TY  - JOUR
AU  - Maksić, Jelena
AU  - Tumpa, Anja
AU  - Stajić, Ana
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
PY  - 2016
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2604
AB  - In this paper separation of granisetron and its two related substances in HILIC mode is presented. Separation was done on silica column derivatized with sulfoalkylbetaine groups (ZIC-HILIC). Firstly, retention mechanisms were assessed whereby retention factors of substances were followed in wide range of acetonitrile content (80-97%), at constant concentration of aqueous buffer (10 mM) as well as at constant pH value of 3.0. Further, in order to developed optimal HILIC method, Design of Experiments (DoE) methodology was applied. For optimization full factorial design 32 was employed. Influence of acetonitrile content and ammonium acetate concentration were investigated while pH of the water phase was kept at 3.3. Adequacy of obtained mathematical models was confirmed by ANOVA. Optimization goals (alpha > 1.15 and minimal run time) were accomplished with 94.7% of acetonitrile in mobile phase and 70 mM of ammonium acetate in water phase. Optimal point was in the middle of defined Design Space. In the next phase, robustness was experimetally tested by Rechtschaffen design. The investigated factors and their levels were: acetonitrile content (+/- 1%), ammonium acetate molarity in water phase (+/- 2 mM), pH value of water phase (+/- 0.2) and column temperature (+/- 4 degrees C). The validation scope included selectivity, linearity, accuracy and precision as well as determination of limit of detection (LOD) and limit of quantification (LOQ) for the related substances. Additionally, the validation acceptance criteria were met in all cases. Finally, the proposed method could be successfully utilized for estimation of granisetron HCl and its related substances in tablets and parenteral dosage forms, as well as for monitoring degradation under various stress conditions.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Hydrophilic interaction liquid chromatography in analysis of granisetron HCl and its related substances. Retention mechanisms and method development
VL  - 123
SP  - 93
EP  - 103
DO  - 10.1016/j.jpba.2016.02.010
ER  - 

@article{
author = "Maksić, Jelena and Tumpa, Anja and Stajić, Ana and Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana",
year = "2016",
abstract = "In this paper separation of granisetron and its two related substances in HILIC mode is presented. Separation was done on silica column derivatized with sulfoalkylbetaine groups (ZIC-HILIC). Firstly, retention mechanisms were assessed whereby retention factors of substances were followed in wide range of acetonitrile content (80-97%), at constant concentration of aqueous buffer (10 mM) as well as at constant pH value of 3.0. Further, in order to developed optimal HILIC method, Design of Experiments (DoE) methodology was applied. For optimization full factorial design 32 was employed. Influence of acetonitrile content and ammonium acetate concentration were investigated while pH of the water phase was kept at 3.3. Adequacy of obtained mathematical models was confirmed by ANOVA. Optimization goals (alpha > 1.15 and minimal run time) were accomplished with 94.7% of acetonitrile in mobile phase and 70 mM of ammonium acetate in water phase. Optimal point was in the middle of defined Design Space. In the next phase, robustness was experimetally tested by Rechtschaffen design. The investigated factors and their levels were: acetonitrile content (+/- 1%), ammonium acetate molarity in water phase (+/- 2 mM), pH value of water phase (+/- 0.2) and column temperature (+/- 4 degrees C). The validation scope included selectivity, linearity, accuracy and precision as well as determination of limit of detection (LOD) and limit of quantification (LOQ) for the related substances. Additionally, the validation acceptance criteria were met in all cases. Finally, the proposed method could be successfully utilized for estimation of granisetron HCl and its related substances in tablets and parenteral dosage forms, as well as for monitoring degradation under various stress conditions.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Hydrophilic interaction liquid chromatography in analysis of granisetron HCl and its related substances. Retention mechanisms and method development",
volume = "123",
pages = "93-103",
doi = "10.1016/j.jpba.2016.02.010"
}

Maksić, J., Tumpa, A., Stajić, A., Jovanović, M., Rakić, T.,& Jančić-Stojanović, B.. (2016). Hydrophilic interaction liquid chromatography in analysis of granisetron HCl and its related substances. Retention mechanisms and method development. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 123, 93-103.
https://doi.org/10.1016/j.jpba.2016.02.010

Maksić J, Tumpa A, Stajić A, Jovanović M, Rakić T, Jančić-Stojanović B. Hydrophilic interaction liquid chromatography in analysis of granisetron HCl and its related substances. Retention mechanisms and method development. in Journal of Pharmaceutical and Biomedical Analysis. 2016;123:93-103.
doi:10.1016/j.jpba.2016.02.010 .

Maksić, Jelena, Tumpa, Anja, Stajić, Ana, Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, "Hydrophilic interaction liquid chromatography in analysis of granisetron HCl and its related substances. Retention mechanisms and method development" in Journal of Pharmaceutical and Biomedical Analysis, 123 (2016):93-103,
https://doi.org/10.1016/j.jpba.2016.02.010 . .

TY  - JOUR
AU  - Tumpa, Anja
AU  - Rakić, Tijana
AU  - Jovanović, Marko
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2332
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3443
AB  - The retention behavior of substances in hydrophilic interaction liquid chromatography (HILIC) is difficult to predict. Mixture investigated in this paper consists of acetylsalicylic acid, amlodipine, impurity A of amlodipine, and atenolol, a very often used combination in treatment of some cardiovascular diseases. Retention behavior dependence on the most influential chromatographic factors is described by mathematical models, with the special emphasis on pH of the mobile phase. D-optimal design is applied to generate more complex models and to obtain more accurate results. Comparison of Predicted R-2 values of quadratic and cubic model for pH dependence (0.847 and 0.934, respectively) shows that the cubic model has significantly better prediction ability than quadratic in the investigated system. After describing retention behavior, chemometrical tools (indirect modeling of complex chromatographic responses and grid point search optimization) are used to locate the optimal conditions for analyzed mixture in terms of satisfactory separation and minimal analysis duration. The optimal conditions are Column: Kinetex HILIC 100 A (100mmx4.5mm, 2.6 mu m particle size); injection volume: 5 mu L; flow rate: 1mLmin(-1); column temperature: 30 degrees C; detection wavelength: 254nm; mobile phase: acetonitrile-water phase (75mM ammonium acetate, pH 5.3) (91:9V/V).
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Liquid Chromatography & Related Technologies
T1  - Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology
VL  - 38
IS  - 16
SP  - 1555
EP  - 1560
DO  - 10.1080/10826076.2015.1077863
ER  - 

@article{
author = "Tumpa, Anja and Rakić, Tijana and Jovanović, Marko and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "The retention behavior of substances in hydrophilic interaction liquid chromatography (HILIC) is difficult to predict. Mixture investigated in this paper consists of acetylsalicylic acid, amlodipine, impurity A of amlodipine, and atenolol, a very often used combination in treatment of some cardiovascular diseases. Retention behavior dependence on the most influential chromatographic factors is described by mathematical models, with the special emphasis on pH of the mobile phase. D-optimal design is applied to generate more complex models and to obtain more accurate results. Comparison of Predicted R-2 values of quadratic and cubic model for pH dependence (0.847 and 0.934, respectively) shows that the cubic model has significantly better prediction ability than quadratic in the investigated system. After describing retention behavior, chemometrical tools (indirect modeling of complex chromatographic responses and grid point search optimization) are used to locate the optimal conditions for analyzed mixture in terms of satisfactory separation and minimal analysis duration. The optimal conditions are Column: Kinetex HILIC 100 A (100mmx4.5mm, 2.6 mu m particle size); injection volume: 5 mu L; flow rate: 1mLmin(-1); column temperature: 30 degrees C; detection wavelength: 254nm; mobile phase: acetonitrile-water phase (75mM ammonium acetate, pH 5.3) (91:9V/V).",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Liquid Chromatography & Related Technologies",
title = "Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology",
volume = "38",
number = "16",
pages = "1555-1560",
doi = "10.1080/10826076.2015.1077863"
}

Tumpa, A., Rakić, T., Jovanović, M.,& Jančić-Stojanović, B.. (2015). Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology. in Journal of Liquid Chromatography & Related Technologies
Taylor & Francis Inc, Philadelphia., 38(16), 1555-1560.
https://doi.org/10.1080/10826076.2015.1077863

Tumpa A, Rakić T, Jovanović M, Jančić-Stojanović B. Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology. in Journal of Liquid Chromatography & Related Technologies. 2015;38(16):1555-1560.
doi:10.1080/10826076.2015.1077863 .

Tumpa, Anja, Rakić, Tijana, Jovanović, Marko, Jančić-Stojanović, Biljana, "Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology" in Journal of Liquid Chromatography & Related Technologies, 38, no. 16 (2015):1555-1560,
https://doi.org/10.1080/10826076.2015.1077863 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Tumpa, Anja
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3418
AB  - This study presents the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol, its endo-isomer and three impurities following Quality by Design (QbD) approach. The main objective of the method was to identify the conditions where adequate separation quality in minimal analysis duration could be achieved within a robust region that guarantees the stability of method performance. The relationship between critical process parameters (acetonitrile content in the mobile phase, pH of the water phase and ammonium acetate concentration in the water phase) and critical quality attributes is created applying design of experiments methodology. The defined mathematical models and Monte Carlo simulation are used to evaluate the risk of uncertainty in models prediction and incertitude in adjusting the process parameters and to identify the design space. The borders of the design space are experimentally verified and confirmed that the quality of the method is preserved in this region. Moreover, Plackett-Burman design is applied for experimental robustness testing and method is fully validated to verify the adequacy of selected optimal conditions: the analytical column ZIC HILIC (100 mm x 4.6 mm, 5 mu m particle size); mobile phase consisted of acetonitrile-water phase (72 mM ammonium acetate, pH adjusted to 6.5 with glacial acetic acid) (86.7:13.3) v/v; column temperature 25 degrees C, mobile phase flow rate 1 mL min(-1), wavelength of detection 254 nm.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities
VL  - 110
SP  - 42
EP  - 48
DO  - 10.1016/j.jpba.2015.02.046
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Tumpa, Anja and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "This study presents the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol, its endo-isomer and three impurities following Quality by Design (QbD) approach. The main objective of the method was to identify the conditions where adequate separation quality in minimal analysis duration could be achieved within a robust region that guarantees the stability of method performance. The relationship between critical process parameters (acetonitrile content in the mobile phase, pH of the water phase and ammonium acetate concentration in the water phase) and critical quality attributes is created applying design of experiments methodology. The defined mathematical models and Monte Carlo simulation are used to evaluate the risk of uncertainty in models prediction and incertitude in adjusting the process parameters and to identify the design space. The borders of the design space are experimentally verified and confirmed that the quality of the method is preserved in this region. Moreover, Plackett-Burman design is applied for experimental robustness testing and method is fully validated to verify the adequacy of selected optimal conditions: the analytical column ZIC HILIC (100 mm x 4.6 mm, 5 mu m particle size); mobile phase consisted of acetonitrile-water phase (72 mM ammonium acetate, pH adjusted to 6.5 with glacial acetic acid) (86.7:13.3) v/v; column temperature 25 degrees C, mobile phase flow rate 1 mL min(-1), wavelength of detection 254 nm.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities",
volume = "110",
pages = "42-48",
doi = "10.1016/j.jpba.2015.02.046"
}

Jovanović, M., Rakić, T., Tumpa, A.,& Jančić-Stojanović, B.. (2015). Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 110, 42-48.
https://doi.org/10.1016/j.jpba.2015.02.046

Jovanović M, Rakić T, Tumpa A, Jančić-Stojanović B. Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities. in Journal of Pharmaceutical and Biomedical Analysis. 2015;110:42-48.
doi:10.1016/j.jpba.2015.02.046 .

Jovanović, Marko, Rakić, Tijana, Tumpa, Anja, Jančić-Stojanović, Biljana, "Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities" in Journal of Pharmaceutical and Biomedical Analysis, 110 (2015):42-48,
https://doi.org/10.1016/j.jpba.2015.02.046 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Ivanović, Darko
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2400
AB  - Hydrophilic interaction liquid chromatography (HILIC) has emerged as an alternative separation technique for small polar compounds. Design of Experiments (DoE) methodology in the analysis of the retention behavior and method development have been shown to be successful. This article addresses the retention behavior and optimization of chromatographic separation of a model mixture consisting of four sympathomimetic drugs (ephedrine, pseudoephedrine, phenylephrine, synephrine), on a bare silica column by HILIC. The acetonitrile content, pH of the aqueous phase, and concentration of ammonium acetate in aqueous phase were optimized according to the matrix of Box-Behnken design, and retention data were fitted to second-order polynomial models. The obtained coefficients of determination R-2 were higher than 0.990 and adjusted R-2 exceeded 0.972, while the lowest value for Predicted R-2 was 0.845. Beside of statistical analysis, graphical estimation of retention behavior was performed. In order to optimize the separation, indirect modeling of selectivity factors of critical peak pairs (the diastereoisomers ephedrine/pseudoephedrine and the positional isomers phenylephrine/synephrine) and grid point search approach were employed. After the development of the grids, optimal chromatographic conditions were selected (acetonitrile content 91%, pH of the aqueous phase 4.5 and ammonium acetate concetration 35mmolL(-1)), providing a total analysis time of 14min.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Instrumentation Science & Technology
T1  - Optimization of the Separation of Ephedrine, Pseudoephedrine, Phenylephrine, and Synephrine by Hydrophilic Interaction Liquid Chromatography Employing Experimental Design Methodology
VL  - 43
IS  - 2
SP  - 156
EP  - 169
DO  - 10.1080/10739149.2014.910670
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Ivanović, Darko and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "Hydrophilic interaction liquid chromatography (HILIC) has emerged as an alternative separation technique for small polar compounds. Design of Experiments (DoE) methodology in the analysis of the retention behavior and method development have been shown to be successful. This article addresses the retention behavior and optimization of chromatographic separation of a model mixture consisting of four sympathomimetic drugs (ephedrine, pseudoephedrine, phenylephrine, synephrine), on a bare silica column by HILIC. The acetonitrile content, pH of the aqueous phase, and concentration of ammonium acetate in aqueous phase were optimized according to the matrix of Box-Behnken design, and retention data were fitted to second-order polynomial models. The obtained coefficients of determination R-2 were higher than 0.990 and adjusted R-2 exceeded 0.972, while the lowest value for Predicted R-2 was 0.845. Beside of statistical analysis, graphical estimation of retention behavior was performed. In order to optimize the separation, indirect modeling of selectivity factors of critical peak pairs (the diastereoisomers ephedrine/pseudoephedrine and the positional isomers phenylephrine/synephrine) and grid point search approach were employed. After the development of the grids, optimal chromatographic conditions were selected (acetonitrile content 91%, pH of the aqueous phase 4.5 and ammonium acetate concetration 35mmolL(-1)), providing a total analysis time of 14min.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Instrumentation Science & Technology",
title = "Optimization of the Separation of Ephedrine, Pseudoephedrine, Phenylephrine, and Synephrine by Hydrophilic Interaction Liquid Chromatography Employing Experimental Design Methodology",
volume = "43",
number = "2",
pages = "156-169",
doi = "10.1080/10739149.2014.910670"
}

Jovanović, M., Rakić, T., Ivanović, D.,& Jančić-Stojanović, B.. (2015). Optimization of the Separation of Ephedrine, Pseudoephedrine, Phenylephrine, and Synephrine by Hydrophilic Interaction Liquid Chromatography Employing Experimental Design Methodology. in Instrumentation Science & Technology
Taylor & Francis Inc, Philadelphia., 43(2), 156-169.
https://doi.org/10.1080/10739149.2014.910670

Jovanović M, Rakić T, Ivanović D, Jančić-Stojanović B. Optimization of the Separation of Ephedrine, Pseudoephedrine, Phenylephrine, and Synephrine by Hydrophilic Interaction Liquid Chromatography Employing Experimental Design Methodology. in Instrumentation Science & Technology. 2015;43(2):156-169.
doi:10.1080/10739149.2014.910670 .

Jovanović, Marko, Rakić, Tijana, Ivanović, Darko, Jančić-Stojanović, Biljana, "Optimization of the Separation of Ephedrine, Pseudoephedrine, Phenylephrine, and Synephrine by Hydrophilic Interaction Liquid Chromatography Employing Experimental Design Methodology" in Instrumentation Science & Technology, 43, no. 2 (2015):156-169,
https://doi.org/10.1080/10739149.2014.910670 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Tumpa, Anja
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2398
AB  - This study presents the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol, its endo-isomer and three impurities following Quality by Design (QbD) approach. The main objective of the method was to identify the conditions where adequate separation quality in minimal analysis duration could be achieved within a robust region that guarantees the stability of method performance. The relationship between critical process parameters (acetonitrile content in the mobile phase, pH of the water phase and ammonium acetate concentration in the water phase) and critical quality attributes is created applying design of experiments methodology. The defined mathematical models and Monte Carlo simulation are used to evaluate the risk of uncertainty in models prediction and incertitude in adjusting the process parameters and to identify the design space. The borders of the design space are experimentally verified and confirmed that the quality of the method is preserved in this region. Moreover, Plackett-Burman design is applied for experimental robustness testing and method is fully validated to verify the adequacy of selected optimal conditions: the analytical column ZIC HILIC (100 mm x 4.6 mm, 5 mu m particle size); mobile phase consisted of acetonitrile-water phase (72 mM ammonium acetate, pH adjusted to 6.5 with glacial acetic acid) (86.7:13.3) v/v; column temperature 25 degrees C, mobile phase flow rate 1 mL min(-1), wavelength of detection 254 nm.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities
VL  - 110
SP  - 42
EP  - 48
DO  - 10.1016/j.jpba.2015.02.046
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Tumpa, Anja and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "This study presents the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol, its endo-isomer and three impurities following Quality by Design (QbD) approach. The main objective of the method was to identify the conditions where adequate separation quality in minimal analysis duration could be achieved within a robust region that guarantees the stability of method performance. The relationship between critical process parameters (acetonitrile content in the mobile phase, pH of the water phase and ammonium acetate concentration in the water phase) and critical quality attributes is created applying design of experiments methodology. The defined mathematical models and Monte Carlo simulation are used to evaluate the risk of uncertainty in models prediction and incertitude in adjusting the process parameters and to identify the design space. The borders of the design space are experimentally verified and confirmed that the quality of the method is preserved in this region. Moreover, Plackett-Burman design is applied for experimental robustness testing and method is fully validated to verify the adequacy of selected optimal conditions: the analytical column ZIC HILIC (100 mm x 4.6 mm, 5 mu m particle size); mobile phase consisted of acetonitrile-water phase (72 mM ammonium acetate, pH adjusted to 6.5 with glacial acetic acid) (86.7:13.3) v/v; column temperature 25 degrees C, mobile phase flow rate 1 mL min(-1), wavelength of detection 254 nm.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities",
volume = "110",
pages = "42-48",
doi = "10.1016/j.jpba.2015.02.046"
}

Jovanović, M., Rakić, T., Tumpa, A.,& Jančić-Stojanović, B.. (2015). Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 110, 42-48.
https://doi.org/10.1016/j.jpba.2015.02.046

Jovanović M, Rakić T, Tumpa A, Jančić-Stojanović B. Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities. in Journal of Pharmaceutical and Biomedical Analysis. 2015;110:42-48.
doi:10.1016/j.jpba.2015.02.046 .

Jovanović, Marko, Rakić, Tijana, Tumpa, Anja, Jančić-Stojanović, Biljana, "Quality by Design approach in the development of hydrophilic interaction liquid chromatographic method for the analysis of iohexol and its impurities" in Journal of Pharmaceutical and Biomedical Analysis, 110 (2015):42-48,
https://doi.org/10.1016/j.jpba.2015.02.046 . .

TY  - JOUR
AU  - Tumpa, Anja
AU  - Rakić, Tijana
AU  - Jovanović, Marko
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2332
AB  - The retention behavior of substances in hydrophilic interaction liquid chromatography (HILIC) is difficult to predict. Mixture investigated in this paper consists of acetylsalicylic acid, amlodipine, impurity A of amlodipine, and atenolol, a very often used combination in treatment of some cardiovascular diseases. Retention behavior dependence on the most influential chromatographic factors is described by mathematical models, with the special emphasis on pH of the mobile phase. D-optimal design is applied to generate more complex models and to obtain more accurate results. Comparison of Predicted R-2 values of quadratic and cubic model for pH dependence (0.847 and 0.934, respectively) shows that the cubic model has significantly better prediction ability than quadratic in the investigated system. After describing retention behavior, chemometrical tools (indirect modeling of complex chromatographic responses and grid point search optimization) are used to locate the optimal conditions for analyzed mixture in terms of satisfactory separation and minimal analysis duration. The optimal conditions are Column: Kinetex HILIC 100 A (100mmx4.5mm, 2.6 mu m particle size); injection volume: 5 mu L; flow rate: 1mLmin(-1); column temperature: 30 degrees C; detection wavelength: 254nm; mobile phase: acetonitrile-water phase (75mM ammonium acetate, pH 5.3) (91:9V/V).
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Liquid Chromatography & Related Technologies
T1  - Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology
VL  - 38
IS  - 16
SP  - 1555
EP  - 1560
DO  - 10.1080/10826076.2015.1077863
ER  - 

@article{
author = "Tumpa, Anja and Rakić, Tijana and Jovanović, Marko and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "The retention behavior of substances in hydrophilic interaction liquid chromatography (HILIC) is difficult to predict. Mixture investigated in this paper consists of acetylsalicylic acid, amlodipine, impurity A of amlodipine, and atenolol, a very often used combination in treatment of some cardiovascular diseases. Retention behavior dependence on the most influential chromatographic factors is described by mathematical models, with the special emphasis on pH of the mobile phase. D-optimal design is applied to generate more complex models and to obtain more accurate results. Comparison of Predicted R-2 values of quadratic and cubic model for pH dependence (0.847 and 0.934, respectively) shows that the cubic model has significantly better prediction ability than quadratic in the investigated system. After describing retention behavior, chemometrical tools (indirect modeling of complex chromatographic responses and grid point search optimization) are used to locate the optimal conditions for analyzed mixture in terms of satisfactory separation and minimal analysis duration. The optimal conditions are Column: Kinetex HILIC 100 A (100mmx4.5mm, 2.6 mu m particle size); injection volume: 5 mu L; flow rate: 1mLmin(-1); column temperature: 30 degrees C; detection wavelength: 254nm; mobile phase: acetonitrile-water phase (75mM ammonium acetate, pH 5.3) (91:9V/V).",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Liquid Chromatography & Related Technologies",
title = "Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology",
volume = "38",
number = "16",
pages = "1555-1560",
doi = "10.1080/10826076.2015.1077863"
}

Tumpa, A., Rakić, T., Jovanović, M.,& Jančić-Stojanović, B.. (2015). Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology. in Journal of Liquid Chromatography & Related Technologies
Taylor & Francis Inc, Philadelphia., 38(16), 1555-1560.
https://doi.org/10.1080/10826076.2015.1077863

Tumpa A, Rakić T, Jovanović M, Jančić-Stojanović B. Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology. in Journal of Liquid Chromatography & Related Technologies. 2015;38(16):1555-1560.
doi:10.1080/10826076.2015.1077863 .

Tumpa, Anja, Rakić, Tijana, Jovanović, Marko, Jančić-Stojanović, Biljana, "Optimization of Chromatographic Separation of Acetylsalicylic Acid, Amlodipine, Impurity a of Amlodipine, and Atenolol in Hydrophilic Interaction Liquid Chromatography Employing DoE Methodology" in Journal of Liquid Chromatography & Related Technologies, 38, no. 16 (2015):1555-1560,
https://doi.org/10.1080/10826076.2015.1077863 . .

TY  - JOUR
AU  - Maksić, Jelena
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Popović, Igor
AU  - Ivanović, Darko
AU  - Jančić-Stojanović, Biljana
PY  - 2015
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2318
AB  - In this paper, chromatographic analysis of active substance olopatadine hydrochloride, which is used in eye drops as antihistaminic agent, and its impurity E isomer by hydrophilic interaction liquid chromatography (HILIC) and application of design of experiments (DoE) methodology are presented. In addition, benzalkonium chloride is very often used as a preservative in eye drops. Therefore, the evaluation of its chromatographic behavior in HILIC was carried out as well. In order to estimate chromatographic behavior and set optimal chromatographic conditions, DoE methodology was applied. After the selection of important chromatographic factors, Box-Behnken design was utilized, and on the basis of the obtained models factor effects were examined. Then, multi-objective robust optimization is performed aiming to obtain chromatographic conditions that comply with several quality criteria simultaneously: adequate and robust separation of critical peak pair and maximum retention of the first eluting peak. The optimal conditions are identified by using grid point search methodology. The experimental verification confirmed the adequacy of the defined optimal conditions. Finally, under optimal chromatographic conditions, the method was validated and applicability of the proposed method was confirmed.
PB  - Oxford Univ Press Inc, Cary
T2  - Journal of Chromatographic Science
T1  - Chromatographic Analysis of Olopatadine in Hydrophilic Interaction Liquid Chromatography
VL  - 53
IS  - 5
SP  - 680
EP  - 686
DO  - 10.1093/chromsci/bmu102
ER  - 

@article{
author = "Maksić, Jelena and Jovanović, Marko and Rakić, Tijana and Popović, Igor and Ivanović, Darko and Jančić-Stojanović, Biljana",
year = "2015",
abstract = "In this paper, chromatographic analysis of active substance olopatadine hydrochloride, which is used in eye drops as antihistaminic agent, and its impurity E isomer by hydrophilic interaction liquid chromatography (HILIC) and application of design of experiments (DoE) methodology are presented. In addition, benzalkonium chloride is very often used as a preservative in eye drops. Therefore, the evaluation of its chromatographic behavior in HILIC was carried out as well. In order to estimate chromatographic behavior and set optimal chromatographic conditions, DoE methodology was applied. After the selection of important chromatographic factors, Box-Behnken design was utilized, and on the basis of the obtained models factor effects were examined. Then, multi-objective robust optimization is performed aiming to obtain chromatographic conditions that comply with several quality criteria simultaneously: adequate and robust separation of critical peak pair and maximum retention of the first eluting peak. The optimal conditions are identified by using grid point search methodology. The experimental verification confirmed the adequacy of the defined optimal conditions. Finally, under optimal chromatographic conditions, the method was validated and applicability of the proposed method was confirmed.",
publisher = "Oxford Univ Press Inc, Cary",
journal = "Journal of Chromatographic Science",
title = "Chromatographic Analysis of Olopatadine in Hydrophilic Interaction Liquid Chromatography",
volume = "53",
number = "5",
pages = "680-686",
doi = "10.1093/chromsci/bmu102"
}

Maksić, J., Jovanović, M., Rakić, T., Popović, I., Ivanović, D.,& Jančić-Stojanović, B.. (2015). Chromatographic Analysis of Olopatadine in Hydrophilic Interaction Liquid Chromatography. in Journal of Chromatographic Science
Oxford Univ Press Inc, Cary., 53(5), 680-686.
https://doi.org/10.1093/chromsci/bmu102

Maksić J, Jovanović M, Rakić T, Popović I, Ivanović D, Jančić-Stojanović B. Chromatographic Analysis of Olopatadine in Hydrophilic Interaction Liquid Chromatography. in Journal of Chromatographic Science. 2015;53(5):680-686.
doi:10.1093/chromsci/bmu102 .

Maksić, Jelena, Jovanović, Marko, Rakić, Tijana, Popović, Igor, Ivanović, Darko, Jančić-Stojanović, Biljana, "Chromatographic Analysis of Olopatadine in Hydrophilic Interaction Liquid Chromatography" in Journal of Chromatographic Science, 53, no. 5 (2015):680-686,
https://doi.org/10.1093/chromsci/bmu102 . .

TY  - JOUR
AU  - Rakić, Tijana
AU  - Jovanović, Marko
AU  - Tumpa, Anja
AU  - Jančić-Stojanović, Biljana
AU  - Medenica, Mirjana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2277
AB  - This paper presents the robust optimization of hydrophilic interaction liquid chromatographic method for the analysis of bisoprolol and its impurities A and C. Chemometric strategy is applied for detailed understanding of system's behavior and establishing the mathematical relationship between investigated factors (acetonitrile content in the mobile phase, pH of the water phase and buffer concentration in the water phase) and chromatographic responses. Grid point search methodology is then performed with the aim to identify the point with satisfactory separation quality for all analyzed substances and to achieve minimal analysis duration. Oversized chromatograms are made creating an extra band broadening for each chromatographic peak corresponding to the value of standard deviation in order to evaluate the incertitude originating from the model uncertainty. On the other hand, the uncertainty originating from the variation of experimental parameters is assessed by simulated experimental design robustness testing. Finally, the obtained robust optimal conditions were: chromatographic column Kinetex HILIC 100Å (100 mm x 4.5 mm, 2.6 mm particle size); mobile phase composed of acetonitrile - water phase (35 mM ammonium acetate, pH 4.9 adjusted with glacial acetic acid) (85:15 v/v); flow rate 1 mL min-1, column temperature 30°C and UV detection at 254 nm.
AB  - U ovom radu prikazana je optimizacija metode tečne hromatografije hidrofilnih interakcija za analizu bisoprolola i njegovih nečistoća A i C uz procenu mogućnosti variranja položaja pikova. Primenjena je hemometrijska strategija za detaljno razumevanje ponašanja sistema i uspostavljanje matematičke veze između ispitivanih faktora (sadržaj acetonitrila u mobilnoj fazi, pH vrednost vodene faze i koncentracija pufera u vodenoj fazi) i hromatografskih odgovora. Enumerativna tehnika optimizacije upotrebljena je za identifikaciju tačke koja pokazuje zadovoljavajući kvalitet razdvajanja svih ispitivanih supstanci i minimalno vreme trajanja analize. Kreirani su prošireni hromatogrami širenjem pikova svih ispitivanih supstanci za vrednosti standardne devijacije kako bi se procenila mogućnost greške odgovora koja potiče iz greške matematičkog modela. Mogućnost greške koja potiče iz greške u podešavanju eksperimentalnih parametara procenjena je simuliranim testiranjem robusnosti primenom eksperimentalnog dizajna. Konačno, dobijeni optimalni uslovi bili su: hromatografska kolona Kinetex HILIC 100Å (100 mm x 4,5 mm, 2,6 mm veličina čestica); mobilna faza sastavljena od smeše acetonitril - vodena faza (35 mM amonijum-acetat, pH 4,9 podešen glacijalnom sirćetnom kiselinom) (85:15 v/v); protok 1 mL min-1, temperatura kolone 30°C i UV detekcija na 254 nm.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Optimization of HILIC method for the analysis of bisoprolol and its impurities considering uncertainties in peak position
T1  - Optimizacija HILIC metode za analizu bisoprolola i njegovih nečistoća uz procenu mogućnosti variranja položaja pikova
VL  - 64
IS  - 2
SP  - 95
EP  - 111
DO  - 10.5937/arhfarm1402095R
ER  - 

@article{
author = "Rakić, Tijana and Jovanović, Marko and Tumpa, Anja and Jančić-Stojanović, Biljana and Medenica, Mirjana",
year = "2014",
abstract = "This paper presents the robust optimization of hydrophilic interaction liquid chromatographic method for the analysis of bisoprolol and its impurities A and C. Chemometric strategy is applied for detailed understanding of system's behavior and establishing the mathematical relationship between investigated factors (acetonitrile content in the mobile phase, pH of the water phase and buffer concentration in the water phase) and chromatographic responses. Grid point search methodology is then performed with the aim to identify the point with satisfactory separation quality for all analyzed substances and to achieve minimal analysis duration. Oversized chromatograms are made creating an extra band broadening for each chromatographic peak corresponding to the value of standard deviation in order to evaluate the incertitude originating from the model uncertainty. On the other hand, the uncertainty originating from the variation of experimental parameters is assessed by simulated experimental design robustness testing. Finally, the obtained robust optimal conditions were: chromatographic column Kinetex HILIC 100Å (100 mm x 4.5 mm, 2.6 mm particle size); mobile phase composed of acetonitrile - water phase (35 mM ammonium acetate, pH 4.9 adjusted with glacial acetic acid) (85:15 v/v); flow rate 1 mL min-1, column temperature 30°C and UV detection at 254 nm., U ovom radu prikazana je optimizacija metode tečne hromatografije hidrofilnih interakcija za analizu bisoprolola i njegovih nečistoća A i C uz procenu mogućnosti variranja položaja pikova. Primenjena je hemometrijska strategija za detaljno razumevanje ponašanja sistema i uspostavljanje matematičke veze između ispitivanih faktora (sadržaj acetonitrila u mobilnoj fazi, pH vrednost vodene faze i koncentracija pufera u vodenoj fazi) i hromatografskih odgovora. Enumerativna tehnika optimizacije upotrebljena je za identifikaciju tačke koja pokazuje zadovoljavajući kvalitet razdvajanja svih ispitivanih supstanci i minimalno vreme trajanja analize. Kreirani su prošireni hromatogrami širenjem pikova svih ispitivanih supstanci za vrednosti standardne devijacije kako bi se procenila mogućnost greške odgovora koja potiče iz greške matematičkog modela. Mogućnost greške koja potiče iz greške u podešavanju eksperimentalnih parametara procenjena je simuliranim testiranjem robusnosti primenom eksperimentalnog dizajna. Konačno, dobijeni optimalni uslovi bili su: hromatografska kolona Kinetex HILIC 100Å (100 mm x 4,5 mm, 2,6 mm veličina čestica); mobilna faza sastavljena od smeše acetonitril - vodena faza (35 mM amonijum-acetat, pH 4,9 podešen glacijalnom sirćetnom kiselinom) (85:15 v/v); protok 1 mL min-1, temperatura kolone 30°C i UV detekcija na 254 nm.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Optimization of HILIC method for the analysis of bisoprolol and its impurities considering uncertainties in peak position, Optimizacija HILIC metode za analizu bisoprolola i njegovih nečistoća uz procenu mogućnosti variranja položaja pikova",
volume = "64",
number = "2",
pages = "95-111",
doi = "10.5937/arhfarm1402095R"
}

Rakić, T., Jovanović, M., Tumpa, A., Jančić-Stojanović, B.,& Medenica, M.. (2014). Optimization of HILIC method for the analysis of bisoprolol and its impurities considering uncertainties in peak position. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 64(2), 95-111.
https://doi.org/10.5937/arhfarm1402095R

Rakić T, Jovanović M, Tumpa A, Jančić-Stojanović B, Medenica M. Optimization of HILIC method for the analysis of bisoprolol and its impurities considering uncertainties in peak position. in Arhiv za farmaciju. 2014;64(2):95-111.
doi:10.5937/arhfarm1402095R .

Rakić, Tijana, Jovanović, Marko, Tumpa, Anja, Jančić-Stojanović, Biljana, Medenica, Mirjana, "Optimization of HILIC method for the analysis of bisoprolol and its impurities considering uncertainties in peak position" in Arhiv za farmaciju, 64, no. 2 (2014):95-111,
https://doi.org/10.5937/arhfarm1402095R . .

TY  - JOUR
AU  - Rakić, Tijana
AU  - Kasagić-Vujanović, Irena
AU  - Jovanović, Marko
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2223
AB  - This paper presents the development and optimization of a liquid chromatographic method for the determination of fluconazole and its impurities by experimental design methodology. Four experimental design types were applied: two-level full factorial design, central composite design, Box-Behnken design, and three-level full factorial design. The advantages and drawbacks of each design are described and detailed statistical evaluation of mathematical models was performed. The central composite design and three-level full factorial design created significantly better models comparing to the other methods. As the central composite design requires a smaller number of experiments, its models were used for theoretical examination of experimental space. Multiobjective optimization aiming to achieve maximal separation of all investigated substances and minimal analysis duration was performed by a grid point search. The defined optimal separation was achieved on a C-18 (125mmx4mm, 5 mu m particle size) column with a mobile phase consisting of acetonitrile and water (5mM ammonium formate) (15:85, v/v); a column temperature of 25 degrees C; a flow rate of 1.2mLmin(-1); and a detection wavelength of 260nm.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Analytical Letters
T1  - Comparison of Full Factorial Design, Central Composite Design, and Box-Behnken Design in Chromatographic Method Development for the Determination of Fluconazole and Its Impurities
VL  - 47
IS  - 8
SP  - 1334
EP  - 1347
DO  - 10.1080/00032719.2013.867503
ER  - 

@article{
author = "Rakić, Tijana and Kasagić-Vujanović, Irena and Jovanović, Marko and Jančić-Stojanović, Biljana and Ivanović, Darko",
year = "2014",
abstract = "This paper presents the development and optimization of a liquid chromatographic method for the determination of fluconazole and its impurities by experimental design methodology. Four experimental design types were applied: two-level full factorial design, central composite design, Box-Behnken design, and three-level full factorial design. The advantages and drawbacks of each design are described and detailed statistical evaluation of mathematical models was performed. The central composite design and three-level full factorial design created significantly better models comparing to the other methods. As the central composite design requires a smaller number of experiments, its models were used for theoretical examination of experimental space. Multiobjective optimization aiming to achieve maximal separation of all investigated substances and minimal analysis duration was performed by a grid point search. The defined optimal separation was achieved on a C-18 (125mmx4mm, 5 mu m particle size) column with a mobile phase consisting of acetonitrile and water (5mM ammonium formate) (15:85, v/v); a column temperature of 25 degrees C; a flow rate of 1.2mLmin(-1); and a detection wavelength of 260nm.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Analytical Letters",
title = "Comparison of Full Factorial Design, Central Composite Design, and Box-Behnken Design in Chromatographic Method Development for the Determination of Fluconazole and Its Impurities",
volume = "47",
number = "8",
pages = "1334-1347",
doi = "10.1080/00032719.2013.867503"
}

Rakić, T., Kasagić-Vujanović, I., Jovanović, M., Jančić-Stojanović, B.,& Ivanović, D.. (2014). Comparison of Full Factorial Design, Central Composite Design, and Box-Behnken Design in Chromatographic Method Development for the Determination of Fluconazole and Its Impurities. in Analytical Letters
Taylor & Francis Inc, Philadelphia., 47(8), 1334-1347.
https://doi.org/10.1080/00032719.2013.867503

Rakić T, Kasagić-Vujanović I, Jovanović M, Jančić-Stojanović B, Ivanović D. Comparison of Full Factorial Design, Central Composite Design, and Box-Behnken Design in Chromatographic Method Development for the Determination of Fluconazole and Its Impurities. in Analytical Letters. 2014;47(8):1334-1347.
doi:10.1080/00032719.2013.867503 .

Rakić, Tijana, Kasagić-Vujanović, Irena, Jovanović, Marko, Jančić-Stojanović, Biljana, Ivanović, Darko, "Comparison of Full Factorial Design, Central Composite Design, and Box-Behnken Design in Chromatographic Method Development for the Determination of Fluconazole and Its Impurities" in Analytical Letters, 47, no. 8 (2014):1334-1347,
https://doi.org/10.1080/00032719.2013.867503 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2191
AB  - Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.
PB  - Springer Heidelberg, Heidelberg
T2  - Analytical and Bioanalytical Chemistry
T1  - Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography
VL  - 406
IS  - 17
SP  - 4217
EP  - 4232
DO  - 10.1007/s00216-014-7808-6
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana and Ivanović, Darko and Medenica, Mirjana",
year = "2014",
abstract = "Hydrophilic interaction liquid chromatography (HILIC) has emerged in recent years as a valuable alternative to reversed-phase liquid chromatography in the analysis of polar compounds. Research in HILIC is divided into two directions: the assessment of the retention mechanism and retention behavior, and the development of HILIC methods. In this work, four polar neutral analytes (iohexol and its related compounds A, B, and C) were analyzed on two silica and two diol columns in HILIC mode with the aim to investigate thoroughly the retention mechanisms and retention behavior of polar neutral compounds on these four columns. The adsorption and partition contribution to the overall HILIC retention mechanism was investigated by fitting the retention data to linear (adsorption and partition) and nonlinear (mixed-retention and quadratic) theoretical models. On the other hand, the establishment of empirical second-order polynomial retention models on the basis of D-optimal design made possible the estimation of the simultaneous influence of several mobile-phase-related factors. Furthermore, these models were also used as the basis for the application of indirect modeling of the selectivity factor and a grid point search approach in order to achieve the optimal separation of analytes. After the optimization goals had been set, the grids were searched and the optimal conditions were identified. Finally, the optimized method was subjected to validation.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Analytical and Bioanalytical Chemistry",
title = "Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography",
volume = "406",
number = "17",
pages = "4217-4232",
doi = "10.1007/s00216-014-7808-6"
}

Jovanović, M., Rakić, T., Jančić-Stojanović, B., Ivanović, D.,& Medenica, M.. (2014). Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography. in Analytical and Bioanalytical Chemistry
Springer Heidelberg, Heidelberg., 406(17), 4217-4232.
https://doi.org/10.1007/s00216-014-7808-6

Jovanović M, Rakić T, Jančić-Stojanović B, Ivanović D, Medenica M. Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography. in Analytical and Bioanalytical Chemistry. 2014;406(17):4217-4232.
doi:10.1007/s00216-014-7808-6 .

Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, Ivanović, Darko, Medenica, Mirjana, "Retention mechanism assessment and method development for the analysis of iohexol and its related compounds in hydrophilic interaction liquid chromatography" in Analytical and Bioanalytical Chemistry, 406, no. 17 (2014):4217-4232,
https://doi.org/10.1007/s00216-014-7808-6 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
PY  - 2014
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2151
AB  - Hydrophilic interaction liquid chromatography (HILIC) has found application in the determination of polar molecules. This alternative type of chromatography has become increasingly popular in the last five years and a considerable number of articles regarding the elucidation of its retention mechanisms and the development of methods are available. In order to achieve these goals, various types of theoretical and empirical mathematical models were utilized. However, the knowledge obtained from these models was the subject of various interpretations. The goal of this article is to list and discuss the papers in which these models were used in HILIC and give proper theoretical background of the models. In general, theoretical models in HILIC were applied in order to acquire the knowledge of dominant processes in the retention mechanism, retention prediction, and quantitative description of the influence of mobile phase-related factors on the retention and selectivity of the analytes on different types of stationary phases. In addition, empirical models were used for detailed assessment of the retention behavior in terms of both single factor and factor interactions influence on analyte retention and selectivity. Furthermore, they have also shown a great potential in the optimization of HILIC methods in the method development process.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Instrumentation Science & Technology
T1  - Theoretical and empirical models in hydrophilic interaction liquid chromatography
VL  - 42
IS  - 3
SP  - 230
EP  - 266
DO  - 10.1080/10739149.2013.865214
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana",
year = "2014",
abstract = "Hydrophilic interaction liquid chromatography (HILIC) has found application in the determination of polar molecules. This alternative type of chromatography has become increasingly popular in the last five years and a considerable number of articles regarding the elucidation of its retention mechanisms and the development of methods are available. In order to achieve these goals, various types of theoretical and empirical mathematical models were utilized. However, the knowledge obtained from these models was the subject of various interpretations. The goal of this article is to list and discuss the papers in which these models were used in HILIC and give proper theoretical background of the models. In general, theoretical models in HILIC were applied in order to acquire the knowledge of dominant processes in the retention mechanism, retention prediction, and quantitative description of the influence of mobile phase-related factors on the retention and selectivity of the analytes on different types of stationary phases. In addition, empirical models were used for detailed assessment of the retention behavior in terms of both single factor and factor interactions influence on analyte retention and selectivity. Furthermore, they have also shown a great potential in the optimization of HILIC methods in the method development process.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Instrumentation Science & Technology",
title = "Theoretical and empirical models in hydrophilic interaction liquid chromatography",
volume = "42",
number = "3",
pages = "230-266",
doi = "10.1080/10739149.2013.865214"
}

Jovanović, M., Rakić, T.,& Jančić-Stojanović, B.. (2014). Theoretical and empirical models in hydrophilic interaction liquid chromatography. in Instrumentation Science & Technology
Taylor & Francis Inc, Philadelphia., 42(3), 230-266.
https://doi.org/10.1080/10739149.2013.865214

Jovanović M, Rakić T, Jančić-Stojanović B. Theoretical and empirical models in hydrophilic interaction liquid chromatography. in Instrumentation Science & Technology. 2014;42(3):230-266.
doi:10.1080/10739149.2013.865214 .

Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, "Theoretical and empirical models in hydrophilic interaction liquid chromatography" in Instrumentation Science & Technology, 42, no. 3 (2014):230-266,
https://doi.org/10.1080/10739149.2013.865214 . .

TY  - JOUR
AU  - Rakić, Tijana
AU  - Jovanović, Marko
AU  - Dumić, Aleksandra
AU  - Pekić, Marina
AU  - Ribić, Sanja
AU  - Jančić-Stojanović, Biljana
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1982
AB  - This paper presents multiobjective optimization of complex mixtures separation in hydrophilic interaction liquid chromatography (HILIC). The selected model mixture consisted of five psychotropic drugs: clozapine, thioridazine, sulpiride, pheniramine and lamotrigine. Three factors related to the mobile phase composition (acetonitrile content, pH of the water phase and concentration of ammonium acetate) were optimized in order to achieve the following goals: maximal separation quality, minimal total analysis duration and robustness of an optimum. The consideration of robustness in early phases of the method development provides reliable methods with low risk for failure in validation phase. The simultaneous optimization of all goals was achieved by multiple threshold approach combined with grid point search. The identified optimal separation conditions (acetonitrile content 83%, pH of the water phase 3.5 and ammonium acetate content in water phase 14 mM) were experimentally verified.
PB  - Slovensko Kemijsko Drustvo, Ljubljana
T2  - Acta Chimica Slovenica
T1  - Robust Optimization of Psychotropic Drug Mixture Separation in Hydrophilic Interaction Liquid Chromatography
VL  - 60
IS  - 2
SP  - 411
EP  - 415
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1982
ER  - 

@article{
author = "Rakić, Tijana and Jovanović, Marko and Dumić, Aleksandra and Pekić, Marina and Ribić, Sanja and Jančić-Stojanović, Biljana",
year = "2013",
abstract = "This paper presents multiobjective optimization of complex mixtures separation in hydrophilic interaction liquid chromatography (HILIC). The selected model mixture consisted of five psychotropic drugs: clozapine, thioridazine, sulpiride, pheniramine and lamotrigine. Three factors related to the mobile phase composition (acetonitrile content, pH of the water phase and concentration of ammonium acetate) were optimized in order to achieve the following goals: maximal separation quality, minimal total analysis duration and robustness of an optimum. The consideration of robustness in early phases of the method development provides reliable methods with low risk for failure in validation phase. The simultaneous optimization of all goals was achieved by multiple threshold approach combined with grid point search. The identified optimal separation conditions (acetonitrile content 83%, pH of the water phase 3.5 and ammonium acetate content in water phase 14 mM) were experimentally verified.",
publisher = "Slovensko Kemijsko Drustvo, Ljubljana",
journal = "Acta Chimica Slovenica",
title = "Robust Optimization of Psychotropic Drug Mixture Separation in Hydrophilic Interaction Liquid Chromatography",
volume = "60",
number = "2",
pages = "411-415",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1982"
}

Rakić, T., Jovanović, M., Dumić, A., Pekić, M., Ribić, S.,& Jančić-Stojanović, B.. (2013). Robust Optimization of Psychotropic Drug Mixture Separation in Hydrophilic Interaction Liquid Chromatography. in Acta Chimica Slovenica
Slovensko Kemijsko Drustvo, Ljubljana., 60(2), 411-415.
https://hdl.handle.net/21.15107/rcub_farfar_1982

Rakić T, Jovanović M, Dumić A, Pekić M, Ribić S, Jančić-Stojanović B. Robust Optimization of Psychotropic Drug Mixture Separation in Hydrophilic Interaction Liquid Chromatography. in Acta Chimica Slovenica. 2013;60(2):411-415.
https://hdl.handle.net/21.15107/rcub_farfar_1982 .

Rakić, Tijana, Jovanović, Marko, Dumić, Aleksandra, Pekić, Marina, Ribić, Sanja, Jančić-Stojanović, Biljana, "Robust Optimization of Psychotropic Drug Mixture Separation in Hydrophilic Interaction Liquid Chromatography" in Acta Chimica Slovenica, 60, no. 2 (2013):411-415,
https://hdl.handle.net/21.15107/rcub_farfar_1982 .

TY  - JOUR
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Jovanović, Marko
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3419
AB  - This paper investigates the ability of seven chromatographic response functions to measure the quality of chromatograms obtained in hydrophilic interaction liquid chromatography (HILIC). First, the functions were tested on a set of simulated chromatograms and differences in their mathematical design were discussed. Second, the functions were evaluated on the experimentally obtained chromatograms in HILIC analysis of model mixture consisted of beta agonists and antagonists. The ranking of chromatograms obtained by different functions was significantly different, implying that the accuracy of the optimization procedure is strongly dependent on the function that was selected as an output. Investigation of potential drawbacks of each function was conducted and general recommendations concerning the use of chromatographic response functions in optimization strategies are proposed.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Analytical Letters
T1  - Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System
VL  - 46
IS  - 8
SP  - 1198
EP  - 1212
DO  - 10.1080/00032719.2012.755689
ER  - 

@article{
author = "Rakić, Tijana and Jančić-Stojanović, Biljana and Jovanović, Marko and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2013",
abstract = "This paper investigates the ability of seven chromatographic response functions to measure the quality of chromatograms obtained in hydrophilic interaction liquid chromatography (HILIC). First, the functions were tested on a set of simulated chromatograms and differences in their mathematical design were discussed. Second, the functions were evaluated on the experimentally obtained chromatograms in HILIC analysis of model mixture consisted of beta agonists and antagonists. The ranking of chromatograms obtained by different functions was significantly different, implying that the accuracy of the optimization procedure is strongly dependent on the function that was selected as an output. Investigation of potential drawbacks of each function was conducted and general recommendations concerning the use of chromatographic response functions in optimization strategies are proposed.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Analytical Letters",
title = "Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System",
volume = "46",
number = "8",
pages = "1198-1212",
doi = "10.1080/00032719.2012.755689"
}

Rakić, T., Jančić-Stojanović, B., Jovanović, M., Malenović, A., Ivanović, D.,& Medenica, M.. (2013). Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System. in Analytical Letters
Taylor & Francis Inc, Philadelphia., 46(8), 1198-1212.
https://doi.org/10.1080/00032719.2012.755689

Rakić T, Jančić-Stojanović B, Jovanović M, Malenović A, Ivanović D, Medenica M. Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System. in Analytical Letters. 2013;46(8):1198-1212.
doi:10.1080/00032719.2012.755689 .

Rakić, Tijana, Jančić-Stojanović, Biljana, Jovanović, Marko, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System" in Analytical Letters, 46, no. 8 (2013):1198-1212,
https://doi.org/10.1080/00032719.2012.755689 . .

TY  - JOUR
AU  - Kasagić-Vujanović, Irena
AU  - Malenović, Anđelija
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1920
AB  - This paper presents the chemometrically assisted optimization and validation of the RP-HPLC method intended for the quantitative analysis of itraconazole and its impurities in pharmaceutical dosage forms. To reach the desired chromatographic resolution with a limited number of experiments in a minimum amount of time, Box-Behnken design was used to simultaneously optimize some important chromatographic parameters, such as the acetonitrile content in the mobile phase, pH of the aqueous phase and the column temperature. Separation between itraconazole and impurity F was identified as critical and selected as a response during the optimization. The set optimal mobile phase composition was acetonitrile/water pH 2.5 adjusted with o-phosphoric acid (50:50, V/V). Separations were performed on a Zorbax Eclipse XDB-C18, 4.6 x 150 mm, 5 mu m particle size column with the flow rate 1 mL min(-1), column temperature set at 30 degrees C and UV detection at 256 nm. The established method was then subjected to method validation and the required validation parameters were tested. For the robustness evaluation, fractional factorial 2(4-1) design was utilized and factors that might significantly affect the system performance were defined. As other validation parameters were also found to be suitable, the possibility to apply the proposed method for the determination of itraconazole, its impurities B and F in any laboratory under different circumstances has been proven.
PB  - Hrvatsko Farmaceutsko Drustov (HFD)-Croation Pharmaceutical Soc, Zagreb
T2  - Acta Pharmaceutica
T1  - Chemometrically assissted optimization and validation of RP-HPLC method for the analysis of itraconazole and its impurities
VL  - 63
IS  - 2
SP  - 159
EP  - 173
DO  - 10.2478/acph-2013-0015
ER  - 

@article{
author = "Kasagić-Vujanović, Irena and Malenović, Anđelija and Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana and Ivanović, Darko",
year = "2013",
abstract = "This paper presents the chemometrically assisted optimization and validation of the RP-HPLC method intended for the quantitative analysis of itraconazole and its impurities in pharmaceutical dosage forms. To reach the desired chromatographic resolution with a limited number of experiments in a minimum amount of time, Box-Behnken design was used to simultaneously optimize some important chromatographic parameters, such as the acetonitrile content in the mobile phase, pH of the aqueous phase and the column temperature. Separation between itraconazole and impurity F was identified as critical and selected as a response during the optimization. The set optimal mobile phase composition was acetonitrile/water pH 2.5 adjusted with o-phosphoric acid (50:50, V/V). Separations were performed on a Zorbax Eclipse XDB-C18, 4.6 x 150 mm, 5 mu m particle size column with the flow rate 1 mL min(-1), column temperature set at 30 degrees C and UV detection at 256 nm. The established method was then subjected to method validation and the required validation parameters were tested. For the robustness evaluation, fractional factorial 2(4-1) design was utilized and factors that might significantly affect the system performance were defined. As other validation parameters were also found to be suitable, the possibility to apply the proposed method for the determination of itraconazole, its impurities B and F in any laboratory under different circumstances has been proven.",
publisher = "Hrvatsko Farmaceutsko Drustov (HFD)-Croation Pharmaceutical Soc, Zagreb",
journal = "Acta Pharmaceutica",
title = "Chemometrically assissted optimization and validation of RP-HPLC method for the analysis of itraconazole and its impurities",
volume = "63",
number = "2",
pages = "159-173",
doi = "10.2478/acph-2013-0015"
}

Kasagić-Vujanović, I., Malenović, A., Jovanović, M., Rakić, T., Jančić-Stojanović, B.,& Ivanović, D.. (2013). Chemometrically assissted optimization and validation of RP-HPLC method for the analysis of itraconazole and its impurities. in Acta Pharmaceutica
Hrvatsko Farmaceutsko Drustov (HFD)-Croation Pharmaceutical Soc, Zagreb., 63(2), 159-173.
https://doi.org/10.2478/acph-2013-0015

Kasagić-Vujanović I, Malenović A, Jovanović M, Rakić T, Jančić-Stojanović B, Ivanović D. Chemometrically assissted optimization and validation of RP-HPLC method for the analysis of itraconazole and its impurities. in Acta Pharmaceutica. 2013;63(2):159-173.
doi:10.2478/acph-2013-0015 .

Kasagić-Vujanović, Irena, Malenović, Anđelija, Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, Ivanović, Darko, "Chemometrically assissted optimization and validation of RP-HPLC method for the analysis of itraconazole and its impurities" in Acta Pharmaceutica, 63, no. 2 (2013):159-173,
https://doi.org/10.2478/acph-2013-0015 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Jančić-Stojanović, Biljana
AU  - Rakić, Tijana
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2001
AB  - Five different columns (two silica, two cyanopropyl and one diol) were investigated in hydrophilic interaction liquid chromatography (HILIC). For the assessment of columns behavior in HILIC mode, six basic drugs (lamotrigine, thioridazine, clozapine, chlorpheniramine, pheniramine and sulpiride) were chosen. The assessment of the influence of the concentration of organic modifier on analytes' retention on each column was provided by fitting the retention data into theoretical models. Utilizing the statistical analysis, the selection of the model that provides better prediction of the retention behavior was enabled. Dual RP-HILIC mechanism was suggested on cyanopropyl and diol columns, therefore the transition points between the two mechanisms on these columns were calculated. Furthermore, in order to investigate the impact of three factors simultaneously on the retention behavior of the analyzed substances on Betasil Silica column, chemometrically-aided empirical models were built. The experiments were conducted according to the matrix of Box-Behnken design and on the basis of the retention data, six quadratic models were obtained and their adequacy was confirmed using ANOVA test. The obtained coefficients of quadratic models enabled the elucidation of both single factor and factor interactions influence. This was also graphically presented in 3D response surface plots.
PB  - Versita, Warsaw
T2  - Central European Journal of Chemistry
T1  - Five different columns in the analysis of basic drugs in hydrophilic interaction liquid chromatography
VL  - 11
IS  - 7
SP  - 1150
EP  - 1162
DO  - 10.2478/s11532-013-0245-0
ER  - 

@article{
author = "Jovanović, Marko and Jančić-Stojanović, Biljana and Rakić, Tijana and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2013",
abstract = "Five different columns (two silica, two cyanopropyl and one diol) were investigated in hydrophilic interaction liquid chromatography (HILIC). For the assessment of columns behavior in HILIC mode, six basic drugs (lamotrigine, thioridazine, clozapine, chlorpheniramine, pheniramine and sulpiride) were chosen. The assessment of the influence of the concentration of organic modifier on analytes' retention on each column was provided by fitting the retention data into theoretical models. Utilizing the statistical analysis, the selection of the model that provides better prediction of the retention behavior was enabled. Dual RP-HILIC mechanism was suggested on cyanopropyl and diol columns, therefore the transition points between the two mechanisms on these columns were calculated. Furthermore, in order to investigate the impact of three factors simultaneously on the retention behavior of the analyzed substances on Betasil Silica column, chemometrically-aided empirical models were built. The experiments were conducted according to the matrix of Box-Behnken design and on the basis of the retention data, six quadratic models were obtained and their adequacy was confirmed using ANOVA test. The obtained coefficients of quadratic models enabled the elucidation of both single factor and factor interactions influence. This was also graphically presented in 3D response surface plots.",
publisher = "Versita, Warsaw",
journal = "Central European Journal of Chemistry",
title = "Five different columns in the analysis of basic drugs in hydrophilic interaction liquid chromatography",
volume = "11",
number = "7",
pages = "1150-1162",
doi = "10.2478/s11532-013-0245-0"
}

Jovanović, M., Jančić-Stojanović, B., Rakić, T., Malenović, A., Ivanović, D.,& Medenica, M.. (2013). Five different columns in the analysis of basic drugs in hydrophilic interaction liquid chromatography. in Central European Journal of Chemistry
Versita, Warsaw., 11(7), 1150-1162.
https://doi.org/10.2478/s11532-013-0245-0

Jovanović M, Jančić-Stojanović B, Rakić T, Malenović A, Ivanović D, Medenica M. Five different columns in the analysis of basic drugs in hydrophilic interaction liquid chromatography. in Central European Journal of Chemistry. 2013;11(7):1150-1162.
doi:10.2478/s11532-013-0245-0 .

Jovanović, Marko, Jančić-Stojanović, Biljana, Rakić, Tijana, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Five different columns in the analysis of basic drugs in hydrophilic interaction liquid chromatography" in Central European Journal of Chemistry, 11, no. 7 (2013):1150-1162,
https://doi.org/10.2478/s11532-013-0245-0 . .

TY  - JOUR
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Jovanović, Marko
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2003
AB  - This paper investigates the ability of seven chromatographic response functions to measure the quality of chromatograms obtained in hydrophilic interaction liquid chromatography (HILIC). First, the functions were tested on a set of simulated chromatograms and differences in their mathematical design were discussed. Second, the functions were evaluated on the experimentally obtained chromatograms in HILIC analysis of model mixture consisted of beta agonists and antagonists. The ranking of chromatograms obtained by different functions was significantly different, implying that the accuracy of the optimization procedure is strongly dependent on the function that was selected as an output. Investigation of potential drawbacks of each function was conducted and general recommendations concerning the use of chromatographic response functions in optimization strategies are proposed.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Analytical Letters
T1  - Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System
VL  - 46
IS  - 8
SP  - 1198
EP  - 1212
DO  - 10.1080/00032719.2012.755689
ER  - 

@article{
author = "Rakić, Tijana and Jančić-Stojanović, Biljana and Jovanović, Marko and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2013",
abstract = "This paper investigates the ability of seven chromatographic response functions to measure the quality of chromatograms obtained in hydrophilic interaction liquid chromatography (HILIC). First, the functions were tested on a set of simulated chromatograms and differences in their mathematical design were discussed. Second, the functions were evaluated on the experimentally obtained chromatograms in HILIC analysis of model mixture consisted of beta agonists and antagonists. The ranking of chromatograms obtained by different functions was significantly different, implying that the accuracy of the optimization procedure is strongly dependent on the function that was selected as an output. Investigation of potential drawbacks of each function was conducted and general recommendations concerning the use of chromatographic response functions in optimization strategies are proposed.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Analytical Letters",
title = "Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System",
volume = "46",
number = "8",
pages = "1198-1212",
doi = "10.1080/00032719.2012.755689"
}

Rakić, T., Jančić-Stojanović, B., Jovanović, M., Malenović, A., Ivanović, D.,& Medenica, M.. (2013). Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System. in Analytical Letters
Taylor & Francis Inc, Philadelphia., 46(8), 1198-1212.
https://doi.org/10.1080/00032719.2012.755689

Rakić T, Jančić-Stojanović B, Jovanović M, Malenović A, Ivanović D, Medenica M. Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System. in Analytical Letters. 2013;46(8):1198-1212.
doi:10.1080/00032719.2012.755689 .

Rakić, Tijana, Jančić-Stojanović, Biljana, Jovanović, Marko, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Evaluation of Seven Chromatographic Response Functions on Simulated and Experimentally Obtained Chromatograms in Hydrophilic Interaction Liquid Chromatography System" in Analytical Letters, 46, no. 8 (2013):1198-1212,
https://doi.org/10.1080/00032719.2012.755689 . .

TY  - JOUR
AU  - Jovanović, Marko
AU  - Jančić-Stojanović, Biljana
PY  - 2013
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1991
AB  - In this paper detailed analysis of a mixture of four amides (tropicamide, nicotinamide, tiracetam, and piracetam) and six sulfonamides (sulfanilamide, sulfacetamide, sulfamethoxazole, sulfafurazole, furosemide, and bumetanide) on aminopropyl column in hydrophilic interaction chromatography (HILIC) was carried out. Since, there are no papers on the topic of the assessment of the contribution of ion-exchange retention mechanism involved in the separation of the acidic compounds on aminopropyl column in HILIC mode, the authors utilized the retention data of the acidic sulfonamides for this purpose. Next, broad range of the aqueous buffer concentrations in the mobile phase was examined providing the separation under either HILIC or RP conditions. Turning points between these two mechanisms were determined and then the fitting of the experimental data in the localized and non-localized adsorption models in both RP and HILIC regions was assessed. Since not many papers in the literature were dealing with the estimation of factor influence on the retention behavior of neutral and acidic compounds on aminopropyl column in HILIC, Box-Behnken design and Response Surface Methodology were applied. On the basis of the obtained data, ten quadratic models were proposed and their adequacy was confirmed using ANOVA test. Furthermore, retention data was graphically evaluated by the construction of 3D response surface plots. Finally, good predictive ability of the suggested models was proved with five additional verification experiments.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Thorough investigation of the retention mechanisms and retention behavior of amides and sulfonamides on amino column in hydrophilic interaction liquid chromatography
VL  - 1301
SP  - 27
EP  - 37
DO  - 10.1016/j.chroma.2013.05.034
ER  - 

@article{
author = "Jovanović, Marko and Jančić-Stojanović, Biljana",
year = "2013",
abstract = "In this paper detailed analysis of a mixture of four amides (tropicamide, nicotinamide, tiracetam, and piracetam) and six sulfonamides (sulfanilamide, sulfacetamide, sulfamethoxazole, sulfafurazole, furosemide, and bumetanide) on aminopropyl column in hydrophilic interaction chromatography (HILIC) was carried out. Since, there are no papers on the topic of the assessment of the contribution of ion-exchange retention mechanism involved in the separation of the acidic compounds on aminopropyl column in HILIC mode, the authors utilized the retention data of the acidic sulfonamides for this purpose. Next, broad range of the aqueous buffer concentrations in the mobile phase was examined providing the separation under either HILIC or RP conditions. Turning points between these two mechanisms were determined and then the fitting of the experimental data in the localized and non-localized adsorption models in both RP and HILIC regions was assessed. Since not many papers in the literature were dealing with the estimation of factor influence on the retention behavior of neutral and acidic compounds on aminopropyl column in HILIC, Box-Behnken design and Response Surface Methodology were applied. On the basis of the obtained data, ten quadratic models were proposed and their adequacy was confirmed using ANOVA test. Furthermore, retention data was graphically evaluated by the construction of 3D response surface plots. Finally, good predictive ability of the suggested models was proved with five additional verification experiments.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Thorough investigation of the retention mechanisms and retention behavior of amides and sulfonamides on amino column in hydrophilic interaction liquid chromatography",
volume = "1301",
pages = "27-37",
doi = "10.1016/j.chroma.2013.05.034"
}

Jovanović, M.,& Jančić-Stojanović, B.. (2013). Thorough investigation of the retention mechanisms and retention behavior of amides and sulfonamides on amino column in hydrophilic interaction liquid chromatography. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1301, 27-37.
https://doi.org/10.1016/j.chroma.2013.05.034

Jovanović M, Jančić-Stojanović B. Thorough investigation of the retention mechanisms and retention behavior of amides and sulfonamides on amino column in hydrophilic interaction liquid chromatography. in Journal of Chromatography A. 2013;1301:27-37.
doi:10.1016/j.chroma.2013.05.034 .

Jovanović, Marko, Jančić-Stojanović, Biljana, "Thorough investigation of the retention mechanisms and retention behavior of amides and sulfonamides on amino column in hydrophilic interaction liquid chromatography" in Journal of Chromatography A, 1301 (2013):27-37,
https://doi.org/10.1016/j.chroma.2013.05.034 . .

TY  - JOUR
AU  - Kasagić-Vujanović, Irena
AU  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1815
AB  - Test of robustness is a part of the method validation and it is carried out in the end of the method development or in the beginning of the method validation. The purpose of robustness testing is to avoid problems in interlaboratory studies and to define parameters with the greatest impact on the method. The chosen factors are investigated within the range that slightly exceeds the expected variations when the method is transferred from one instrument/laboratory to another. The application of experimental design is recommended to perform robustness testing and two most often utilized - Plackett-Burman and fractional factorial design - are described. Furthermore, the manners of evaluation of factor significance, the methods for calculation of the range of insignificance for significant factors and the procedure for determination of system suitability test parameters are described. Such an approach of robustness testing was applied to the high performance liquid chromatographic method for determination of itraconazole and its impurities B and F. The robustness is tested by using fractional factorial design and 4 factors in 11 experiments were analyzed. After the application and the analysis of all the suggested steps for robustness, the impact of factors on the system responses was evaluated, insignificance ranges were defined and system suitability test limits for suggested method were determined.
AB  - Test robusnosti metode predstavlja deo validacije metode, a izvodi se na kraju razvoja metode ili na početku validacije. Testiranje robusnosti je uvedeno da bi se izbegli problemi u međulaboratorijskim ispitivanjima i da bi se definisali faktori koji imaju najveći uticaj na metodu. Izabrani faktori ispituju se u intervalu koji blago prevazilazi varijacije koje se očekuju kada se metoda prenosi sa jednog instrumenta/laboratorije na drugi. Za testiranje robusnosti korisno je primeniti eksperimentalni dizajn. U ovom radu opisana su dva najčešće korišćena, Plakett-Burman-ov i frakcioni faktorski dizajn. Takođe, opisani su i načini procene značajnosti faktora, zatim načini izračunavanja intervala neznačajnosti za značajne faktore, kao i postupak određivanja parametara za procenu pogodnosti sistema. Ovakav pristup procene robusnosti metode primenjen je na metodu tečne hromatografije za određivanje itrakonazola i njegovih nečistoća B i F. Robusnost je testirana primenom frakcionog faktorskog dizajna, a analizirana su četiri faktora kroz 11 eksperimenata. Sprovodeći i analizirajući sve predložene korake za robusnost procenjen je uticaj faktora na faktore rezolucije kao odgovore sistema, definisani su intervali neznačajnosti i određeni limiti za proveru pogodnosti sistema predložene metode.
PB  - Savez farmaceutskih udruženja Srbije, Beograd
T2  - Arhiv za farmaciju
T1  - Robustness testing of liquid chromatographic method for determination of itraconazole and its impurities applying fractional factorial design
T1  - Testiranje robusnosti metode tečne hromatografije za određivanje itrakonazola i njegovih nečistoća primenom frakcionog faktorskog dizajna
VL  - 62
IS  - 5
SP  - 475
EP  - 488
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1815
ER  - 

@article{
author = "Kasagić-Vujanović, Irena and Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana and Ivanović, Darko",
year = "2012",
abstract = "Test of robustness is a part of the method validation and it is carried out in the end of the method development or in the beginning of the method validation. The purpose of robustness testing is to avoid problems in interlaboratory studies and to define parameters with the greatest impact on the method. The chosen factors are investigated within the range that slightly exceeds the expected variations when the method is transferred from one instrument/laboratory to another. The application of experimental design is recommended to perform robustness testing and two most often utilized - Plackett-Burman and fractional factorial design - are described. Furthermore, the manners of evaluation of factor significance, the methods for calculation of the range of insignificance for significant factors and the procedure for determination of system suitability test parameters are described. Such an approach of robustness testing was applied to the high performance liquid chromatographic method for determination of itraconazole and its impurities B and F. The robustness is tested by using fractional factorial design and 4 factors in 11 experiments were analyzed. After the application and the analysis of all the suggested steps for robustness, the impact of factors on the system responses was evaluated, insignificance ranges were defined and system suitability test limits for suggested method were determined., Test robusnosti metode predstavlja deo validacije metode, a izvodi se na kraju razvoja metode ili na početku validacije. Testiranje robusnosti je uvedeno da bi se izbegli problemi u međulaboratorijskim ispitivanjima i da bi se definisali faktori koji imaju najveći uticaj na metodu. Izabrani faktori ispituju se u intervalu koji blago prevazilazi varijacije koje se očekuju kada se metoda prenosi sa jednog instrumenta/laboratorije na drugi. Za testiranje robusnosti korisno je primeniti eksperimentalni dizajn. U ovom radu opisana su dva najčešće korišćena, Plakett-Burman-ov i frakcioni faktorski dizajn. Takođe, opisani su i načini procene značajnosti faktora, zatim načini izračunavanja intervala neznačajnosti za značajne faktore, kao i postupak određivanja parametara za procenu pogodnosti sistema. Ovakav pristup procene robusnosti metode primenjen je na metodu tečne hromatografije za određivanje itrakonazola i njegovih nečistoća B i F. Robusnost je testirana primenom frakcionog faktorskog dizajna, a analizirana su četiri faktora kroz 11 eksperimenata. Sprovodeći i analizirajući sve predložene korake za robusnost procenjen je uticaj faktora na faktore rezolucije kao odgovore sistema, definisani su intervali neznačajnosti i određeni limiti za proveru pogodnosti sistema predložene metode.",
publisher = "Savez farmaceutskih udruženja Srbije, Beograd",
journal = "Arhiv za farmaciju",
title = "Robustness testing of liquid chromatographic method for determination of itraconazole and its impurities applying fractional factorial design, Testiranje robusnosti metode tečne hromatografije za određivanje itrakonazola i njegovih nečistoća primenom frakcionog faktorskog dizajna",
volume = "62",
number = "5",
pages = "475-488",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1815"
}

Kasagić-Vujanović, I., Jovanović, M., Rakić, T., Jančić-Stojanović, B.,& Ivanović, D.. (2012). Robustness testing of liquid chromatographic method for determination of itraconazole and its impurities applying fractional factorial design. in Arhiv za farmaciju
Savez farmaceutskih udruženja Srbije, Beograd., 62(5), 475-488.
https://hdl.handle.net/21.15107/rcub_farfar_1815

Kasagić-Vujanović I, Jovanović M, Rakić T, Jančić-Stojanović B, Ivanović D. Robustness testing of liquid chromatographic method for determination of itraconazole and its impurities applying fractional factorial design. in Arhiv za farmaciju. 2012;62(5):475-488.
https://hdl.handle.net/21.15107/rcub_farfar_1815 .

Kasagić-Vujanović, Irena, Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, Ivanović, Darko, "Robustness testing of liquid chromatographic method for determination of itraconazole and its impurities applying fractional factorial design" in Arhiv za farmaciju, 62, no. 5 (2012):475-488,
https://hdl.handle.net/21.15107/rcub_farfar_1815 .

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  - Jovanović, Marko
AU  - Rakić, Tijana
AU  - Jančić-Stojanović, Biljana
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2012
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1714
AB  - In this paper, the retention prediction models for mixture of beta-lactam antibiotics analyzed by hydrophilic interaction chromatography (HILIC) are presented. The aim of the study was to investigate the retention behavior of some organic acids and amphoteric compounds including cephalosporins (cefotaxime, cefalexin, cefaclor, cefuroxime, and cefuroxime axetil) and penicillins (ampicillin and amoxicillin). Retention of substances with acidic functional group in HILIC is considered to be interesting since the majority of publications in literature are related to basic compounds. In the beginning of the study, classical silica columns were chosen for the retention analysis. Then, preliminary study was done and factors with the most significant influence on the retention factors were selected. These factors with the impact on the retention factors were investigated employing Box-Behnken design as a tool. On the basis of the obtained results the mathematical models were created and tested using ANOVA test and finally verified. This approach enables the presentation of chromatographic retention in many ways (three-dimensional (3-D) graphs and simple two-dimensional graphical presentations). All of these gave the possibility to predict the chromatographic retention under different conditions. Furthermore, regarding the structure of the analyzed compounds, the potential retention mechanisms in HILIC were suggested.
PB  - Wiley-VCH Verlag GMBH, Weinheim
T2  - Journal of Separation Science
T1  - Assessment of beta-lactams retention in hydrophilic interaction chromatography applying Box-Behnken Design
VL  - 35
IS  - 12
SP  - 1424
EP  - 1431
DO  - 10.1002/jssc.201200099
ER  - 

@article{
author = "Jovanović, Marko and Rakić, Tijana and Jančić-Stojanović, Biljana and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2012",
abstract = "In this paper, the retention prediction models for mixture of beta-lactam antibiotics analyzed by hydrophilic interaction chromatography (HILIC) are presented. The aim of the study was to investigate the retention behavior of some organic acids and amphoteric compounds including cephalosporins (cefotaxime, cefalexin, cefaclor, cefuroxime, and cefuroxime axetil) and penicillins (ampicillin and amoxicillin). Retention of substances with acidic functional group in HILIC is considered to be interesting since the majority of publications in literature are related to basic compounds. In the beginning of the study, classical silica columns were chosen for the retention analysis. Then, preliminary study was done and factors with the most significant influence on the retention factors were selected. These factors with the impact on the retention factors were investigated employing Box-Behnken design as a tool. On the basis of the obtained results the mathematical models were created and tested using ANOVA test and finally verified. This approach enables the presentation of chromatographic retention in many ways (three-dimensional (3-D) graphs and simple two-dimensional graphical presentations). All of these gave the possibility to predict the chromatographic retention under different conditions. Furthermore, regarding the structure of the analyzed compounds, the potential retention mechanisms in HILIC were suggested.",
publisher = "Wiley-VCH Verlag GMBH, Weinheim",
journal = "Journal of Separation Science",
title = "Assessment of beta-lactams retention in hydrophilic interaction chromatography applying Box-Behnken Design",
volume = "35",
number = "12",
pages = "1424-1431",
doi = "10.1002/jssc.201200099"
}

Jovanović, M., Rakić, T., Jančić-Stojanović, B., Malenović, A., Ivanović, D.,& Medenica, M.. (2012). Assessment of beta-lactams retention in hydrophilic interaction chromatography applying Box-Behnken Design. in Journal of Separation Science
Wiley-VCH Verlag GMBH, Weinheim., 35(12), 1424-1431.
https://doi.org/10.1002/jssc.201200099

Jovanović M, Rakić T, Jančić-Stojanović B, Malenović A, Ivanović D, Medenica M. Assessment of beta-lactams retention in hydrophilic interaction chromatography applying Box-Behnken Design. in Journal of Separation Science. 2012;35(12):1424-1431.
doi:10.1002/jssc.201200099 .

Jovanović, Marko, Rakić, Tijana, Jančić-Stojanović, Biljana, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Assessment of beta-lactams retention in hydrophilic interaction chromatography applying Box-Behnken Design" in Journal of Separation Science, 35, no. 12 (2012):1424-1431,
https://doi.org/10.1002/jssc.201200099 . .