://hdl.handle.net/21.15107/rcub_farfar_1793

Malenović A, Kostić N, Vemić A, Rakić T, Jančić-Stojanović B. Multi-criteria decision making approach for the optimization of atorvastatin and its impurities separation by micellar liquid chromatography. in Arhiv za farmaciju. 2012;62(3):191-207.
https://hdl.handle.net/21.15107/rcub_farfar_1793 .

Malenović, Anđelija, Kostić, Nađa, Vemić, Ana, Rakić, Tijana, Jančić-Stojanović, Biljana, "Multi-criteria decision making approach for the optimization of atorvastatin and its impurities separation by micellar liquid chromatography" in Arhiv za farmaciju, 62, no. 3 (2012):191-207,
https://hdl.handle.net/21.15107/rcub_farfar_1793 .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Jovanović, Marko
AU  - Petrović, Sonja
AU  - Kostić, Nada
AU  - Vemić, Ana
AU  - Jančić-Stojanović, Biljana
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1749
AB  - In this article, the multiobjective optimization of reversed-phase high-performance liquid chromatography (RP-HPLC) method for the analysis of folic acid and its two impurities, p-aminobenzoic acid and N-(4-aminobenzoyl)-L-glutamic acid, is presented. During the preliminary study, the independent variables whose impact should be further examined in the optimization were defined (acetonitrile content in the mobile phase, molarity of sodium 1-heptanesulfonate in the aqueous phase, and pH of the aqueous phase). The face-centered central composite design was chosen for the method optimization. As the dependent variables, the separation between the impurities and the retention factor of folic acid were followed. The analysis of variance (ANOVA) test was done, and good correlation among results was confirmed. For the more accurate and reliable optimization, Derringer's desirability function was applied. On the basis of restrictions adopted for the selected targets, the resulting optimal composition of the mobile phase was acetonitrile -3 mM sodium 1-heptanesulfonate (5.3:94.7 V/V), pH of the aqueous phase adjusted to 2.1 with the concentrated ortho-phosphoric acid. Furthermore, the method was subjected to method validation. It proved to be reliable and suitable for the routine analysis of investigated substances in active pharmaceutical ingredients, as well as in pharmaceutical preparations.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Instrumentation Science & Technology
T1  - Optimization of liquid chromatographic method for the separation of folic acid and its two impurities
VL  - 40
IS  - 2-3
SP  - 138
EP  - 149
DO  - 10.1080/10739149.2011.651670
ER  - 

@article{
author = "Malenović, Anđelija and Jovanović, Marko and Petrović, Sonja and Kostić, Nada and Vemić, Ana and Jančić-Stojanović, Biljana",
year = "2012",
abstract = "In this article, the multiobjective optimization of reversed-phase high-performance liquid chromatography (RP-HPLC) method for the analysis of folic acid and its two impurities, p-aminobenzoic acid and N-(4-aminobenzoyl)-L-glutamic acid, is presented. During the preliminary study, the independent variables whose impact should be further examined in the optimization were defined (acetonitrile content in the mobile phase, molarity of sodium 1-heptanesulfonate in the aqueous phase, and pH of the aqueous phase). The face-centered central composite design was chosen for the method optimization. As the dependent variables, the separation between the impurities and the retention factor of folic acid were followed. The analysis of variance (ANOVA) test was done, and good correlation among results was confirmed. For the more accurate and reliable optimization, Derringer's desirability function was applied. On the basis of restrictions adopted for the selected targets, the resulting optimal composition of the mobile phase was acetonitrile -3 mM sodium 1-heptanesulfonate (5.3:94.7 V/V), pH of the aqueous phase adjusted to 2.1 with the concentrated ortho-phosphoric acid. Furthermore, the method was subjected to method validation. It proved to be reliable and suitable for the routine analysis of investigated substances in active pharmaceutical ingredients, as well as in pharmaceutical preparations.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Instrumentation Science & Technology",
title = "Optimization of liquid chromatographic method for the separation of folic acid and its two impurities",
volume = "40",
number = "2-3",
pages = "138-149",
doi = "10.1080/10739149.2011.651670"
}

Malenović, A., Jovanović, M., Petrović, S., Kostić, N., Vemić, A.,& Jančić-Stojanović, B.. (2012). Optimization of liquid chromatographic method for the separation of folic acid and its two impurities. in Instrumentation Science & Technology
Taylor & Francis Inc, Philadelphia., 40(2-3), 138-149.
https://doi.org/10.1080/10739149.2011.651670

Malenović A, Jovanović M, Petrović S, Kostić N, Vemić A, Jančić-Stojanović B. Optimization of liquid chromatographic method for the separation of folic acid and its two impurities. in Instrumentation Science & Technology. 2012;40(2-3):138-149.
doi:10.1080/10739149.2011.651670 .

Malenović, Anđelija, Jovanović, Marko, Petrović, Sonja, Kostić, Nada, Vemić, Ana, Jančić-Stojanović, Biljana, "Optimization of liquid chromatographic method for the separation of folic acid and its two impurities" in Instrumentation Science & Technology, 40, no. 2-3 (2012):138-149,
https://doi.org/10.1080/10739149.2011.651670 . .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Rakić, Tijana
AU  - Kostić, Nada
AU  - Vemić, Ana
AU  - Malenović, Anđelija
AU  - Ivanović, D.
AU  - Medenica, Mirjana
PY  - 2011
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1477
AB  - In this paper a new chromatographic response function (CRF) is designed and proposed for utilization in the optimization strategies. The function capability to represent the overall quality of a experimentally obtained chromatograms was compared to the other two objective functions and proved to give more accurate and reliable results. The new CRF has improved concept of separation and time term estimation. It reflects all important defects of the chromatogram such as the appearance of asymmetrical or overlapping peaks and prolonged elution time and allows the appropriate weighting of each of them. The LC separation of raloxifene and its four impurities was evaluated through the central composite design experimental plan choosing the new CRF to be the only output of the system. The function demonstrated the ability to judge the impact of the complex interactions of the selected chromatographic parameters (acetonitrile content in the mobile phase, sodium dodecyl sulfate concentration in the water phase, pH of the mobile phase and column temperature) on the mixture behavior and led to the determination of the optimal separation conditions. The newly developed CRF proved to have the advanced performances and it presents the important step forward in the optimization of the chromatographic separation.
PB  - Elsevier Science BV, Amsterdam
T2  - Talanta
T1  - Advancement in optimization tactic achieved by newly developed chromatographic response function: Application to LC separation of raloxifene and its impurities
VL  - 85
IS  - 3
SP  - 1453
EP  - 1460
DO  - 10.1016/j.talanta.2011.06.029
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Rakić, Tijana and Kostić, Nada and Vemić, Ana and Malenović, Anđelija and Ivanović, D. and Medenica, Mirjana",
year = "2011",
abstract = "In this paper a new chromatographic response function (CRF) is designed and proposed for utilization in the optimization strategies. The function capability to represent the overall quality of a experimentally obtained chromatograms was compared to the other two objective functions and proved to give more accurate and reliable results. The new CRF has improved concept of separation and time term estimation. It reflects all important defects of the chromatogram such as the appearance of asymmetrical or overlapping peaks and prolonged elution time and allows the appropriate weighting of each of them. The LC separation of raloxifene and its four impurities was evaluated through the central composite design experimental plan choosing the new CRF to be the only output of the system. The function demonstrated the ability to judge the impact of the complex interactions of the selected chromatographic parameters (acetonitrile content in the mobile phase, sodium dodecyl sulfate concentration in the water phase, pH of the mobile phase and column temperature) on the mixture behavior and led to the determination of the optimal separation conditions. The newly developed CRF proved to have the advanced performances and it presents the important step forward in the optimization of the chromatographic separation.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Talanta",
title = "Advancement in optimization tactic achieved by newly developed chromatographic response function: Application to LC separation of raloxifene and its impurities",
volume = "85",
number = "3",
pages = "1453-1460",
doi = "10.1016/j.talanta.2011.06.029"
}

Jančić-Stojanović, B., Rakić, T., Kostić, N., Vemić, A., Malenović, A., Ivanović, D.,& Medenica, M.. (2011). Advancement in optimization tactic achieved by newly developed chromatographic response function: Application to LC separation of raloxifene and its impurities. in Talanta
Elsevier Science BV, Amsterdam., 85(3), 1453-1460.
https://doi.org/10.1016/j.talanta.2011.06.029

Jančić-Stojanović B, Rakić T, Kostić N, Vemić A, Malenović A, Ivanović D, Medenica M. Advancement in optimization tactic achieved by newly developed chromatographic response function: Application to LC separation of raloxifene and its impurities. in Talanta. 2011;85(3):1453-1460.
doi:10.1016/j.talanta.2011.06.029 .

Jančić-Stojanović, Biljana, Rakić, Tijana, Kostić, Nada, Vemić, Ana, Malenović, Anđelija, Ivanović, D., Medenica, Mirjana, "Advancement in optimization tactic achieved by newly developed chromatographic response function: Application to LC separation of raloxifene and its impurities" in Talanta, 85, no. 3 (2011):1453-1460,
https://doi.org/10.1016/j.talanta.2011.06.029 . .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Jančić-Stojanović, Biljana
AU  - Vemić, Ana
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2010
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1346
AB  - In this paper, a previously optimized method for HPLC analysis of pramipexole and its impurities was subjected to method validation in accordance with official regulations. The optimized chromatographic conditions were as follows: mobile phase acetonitrile water phase [15 + 85, v/v, water phase contained 1% triethylamine (TEA), pH adjusted to 7.0 with orthophosphoric acid]; detection at 262 nm for pramipexole, BI-II 751 xx, BI-II 786 BS, BI-II 820 BS, and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL; column temperature, 25 degrees C; and flow rate, 1 mL/min. Acetonitrile and TEA content, pH of the water phase, flow rate, column temperature, and column type were factors studied in robustness testing. According to the experimental plan defined by a Plackett-Burman design, five dummy variables were added in order to have 12 factors. As output, resolution factor was chosen. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. Also, nonsignificance intervals for significant factors were estimated, and limits for the system suitability test were determined. Finally, linearity, accuracy, and precision of the proposed HPLC method were defined. LOD and LOQ values for analyzed impurities were determined. The method was completely defined by these experiments.
PB  - AOAC Int, Gaithersburg
T2  - Journal of AOAC International
T1  - Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities
VL  - 93
IS  - 4
SP  - 1102
EP  - 1112
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1346
ER  - 

@article{
author = "Malenović, Anđelija and Jančić-Stojanović, Biljana and Vemić, Ana and Ivanović, Darko and Medenica, Mirjana",
year = "2010",
abstract = "In this paper, a previously optimized method for HPLC analysis of pramipexole and its impurities was subjected to method validation in accordance with official regulations. The optimized chromatographic conditions were as follows: mobile phase acetonitrile water phase [15 + 85, v/v, water phase contained 1% triethylamine (TEA), pH adjusted to 7.0 with orthophosphoric acid]; detection at 262 nm for pramipexole, BI-II 751 xx, BI-II 786 BS, BI-II 820 BS, and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL; column temperature, 25 degrees C; and flow rate, 1 mL/min. Acetonitrile and TEA content, pH of the water phase, flow rate, column temperature, and column type were factors studied in robustness testing. According to the experimental plan defined by a Plackett-Burman design, five dummy variables were added in order to have 12 factors. As output, resolution factor was chosen. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. Also, nonsignificance intervals for significant factors were estimated, and limits for the system suitability test were determined. Finally, linearity, accuracy, and precision of the proposed HPLC method were defined. LOD and LOQ values for analyzed impurities were determined. The method was completely defined by these experiments.",
publisher = "AOAC Int, Gaithersburg",
journal = "Journal of AOAC International",
title = "Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities",
volume = "93",
number = "4",
pages = "1102-1112",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1346"
}

Malenović, A., Jančić-Stojanović, B., Vemić, A., Ivanović, D.,& Medenica, M.. (2010). Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities. in Journal of AOAC International
AOAC Int, Gaithersburg., 93(4), 1102-1112.
https://hdl.handle.net/21.15107/rcub_farfar_1346

Malenović A, Jančić-Stojanović B, Vemić A, Ivanović D, Medenica M. Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities. in Journal of AOAC International. 2010;93(4):1102-1112.
https://hdl.handle.net/21.15107/rcub_farfar_1346 .

Malenović, Anđelija, Jančić-Stojanović, Biljana, Vemić, Ana, Ivanović, Darko, Medenica, Mirjana, "Validation of a Column Liquid Chromatographic Method for the Analysis of Pramipexole and Its Five Impurities" in Journal of AOAC International, 93, no. 4 (2010):1102-1112,
https://hdl.handle.net/21.15107/rcub_farfar_1346 .