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

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

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

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

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

TY  - JOUR
AU  - Masković, Marija
AU  - Dotsikas, Yannis
AU  - Malenović, Anđelija
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2011
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1560
AB  - This paper describes the development and validation of a microemulsion liquid chromatography (MELC) method for simultaneous determination of perindopril tert-butylamine and its impurities in bulk active substances and the pharmaceutical dosage form of tablets. An appropriate resolution with reasonable retention times was obtained for a microemulsion containing 0.24% (w/v) butyl acetate, 0.30% (w/v) ethyl acetate, 2% (w/v) sodium dodecyl sulfate, 7.75% (w/v) n-butanol, and 20.0 mM potassium dihydrogen phosphate, the pH of which was adjusted to 3.70 with 85% orthophosphoric acid. Separations were performed on a Nucleosil 120-5 butyl modified (C4), 250 x 4 mm, 5 pm particle size silica column at 40 degrees C, with a mobile phase flow rate of 1.25 mL/min. UV detection was performed at 254 nm. The established method was subjected to method validation, and required validation parameters were defined. Robustness testing, an important part of method validation, was performed as well. Since robustness validation can be conducted using different experimental designs, the Plackett-Burman design was applied due to its possibility of testing many factors at the same time. The validated MELC method was found to be suitable for the simultaneous determination of perindopril tert-butylamine and its impurities in pharmaceuticals.
PB  - AOAC Int, Gaithersburg
T2  - Journal of AOAC International
T1  - Validation of an Oil-in-Water Microemulsion Liquid Chromatography Method for Analysis of Perindopril tert-Butylamine and Its Impurities
VL  - 94
IS  - 3
SP  - 723
EP  - 734
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1560
ER  - 

@article{
author = "Masković, Marija and Dotsikas, Yannis and Malenović, Anđelija and Jančić-Stojanović, Biljana and Ivanović, Darko and Medenica, Mirjana",
year = "2011",
abstract = "This paper describes the development and validation of a microemulsion liquid chromatography (MELC) method for simultaneous determination of perindopril tert-butylamine and its impurities in bulk active substances and the pharmaceutical dosage form of tablets. An appropriate resolution with reasonable retention times was obtained for a microemulsion containing 0.24% (w/v) butyl acetate, 0.30% (w/v) ethyl acetate, 2% (w/v) sodium dodecyl sulfate, 7.75% (w/v) n-butanol, and 20.0 mM potassium dihydrogen phosphate, the pH of which was adjusted to 3.70 with 85% orthophosphoric acid. Separations were performed on a Nucleosil 120-5 butyl modified (C4), 250 x 4 mm, 5 pm particle size silica column at 40 degrees C, with a mobile phase flow rate of 1.25 mL/min. UV detection was performed at 254 nm. The established method was subjected to method validation, and required validation parameters were defined. Robustness testing, an important part of method validation, was performed as well. Since robustness validation can be conducted using different experimental designs, the Plackett-Burman design was applied due to its possibility of testing many factors at the same time. The validated MELC method was found to be suitable for the simultaneous determination of perindopril tert-butylamine and its impurities in pharmaceuticals.",
publisher = "AOAC Int, Gaithersburg",
journal = "Journal of AOAC International",
title = "Validation of an Oil-in-Water Microemulsion Liquid Chromatography Method for Analysis of Perindopril tert-Butylamine and Its Impurities",
volume = "94",
number = "3",
pages = "723-734",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1560"
}

Masković, M., Dotsikas, Y., Malenović, A., Jančić-Stojanović, B., Ivanović, D.,& Medenica, M.. (2011). Validation of an Oil-in-Water Microemulsion Liquid Chromatography Method for Analysis of Perindopril tert-Butylamine and Its Impurities. in Journal of AOAC International
AOAC Int, Gaithersburg., 94(3), 723-734.
https://hdl.handle.net/21.15107/rcub_farfar_1560

Masković M, Dotsikas Y, Malenović A, Jančić-Stojanović B, Ivanović D, Medenica M. Validation of an Oil-in-Water Microemulsion Liquid Chromatography Method for Analysis of Perindopril tert-Butylamine and Its Impurities. in Journal of AOAC International. 2011;94(3):723-734.
https://hdl.handle.net/21.15107/rcub_farfar_1560 .

Masković, Marija, Dotsikas, Yannis, Malenović, Anđelija, Jančić-Stojanović, Biljana, Ivanović, Darko, Medenica, Mirjana, "Validation of an Oil-in-Water Microemulsion Liquid Chromatography Method for Analysis of Perindopril tert-Butylamine and Its Impurities" in Journal of AOAC International, 94, no. 3 (2011):723-734,
https://hdl.handle.net/21.15107/rcub_farfar_1560 .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Malenović, Anđelija
AU  - Marković, Slavko
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2010
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1371
AB  - An RP-HPLC method has been optimized and validated for the simultaneous determination of hydrocortisone acetate and of lidocaine in suppositories. For the method optimization, response surface methodology was applied, and the obtained model was tested using analysis of variance. The optimal separations were conducted on a Beckman-Coulter 150 x 4.6 mm, 5 pm particle-size column at 20 degrees C. The mobile phase was methanol-water (65 + 35, v/v), pH adjusted to 2.5 with 85% orthophosphoric acid, with a flow rate of 1.0 mL/min. UV detection was performed at 250 nm. Phenobarbital was used as an internal standard. The method was validated for selectivity, linearity, precision, and robustness.
PB  - AOAC Int, Gaithersburg
T2  - Journal of AOAC International
T1  - Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories
VL  - 93
IS  - 1
SP  - 102
EP  - 107
DO  - 10.1093/jaoac/93.1.102
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1371
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Malenović, Anđelija and Marković, Slavko and Ivanović, Darko and Medenica, Mirjana",
year = "2010",
abstract = "An RP-HPLC method has been optimized and validated for the simultaneous determination of hydrocortisone acetate and of lidocaine in suppositories. For the method optimization, response surface methodology was applied, and the obtained model was tested using analysis of variance. The optimal separations were conducted on a Beckman-Coulter 150 x 4.6 mm, 5 pm particle-size column at 20 degrees C. The mobile phase was methanol-water (65 + 35, v/v), pH adjusted to 2.5 with 85% orthophosphoric acid, with a flow rate of 1.0 mL/min. UV detection was performed at 250 nm. Phenobarbital was used as an internal standard. The method was validated for selectivity, linearity, precision, and robustness.",
publisher = "AOAC Int, Gaithersburg",
journal = "Journal of AOAC International",
title = "Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories",
volume = "93",
number = "1",
pages = "102-107",
doi = "10.1093/jaoac/93.1.102",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1371"
}

Jančić-Stojanović, B., Malenović, A., Marković, S., Ivanović, D.,& Medenica, M.. (2010). Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories. in Journal of AOAC International
AOAC Int, Gaithersburg., 93(1), 102-107.
https://doi.org/10.1093/jaoac/93.1.102
https://hdl.handle.net/21.15107/rcub_farfar_1371

Jančić-Stojanović B, Malenović A, Marković S, Ivanović D, Medenica M. Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories. in Journal of AOAC International. 2010;93(1):102-107.
doi:10.1093/jaoac/93.1.102
https://hdl.handle.net/21.15107/rcub_farfar_1371 .

Jančić-Stojanović, Biljana, Malenović, Anđelija, Marković, Slavko, Ivanović, Darko, Medenica, Mirjana, "Optimization and Validation of an RP-HPLC Method for Analysis of Hydrocortisone Acetate and Lidocaine in Suppositories" in Journal of AOAC International, 93, no. 1 (2010):102-107,
https://doi.org/10.1093/jaoac/93.1.102 .,
https://hdl.handle.net/21.15107/rcub_farfar_1371 .

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

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

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

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

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

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Popović, Igor
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2010
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1416
AB  - In this paper optimization of chromatographic retention of ramipril and its five impurities employing factorial design is presented. On the basis of preliminary experiments three factors were chosen as inputs (acetonitrile content, pH of the mobile phase and buffer concentration) and retention factor as output. As optimal full factorial design 2(3) was chosen, factors were examined at two different levels "low" and "high". Three replications at zero level were added in order to check linearity and complete statistical tests. Relationship between inputs and output is presented in form of second order interaction model. Adequacy of model was explained using analysis of variance. After analysis of results optimal chromatographic conditions were set. Separations were conducted on a C(18) column with a mixture of acetonitrile and water phase (TEA in potassium dihydrogen phosphate) in ratio 23:77 v/v. Finally, the LC method was validated and applied for quality control analysis of commercially available tablets. The proposed method is simpler and faster as compared to existing official methods and therefore more adequate for routine control of ramipril during shelf life. Also a general approach which includes factorial design in method optimization offers a possibility for predicting and following the chromatographic behavior of such complex mixtures.
PB  - Springer Heidelberg, Heidelberg
T2  - Chromatographia
T1  - Factorial Design in Optimization of Chromatographic Separation of Ramipril and Its Impurities
VL  - 71
IS  - 9-10
SP  - 799
EP  - 804
DO  - 10.1365/s10337-010-1546-5
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Popović, Igor and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2010",
abstract = "In this paper optimization of chromatographic retention of ramipril and its five impurities employing factorial design is presented. On the basis of preliminary experiments three factors were chosen as inputs (acetonitrile content, pH of the mobile phase and buffer concentration) and retention factor as output. As optimal full factorial design 2(3) was chosen, factors were examined at two different levels "low" and "high". Three replications at zero level were added in order to check linearity and complete statistical tests. Relationship between inputs and output is presented in form of second order interaction model. Adequacy of model was explained using analysis of variance. After analysis of results optimal chromatographic conditions were set. Separations were conducted on a C(18) column with a mixture of acetonitrile and water phase (TEA in potassium dihydrogen phosphate) in ratio 23:77 v/v. Finally, the LC method was validated and applied for quality control analysis of commercially available tablets. The proposed method is simpler and faster as compared to existing official methods and therefore more adequate for routine control of ramipril during shelf life. Also a general approach which includes factorial design in method optimization offers a possibility for predicting and following the chromatographic behavior of such complex mixtures.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Chromatographia",
title = "Factorial Design in Optimization of Chromatographic Separation of Ramipril and Its Impurities",
volume = "71",
number = "9-10",
pages = "799-804",
doi = "10.1365/s10337-010-1546-5"
}

Jančić-Stojanović, B., Popović, I., Malenović, A., Ivanović, D.,& Medenica, M.. (2010). Factorial Design in Optimization of Chromatographic Separation of Ramipril and Its Impurities. in Chromatographia
Springer Heidelberg, Heidelberg., 71(9-10), 799-804.
https://doi.org/10.1365/s10337-010-1546-5

Jančić-Stojanović B, Popović I, Malenović A, Ivanović D, Medenica M. Factorial Design in Optimization of Chromatographic Separation of Ramipril and Its Impurities. in Chromatographia. 2010;71(9-10):799-804.
doi:10.1365/s10337-010-1546-5 .

Jančić-Stojanović, Biljana, Popović, Igor, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Factorial Design in Optimization of Chromatographic Separation of Ramipril and Its Impurities" in Chromatographia, 71, no. 9-10 (2010):799-804,
https://doi.org/10.1365/s10337-010-1546-5 . .

TY  - JOUR
AU  - Masković, M.
AU  - Jančić-Stojanović, Biljana
AU  - Malenović, Anđelija
AU  - Ivanović, D.
AU  - Medenica, Mirjana
PY  - 2010
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1399
AB  - Robustness testing is an important part of method validation. Many ideas on robustness testing can be found in the literature, but the most useful approach is application of experimental design. In the work discussed in this paper, Plackett-Burman design was used for robustness testing of an LC method. Robustness was assessed for a previously validated method developed for chromatographic analysis of perindopril tert-butylamine and its impurities. Eleven factors (seven real and four dummies) in twelve experiments were examined. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. For estimation of the standard error of effect (necessary for t-test estimation) calculations based on negligible effects and Dong's algorithm were used at the significance levels alpha = 0.05 and alpha = 0.01. In this way the effect of the factors was completely defined and, furthermore, nonsignificant intervals for significant variables were calculated. Finally, on the basis of the worst-case situation, system-suitability tests were performed and acceptance limits for certain values were calculated.
PB  - Akademiai Kiado Zrt, Budapest
T2  - Acta Chromatographica
T1  - Assessment of Liquid Chromatographic Method Robustness by Use of Plackett-Burman Design
VL  - 22
IS  - 2
SP  - 281
EP  - 296
DO  - 10.1556/AChrom.22.2010.2.10
ER  - 

@article{
author = "Masković, M. and Jančić-Stojanović, Biljana and Malenović, Anđelija and Ivanović, D. and Medenica, Mirjana",
year = "2010",
abstract = "Robustness testing is an important part of method validation. Many ideas on robustness testing can be found in the literature, but the most useful approach is application of experimental design. In the work discussed in this paper, Plackett-Burman design was used for robustness testing of an LC method. Robustness was assessed for a previously validated method developed for chromatographic analysis of perindopril tert-butylamine and its impurities. Eleven factors (seven real and four dummies) in twelve experiments were examined. Robustness was assessed by graphical (half-normal probability plots and Pareto charts) and statistical (t-test) methods. For estimation of the standard error of effect (necessary for t-test estimation) calculations based on negligible effects and Dong's algorithm were used at the significance levels alpha = 0.05 and alpha = 0.01. In this way the effect of the factors was completely defined and, furthermore, nonsignificant intervals for significant variables were calculated. Finally, on the basis of the worst-case situation, system-suitability tests were performed and acceptance limits for certain values were calculated.",
publisher = "Akademiai Kiado Zrt, Budapest",
journal = "Acta Chromatographica",
title = "Assessment of Liquid Chromatographic Method Robustness by Use of Plackett-Burman Design",
volume = "22",
number = "2",
pages = "281-296",
doi = "10.1556/AChrom.22.2010.2.10"
}

Masković, M., Jančić-Stojanović, B., Malenović, A., Ivanović, D.,& Medenica, M.. (2010). Assessment of Liquid Chromatographic Method Robustness by Use of Plackett-Burman Design. in Acta Chromatographica
Akademiai Kiado Zrt, Budapest., 22(2), 281-296.
https://doi.org/10.1556/AChrom.22.2010.2.10

Masković M, Jančić-Stojanović B, Malenović A, Ivanović D, Medenica M. Assessment of Liquid Chromatographic Method Robustness by Use of Plackett-Burman Design. in Acta Chromatographica. 2010;22(2):281-296.
doi:10.1556/AChrom.22.2010.2.10 .

Masković, M., Jančić-Stojanović, Biljana, Malenović, Anđelija, Ivanović, D., Medenica, Mirjana, "Assessment of Liquid Chromatographic Method Robustness by Use of Plackett-Burman Design" in Acta Chromatographica, 22, no. 2 (2010):281-296,
https://doi.org/10.1556/AChrom.22.2010.2.10 . .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2010
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1389
AB  - In this paper, the definition of simvastatin degradation profile by microemulsion liquid chromatography (MELC) is presented. The aim of the study was to investigate simvastatin stability after various stress tests, such as: acid and base hydrolysis, oxidation, and heat. The kinetics of acid and oxidative degradation was also studied. The complex retention mechanism occurring when microemulsion is used as eluent enabled the successful separation of a large number of degradants in prepared stress samples. The existence of a second partitioning site due to microstructural and interfacial characteristics of o/w microemulsion eluent facilitated HPLC separation. All the expected capabilities of MELC method were realized, demonstrating the advantage and value of the MELC method for a wide area of pharmaceutical analysis. For acid degradation the second order rate constant and half-life were calculated. Oxidative decomposition proved to be the first order reaction for which the rate constant and half-life were also determined.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Liquid Chromatography & Related Technologies
T1  - Forced degradation studies of simvastatin using microemulsion liquid chromatography
VL  - 33
IS  - 4
SP  - 536
EP  - 547
DO  - 10.1080/10826070903574576
ER  - 

@article{
author = "Malenović, Anđelija and Jančić-Stojanović, Biljana and Ivanović, Darko and Medenica, Mirjana",
year = "2010",
abstract = "In this paper, the definition of simvastatin degradation profile by microemulsion liquid chromatography (MELC) is presented. The aim of the study was to investigate simvastatin stability after various stress tests, such as: acid and base hydrolysis, oxidation, and heat. The kinetics of acid and oxidative degradation was also studied. The complex retention mechanism occurring when microemulsion is used as eluent enabled the successful separation of a large number of degradants in prepared stress samples. The existence of a second partitioning site due to microstructural and interfacial characteristics of o/w microemulsion eluent facilitated HPLC separation. All the expected capabilities of MELC method were realized, demonstrating the advantage and value of the MELC method for a wide area of pharmaceutical analysis. For acid degradation the second order rate constant and half-life were calculated. Oxidative decomposition proved to be the first order reaction for which the rate constant and half-life were also determined.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Liquid Chromatography & Related Technologies",
title = "Forced degradation studies of simvastatin using microemulsion liquid chromatography",
volume = "33",
number = "4",
pages = "536-547",
doi = "10.1080/10826070903574576"
}

Malenović, A., Jančić-Stojanović, B., Ivanović, D.,& Medenica, M.. (2010). Forced degradation studies of simvastatin using microemulsion liquid chromatography. in Journal of Liquid Chromatography & Related Technologies
Taylor & Francis Inc, Philadelphia., 33(4), 536-547.
https://doi.org/10.1080/10826070903574576

Malenović A, Jančić-Stojanović B, Ivanović D, Medenica M. Forced degradation studies of simvastatin using microemulsion liquid chromatography. in Journal of Liquid Chromatography & Related Technologies. 2010;33(4):536-547.
doi:10.1080/10826070903574576 .

Malenović, Anđelija, Jančić-Stojanović, Biljana, Ivanović, Darko, Medenica, Mirjana, "Forced degradation studies of simvastatin using microemulsion liquid chromatography" in Journal of Liquid Chromatography & Related Technologies, 33, no. 4 (2010):536-547,
https://doi.org/10.1080/10826070903574576 . .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1275
AB  - In past few years, for overcoming some analytical problems in liquid chromatography, the microemulsion as eluent was employed. Due to the strict regulatory requirements, robustness testing became important especially when proposing completely new method such as microemulsion liquid chromatography (MELC). In this paper robustness testing of MELC method, proposed for carbamazepine and its impurities (iminostilben and iminodibenzyl) separation, was done using two different approaches both based on experiments defined using central composite design (CCD). Input and output data from CCD were either handled as second order polynomials and tested with Analysis of variance (ANOVA), or as variables in Artificial Neural Networks (ANN). From both approaches appropriate conclusions about system robustness were distinguished, e. g. that the influence of surfactant content on chromatographic retention was the largest for all analytes, meaning that small changes in its concentration will strongly influenced on chromatographic retention. On the other hand influence of the pH of the mobile phase proved to be negligible, meaning that the substances are mainly distributed in the interfacial layer. ANN gave better results and proved to be better tool for explanation and understanding of investigated factors effects on the chromatographic system and for definition of the robustness limits.
PB  - Slovensko Kemijsko Drustvo, Ljubljana
T2  - Acta Chimica Slovenica
T1  - Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing
VL  - 56
IS  - 2
SP  - 507
EP  - 512
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1275
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Malenović, Anđelija and Ivanović, Darko and Medenica, Mirjana",
year = "2009",
abstract = "In past few years, for overcoming some analytical problems in liquid chromatography, the microemulsion as eluent was employed. Due to the strict regulatory requirements, robustness testing became important especially when proposing completely new method such as microemulsion liquid chromatography (MELC). In this paper robustness testing of MELC method, proposed for carbamazepine and its impurities (iminostilben and iminodibenzyl) separation, was done using two different approaches both based on experiments defined using central composite design (CCD). Input and output data from CCD were either handled as second order polynomials and tested with Analysis of variance (ANOVA), or as variables in Artificial Neural Networks (ANN). From both approaches appropriate conclusions about system robustness were distinguished, e. g. that the influence of surfactant content on chromatographic retention was the largest for all analytes, meaning that small changes in its concentration will strongly influenced on chromatographic retention. On the other hand influence of the pH of the mobile phase proved to be negligible, meaning that the substances are mainly distributed in the interfacial layer. ANN gave better results and proved to be better tool for explanation and understanding of investigated factors effects on the chromatographic system and for definition of the robustness limits.",
publisher = "Slovensko Kemijsko Drustvo, Ljubljana",
journal = "Acta Chimica Slovenica",
title = "Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing",
volume = "56",
number = "2",
pages = "507-512",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1275"
}

Jančić-Stojanović, B., Malenović, A., Ivanović, D.,& Medenica, M.. (2009). Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing. in Acta Chimica Slovenica
Slovensko Kemijsko Drustvo, Ljubljana., 56(2), 507-512.
https://hdl.handle.net/21.15107/rcub_farfar_1275

Jančić-Stojanović B, Malenović A, Ivanović D, Medenica M. Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing. in Acta Chimica Slovenica. 2009;56(2):507-512.
https://hdl.handle.net/21.15107/rcub_farfar_1275 .

Jančić-Stojanović, Biljana, Malenović, Anđelija, Ivanović, Darko, Medenica, Mirjana, "Central Composite Design with/without Artificial Neural Networks in Microemulsion Liquid Chromatography Separation Robustness Testing" in Acta Chimica Slovenica, 56, no. 2 (2009):507-512,
https://hdl.handle.net/21.15107/rcub_farfar_1275 .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Malenović, Anđelija
AU  - Ivanović, D.
AU  - Rakić, Tijana
AU  - Medenica, Mirjana
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1250
AB  - The aim of this study was the chemometrical evaluation of ropinirole and its impurity's (4-[2(dipropylamino)ethyl]-1H-indol-2,3-dione) chromatographic behavior in systematic and the most efficient way. For that purpose, as very descriptive, response surface designs are most preferable. Face-centered central composite design (CCD) with 2(3) full factorial design, +/- 1 star design and four replication in central point was applied for a response surface study, in order to examine in depth the effects of the most important factors. Factors-independent variables (acetonitrile content, pH of the mobile phase and concentration of sodium heptane sulfonate in water phase) were extracted from the preliminary study and as dependent variables five responses (retention factor of ropinirole, retentin factor of its impurity, resolution, symmetry of ropinirole peak and symmetry of impurity peak) were selected. For the improvement of method development and optimization step, Derringer's desirability function was applied to simultaneously optimize the five chosen responses. The procedure allowed deduction of optimal conditions and the predicted optimum was acetonitrile-5 mM of sodium heptane sulfonate (21.6:78.4, v/v), pH of the mobile phase adjusted at 2.0 with ortho phosphoric acid. By calculating global desirability's determination coefficients (R-D(2)), as well as by the visual inspection of 3D graphs for global desirability, robustness of the proposed method was also estimated.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Chemometrical evaluation of ropinirole and its impurity's chromatographic behavior
VL  - 1216
IS  - 8
SP  - 1263
EP  - 1269
DO  - 10.1016/j.chroma.2008.10.059
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Malenović, Anđelija and Ivanović, D. and Rakić, Tijana and Medenica, Mirjana",
year = "2009",
abstract = "The aim of this study was the chemometrical evaluation of ropinirole and its impurity's (4-[2(dipropylamino)ethyl]-1H-indol-2,3-dione) chromatographic behavior in systematic and the most efficient way. For that purpose, as very descriptive, response surface designs are most preferable. Face-centered central composite design (CCD) with 2(3) full factorial design, +/- 1 star design and four replication in central point was applied for a response surface study, in order to examine in depth the effects of the most important factors. Factors-independent variables (acetonitrile content, pH of the mobile phase and concentration of sodium heptane sulfonate in water phase) were extracted from the preliminary study and as dependent variables five responses (retention factor of ropinirole, retentin factor of its impurity, resolution, symmetry of ropinirole peak and symmetry of impurity peak) were selected. For the improvement of method development and optimization step, Derringer's desirability function was applied to simultaneously optimize the five chosen responses. The procedure allowed deduction of optimal conditions and the predicted optimum was acetonitrile-5 mM of sodium heptane sulfonate (21.6:78.4, v/v), pH of the mobile phase adjusted at 2.0 with ortho phosphoric acid. By calculating global desirability's determination coefficients (R-D(2)), as well as by the visual inspection of 3D graphs for global desirability, robustness of the proposed method was also estimated.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Chemometrical evaluation of ropinirole and its impurity's chromatographic behavior",
volume = "1216",
number = "8",
pages = "1263-1269",
doi = "10.1016/j.chroma.2008.10.059"
}

Jančić-Stojanović, B., Malenović, A., Ivanović, D., Rakić, T.,& Medenica, M.. (2009). Chemometrical evaluation of ropinirole and its impurity's chromatographic behavior. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1216(8), 1263-1269.
https://doi.org/10.1016/j.chroma.2008.10.059

Jančić-Stojanović B, Malenović A, Ivanović D, Rakić T, Medenica M. Chemometrical evaluation of ropinirole and its impurity's chromatographic behavior. in Journal of Chromatography A. 2009;1216(8):1263-1269.
doi:10.1016/j.chroma.2008.10.059 .

Jančić-Stojanović, Biljana, Malenović, Anđelija, Ivanović, D., Rakić, Tijana, Medenica, Mirjana, "Chemometrical evaluation of ropinirole and its impurity's chromatographic behavior" in Journal of Chromatography A, 1216, no. 8 (2009):1263-1269,
https://doi.org/10.1016/j.chroma.2008.10.059 . .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Ivanović, Darko
AU  - Jančić-Stojanović, Biljana
AU  - Medenica, Mirjana
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1248
AB  - Liquid chromatography employing the microemulsion as eluent was applied for the analysis of simvastatin and its six impurities. Previously, the optimized and validated method was tested to prove the method's capability to perform during the small changes of important parameters. In this paper, influence of parameters tipical for microemulsion liquid chromatography (MELC) on the method's robustness was presented. For the results evaluation, and presentation, two statistical methods were applied. In order to designate the most convinient one, multiple regression (MR) and artificial neural networks (ANN) were applied and compared. A set of experiments was defined by the central composite design (CCD). Indepedent variables (SDS, n-buthanol and diisopropyl ether content) and dependent variables (retention factors of investigated substances) were the framework for both, MR and ANN. This study demonstrated that MR and radial basis function ANN are useful tools in understanding the effects of the investigated factors on the chromatographic system and definition of the robustness limits.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Liquid Chromatography & Related Technologies
T1  - Robustness Testing of Microemulsion Liquid Chromatographic Separation of Simvastatin and its Impurities
VL  - 32
IS  - 6
SP  - 874
EP  - 889
DO  - 10.1080/10826070902768161
ER  - 

@article{
author = "Malenović, Anđelija and Ivanović, Darko and Jančić-Stojanović, Biljana and Medenica, Mirjana",
year = "2009",
abstract = "Liquid chromatography employing the microemulsion as eluent was applied for the analysis of simvastatin and its six impurities. Previously, the optimized and validated method was tested to prove the method's capability to perform during the small changes of important parameters. In this paper, influence of parameters tipical for microemulsion liquid chromatography (MELC) on the method's robustness was presented. For the results evaluation, and presentation, two statistical methods were applied. In order to designate the most convinient one, multiple regression (MR) and artificial neural networks (ANN) were applied and compared. A set of experiments was defined by the central composite design (CCD). Indepedent variables (SDS, n-buthanol and diisopropyl ether content) and dependent variables (retention factors of investigated substances) were the framework for both, MR and ANN. This study demonstrated that MR and radial basis function ANN are useful tools in understanding the effects of the investigated factors on the chromatographic system and definition of the robustness limits.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Liquid Chromatography & Related Technologies",
title = "Robustness Testing of Microemulsion Liquid Chromatographic Separation of Simvastatin and its Impurities",
volume = "32",
number = "6",
pages = "874-889",
doi = "10.1080/10826070902768161"
}

Malenović, A., Ivanović, D., Jančić-Stojanović, B.,& Medenica, M.. (2009). Robustness Testing of Microemulsion Liquid Chromatographic Separation of Simvastatin and its Impurities. in Journal of Liquid Chromatography & Related Technologies
Taylor & Francis Inc, Philadelphia., 32(6), 874-889.
https://doi.org/10.1080/10826070902768161

Malenović A, Ivanović D, Jančić-Stojanović B, Medenica M. Robustness Testing of Microemulsion Liquid Chromatographic Separation of Simvastatin and its Impurities. in Journal of Liquid Chromatography & Related Technologies. 2009;32(6):874-889.
doi:10.1080/10826070902768161 .

Malenović, Anđelija, Ivanović, Darko, Jančić-Stojanović, Biljana, Medenica, Mirjana, "Robustness Testing of Microemulsion Liquid Chromatographic Separation of Simvastatin and its Impurities" in Journal of Liquid Chromatography & Related Technologies, 32, no. 6 (2009):874-889,
https://doi.org/10.1080/10826070902768161 . .

TY  - JOUR
AU  - Jančić-Stojanović, Biljana
AU  - Ivanović, D.
AU  - Malenović, Anđelija
AU  - Medenica, Mirjana
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1247
AB  - Artificial neural networks (ANN) are biologically inspired computer programs designed to simulate the way in which the human brain processes the information. In the past few years, coupling of experimental design (ED) and ANN became useful tool in the method optimization. This paper presents the application of ED-ANN in analysis of chromatographic behavior of indinavir and its degradation products. According to preliminary study, full factorial design 2(4) was chosen to set input variables for network training. Experimental data (inputs) and results for retention factors from experiments (outputs) were used to train the ANN with aim to define correlation among variables. For networks training multi-layer perceptron (MLP) with back propagation (BP) algorithm was used. Network with the lowest root mean square (RMS) had 4-8-3 topology. Predicted data were in good agreement with experimental data (correlation was higher than 0.9713 for training set). Regression statistics confirmed good ability of trained network to predict compounds retention.
PB  - Elsevier Science BV, Amsterdam
T2  - Talanta
T1  - Artificial neural networks in analysis of indinavir and its degradation products retention
VL  - 78
IS  - 1
SP  - 107
EP  - 112
DO  - 10.1016/j.talanta.2008.10.066
ER  - 

@article{
author = "Jančić-Stojanović, Biljana and Ivanović, D. and Malenović, Anđelija and Medenica, Mirjana",
year = "2009",
abstract = "Artificial neural networks (ANN) are biologically inspired computer programs designed to simulate the way in which the human brain processes the information. In the past few years, coupling of experimental design (ED) and ANN became useful tool in the method optimization. This paper presents the application of ED-ANN in analysis of chromatographic behavior of indinavir and its degradation products. According to preliminary study, full factorial design 2(4) was chosen to set input variables for network training. Experimental data (inputs) and results for retention factors from experiments (outputs) were used to train the ANN with aim to define correlation among variables. For networks training multi-layer perceptron (MLP) with back propagation (BP) algorithm was used. Network with the lowest root mean square (RMS) had 4-8-3 topology. Predicted data were in good agreement with experimental data (correlation was higher than 0.9713 for training set). Regression statistics confirmed good ability of trained network to predict compounds retention.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Talanta",
title = "Artificial neural networks in analysis of indinavir and its degradation products retention",
volume = "78",
number = "1",
pages = "107-112",
doi = "10.1016/j.talanta.2008.10.066"
}

Jančić-Stojanović, B., Ivanović, D., Malenović, A.,& Medenica, M.. (2009). Artificial neural networks in analysis of indinavir and its degradation products retention. in Talanta
Elsevier Science BV, Amsterdam., 78(1), 107-112.
https://doi.org/10.1016/j.talanta.2008.10.066

Jančić-Stojanović B, Ivanović D, Malenović A, Medenica M. Artificial neural networks in analysis of indinavir and its degradation products retention. in Talanta. 2009;78(1):107-112.
doi:10.1016/j.talanta.2008.10.066 .

Jančić-Stojanović, Biljana, Ivanović, D., Malenović, Anđelija, Medenica, Mirjana, "Artificial neural networks in analysis of indinavir and its degradation products retention" in Talanta, 78, no. 1 (2009):107-112,
https://doi.org/10.1016/j.talanta.2008.10.066 . .

TY  - JOUR
AU  - Medenica, Mirjana
AU  - Ivanović, Darko
AU  - Popović, Igor
AU  - Malenović, Anđelija
AU  - Jančić, Biljana
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1075
PB  - Preston Publ Inc, Niles
T2  - Journal of Chromatographic Science
T1  - Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities
VL  - 46
IS  - 5
SP  - 430
EP  - 435
DO  - 10.1093/chromsci/46.5.430
ER  - 

@article{
author = "Medenica, Mirjana and Ivanović, Darko and Popović, Igor and Malenović, Anđelija and Jančić, Biljana",
year = "2008",
publisher = "Preston Publ Inc, Niles",
journal = "Journal of Chromatographic Science",
title = "Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities",
volume = "46",
number = "5",
pages = "430-435",
doi = "10.1093/chromsci/46.5.430"
}

Medenica, M., Ivanović, D., Popović, I., Malenović, A.,& Jančić, B.. (2008). Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities. in Journal of Chromatographic Science
Preston Publ Inc, Niles., 46(5), 430-435.
https://doi.org/10.1093/chromsci/46.5.430

Medenica M, Ivanović D, Popović I, Malenović A, Jančić B. Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities. in Journal of Chromatographic Science. 2008;46(5):430-435.
doi:10.1093/chromsci/46.5.430 .

Medenica, Mirjana, Ivanović, Darko, Popović, Igor, Malenović, Anđelija, Jančić, Biljana, "Computer-assisted optimization and validation of LC analysis of trimetazidine dihydrochloride and its impurities" in Journal of Chromatographic Science, 46, no. 5 (2008):430-435,
https://doi.org/10.1093/chromsci/46.5.430 . .

TY  - JOUR
AU  - Jančić, Biljana
AU  - Medenica, Mirjana
AU  - Ivanović, Darko
AU  - Malenović, Anđelija
AU  - Popović, Igor
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1070
AB  - In this paper, the chromatographic characterization of fosinopril sodium and fosinoprilat is presented. The first stept was pK(a) determination for the active substance and its degradation product using RP-LC. It was followed by optimization employing the combination of experimental design and artificial neural networks. For the definition of input and output variables, the central composite design for three factors was built. Back propagation algorithm was applied to model the system, and then the optimization of the experimental conditions was carried out in the neural network with 3-8-2 structure, which confirmed to be able to provide the maximum performance. From the method optimization, the most appropriate experimental conditions for fosinopril sodium and fosinoprilat analysis were extracted. The optimized method was validated and applied in the quality control of tablets and for forced degradation studies.
PB  - Springer Heidelberg, Heidelberg
T2  - Chromatographia
T1  - Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks
VL  - 67
DO  - 10.1365/s10337-008-0575-9
ER  - 

@article{
author = "Jančić, Biljana and Medenica, Mirjana and Ivanović, Darko and Malenović, Anđelija and Popović, Igor",
year = "2008",
abstract = "In this paper, the chromatographic characterization of fosinopril sodium and fosinoprilat is presented. The first stept was pK(a) determination for the active substance and its degradation product using RP-LC. It was followed by optimization employing the combination of experimental design and artificial neural networks. For the definition of input and output variables, the central composite design for three factors was built. Back propagation algorithm was applied to model the system, and then the optimization of the experimental conditions was carried out in the neural network with 3-8-2 structure, which confirmed to be able to provide the maximum performance. From the method optimization, the most appropriate experimental conditions for fosinopril sodium and fosinoprilat analysis were extracted. The optimized method was validated and applied in the quality control of tablets and for forced degradation studies.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Chromatographia",
title = "Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks",
volume = "67",
doi = "10.1365/s10337-008-0575-9"
}

Jančić, B., Medenica, M., Ivanović, D., Malenović, A.,& Popović, I.. (2008). Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks. in Chromatographia
Springer Heidelberg, Heidelberg., 67.
https://doi.org/10.1365/s10337-008-0575-9

Jančić B, Medenica M, Ivanović D, Malenović A, Popović I. Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks. in Chromatographia. 2008;67.
doi:10.1365/s10337-008-0575-9 .

Jančić, Biljana, Medenica, Mirjana, Ivanović, Darko, Malenović, Anđelija, Popović, Igor, "Chromatographic behavior of fosinopril sodium and fosinoprilat using neural networks" in Chromatographia, 67 (2008),
https://doi.org/10.1365/s10337-008-0575-9 . .

TY  - JOUR
AU  - Jančić, Biljana
AU  - Medenica, Mirjana
AU  - Ivanović, D.
AU  - Janković, Saša
AU  - Malenović, Anđelija
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1068
AB  - In this paper, the mass spectrometry (MS) detection has been applied for screening of fosinopril sodium impurities which arise during forced stress study. Before MS analysis, liquid chromatographic method with suitable mobile phase composition was developed. The separation was done on SunFire 100 turn x 4.6 mm 3.5 mu m particle size column. The mobile phases which consisted of methanol-ammonium acetate buffer-acetic acid, in different ratios, were used in a preliminary study. Flow rate was 0.3 mL min(-1). Under these conditions, percent of methanol, concentration of ammonium acetate buffer and acetic acid content were tested simultaneously applying central composite design (CCD) and artificial neural network (ANN). The combinations of experimental design (ED) and ANN present powerful technique in method optimization. Input and output variables from CCD were used for network training, verification and testing. Multiple layer perceptron (MLP) with back propagation (BP) algorithm was chosen for network training. When the optimal neural topology was selected, network was trained by adjusting strength of connections between neurons in order to adapt the outputs of whole network to be closer to the desired outputs, or to minimize the sum of the squared errors. From the method optimization the following mobile phase composition was selected as appropriate: methanol-10 mM ammonium acetate buffer-acidic acid (80:19.5:0.5 v/v/v). This mobile phase was used as inlet for MS. According to molecular structure and literature data, electrospray positive ion mode was applied for analysis of fosinopril sodium and its impurities. The proposed method could be used for screening of fosinopril sodium impurities in bulk and pharmaceuticals, as well as for tracking the degradation under stress conditions.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Monitoring of fosinopril sodium impurities by liquid chromatography-mass spectrometry including the neural networks in method evaluation
VL  - 1189
IS  - 1-2
SP  - 366
EP  - 373
DO  - 10.1016/j.chroma.2007.11.076
ER  - 

@article{
author = "Jančić, Biljana and Medenica, Mirjana and Ivanović, D. and Janković, Saša and Malenović, Anđelija",
year = "2008",
abstract = "In this paper, the mass spectrometry (MS) detection has been applied for screening of fosinopril sodium impurities which arise during forced stress study. Before MS analysis, liquid chromatographic method with suitable mobile phase composition was developed. The separation was done on SunFire 100 turn x 4.6 mm 3.5 mu m particle size column. The mobile phases which consisted of methanol-ammonium acetate buffer-acetic acid, in different ratios, were used in a preliminary study. Flow rate was 0.3 mL min(-1). Under these conditions, percent of methanol, concentration of ammonium acetate buffer and acetic acid content were tested simultaneously applying central composite design (CCD) and artificial neural network (ANN). The combinations of experimental design (ED) and ANN present powerful technique in method optimization. Input and output variables from CCD were used for network training, verification and testing. Multiple layer perceptron (MLP) with back propagation (BP) algorithm was chosen for network training. When the optimal neural topology was selected, network was trained by adjusting strength of connections between neurons in order to adapt the outputs of whole network to be closer to the desired outputs, or to minimize the sum of the squared errors. From the method optimization the following mobile phase composition was selected as appropriate: methanol-10 mM ammonium acetate buffer-acidic acid (80:19.5:0.5 v/v/v). This mobile phase was used as inlet for MS. According to molecular structure and literature data, electrospray positive ion mode was applied for analysis of fosinopril sodium and its impurities. The proposed method could be used for screening of fosinopril sodium impurities in bulk and pharmaceuticals, as well as for tracking the degradation under stress conditions.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Monitoring of fosinopril sodium impurities by liquid chromatography-mass spectrometry including the neural networks in method evaluation",
volume = "1189",
number = "1-2",
pages = "366-373",
doi = "10.1016/j.chroma.2007.11.076"
}

Jančić, B., Medenica, M., Ivanović, D., Janković, S.,& Malenović, A.. (2008). Monitoring of fosinopril sodium impurities by liquid chromatography-mass spectrometry including the neural networks in method evaluation. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1189(1-2), 366-373.
https://doi.org/10.1016/j.chroma.2007.11.076

Jančić B, Medenica M, Ivanović D, Janković S, Malenović A. Monitoring of fosinopril sodium impurities by liquid chromatography-mass spectrometry including the neural networks in method evaluation. in Journal of Chromatography A. 2008;1189(1-2):366-373.
doi:10.1016/j.chroma.2007.11.076 .

Jančić, Biljana, Medenica, Mirjana, Ivanović, D., Janković, Saša, Malenović, Anđelija, "Monitoring of fosinopril sodium impurities by liquid chromatography-mass spectrometry including the neural networks in method evaluation" in Journal of Chromatography A, 1189, no. 1-2 (2008):366-373,
https://doi.org/10.1016/j.chroma.2007.11.076 . .

TY  - JOUR
AU  - Popović, Igor
AU  - Ivanović, Darko
AU  - Medenica, Mirjana
AU  - Malenović, Anđelija
AU  - Jančić-Stojanović, Biljana
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1039
AB  - The main objective in all optimization procedures is to define the most appropriate conditions for rapid, sensitive, precise, and reproducible analysis, as economically as possible. Experimental design and DryLab optimization software have been used to optimize a liquid chromatographic method for separation of lercanidipine and its three impurities. In both methods of optimization the acetonitrile content and pH of the mobile phase were factors extracted for analysis; resolution of a critical pair was output in both cases. Data obtained from both optimization methods were compared and appropriate conclusions were extracted with the objective of gaining a complete view of chromatographic behavior. Detailed description was obtained by use of a three-dimensional graph and DryLab maps. Both methods of optimization reported the most appropriate mobile phase to be a 35:65 mixture of acetonitrile and an aqueous solution of 1.5% TEA, pH adjusted to 3.0 by addition of orthophosphoric acid, at a flow rate 1.0 mL min(-1). Separations were performed on a 20 x 4.6 mm, 3.5-mu m particle size, C-18 column, at 20 degrees C, with UV detection at 240 nm. The method was validated. All the results proved the reliability of the method, so it can be used for separation, identification, and simultaneous determination of these substances in the drug and in pharmaceutical dosage forms.
PB  - Vieweg, Wiesbaden
T2  - Chromatographia
T1  - LC determination of lercanidipine and its impurities using DryLab software and experimental design procedures
VL  - 67
IS  - 5-6
SP  - 449
EP  - 454
DO  - 10.1365/s10337-008-0536-3
ER  - 

@article{
author = "Popović, Igor and Ivanović, Darko and Medenica, Mirjana and Malenović, Anđelija and Jančić-Stojanović, Biljana",
year = "2008",
abstract = "The main objective in all optimization procedures is to define the most appropriate conditions for rapid, sensitive, precise, and reproducible analysis, as economically as possible. Experimental design and DryLab optimization software have been used to optimize a liquid chromatographic method for separation of lercanidipine and its three impurities. In both methods of optimization the acetonitrile content and pH of the mobile phase were factors extracted for analysis; resolution of a critical pair was output in both cases. Data obtained from both optimization methods were compared and appropriate conclusions were extracted with the objective of gaining a complete view of chromatographic behavior. Detailed description was obtained by use of a three-dimensional graph and DryLab maps. Both methods of optimization reported the most appropriate mobile phase to be a 35:65 mixture of acetonitrile and an aqueous solution of 1.5% TEA, pH adjusted to 3.0 by addition of orthophosphoric acid, at a flow rate 1.0 mL min(-1). Separations were performed on a 20 x 4.6 mm, 3.5-mu m particle size, C-18 column, at 20 degrees C, with UV detection at 240 nm. The method was validated. All the results proved the reliability of the method, so it can be used for separation, identification, and simultaneous determination of these substances in the drug and in pharmaceutical dosage forms.",
publisher = "Vieweg, Wiesbaden",
journal = "Chromatographia",
title = "LC determination of lercanidipine and its impurities using DryLab software and experimental design procedures",
volume = "67",
number = "5-6",
pages = "449-454",
doi = "10.1365/s10337-008-0536-3"
}

Popović, I., Ivanović, D., Medenica, M., Malenović, A.,& Jančić-Stojanović, B.. (2008). LC determination of lercanidipine and its impurities using DryLab software and experimental design procedures. in Chromatographia
Vieweg, Wiesbaden., 67(5-6), 449-454.
https://doi.org/10.1365/s10337-008-0536-3

Popović I, Ivanović D, Medenica M, Malenović A, Jančić-Stojanović B. LC determination of lercanidipine and its impurities using DryLab software and experimental design procedures. in Chromatographia. 2008;67(5-6):449-454.
doi:10.1365/s10337-008-0536-3 .

Popović, Igor, Ivanović, Darko, Medenica, Mirjana, Malenović, Anđelija, Jančić-Stojanović, Biljana, "LC determination of lercanidipine and its impurities using DryLab software and experimental design procedures" in Chromatographia, 67, no. 5-6 (2008):449-454,
https://doi.org/10.1365/s10337-008-0536-3 . .

TY  - JOUR
AU  - Malenović, Anđelija
AU  - Jančić-Stojanović, Biljana
AU  - Medenica, Mirjana
AU  - Ivanović, D.
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1058
AB  - This paper reports development and validation of a new microemulsion liquid chromatographic (MELC) method for rapid screening of simvastatin and simvastatin acid in human plasma. Plasma samples were injected directly into the HPLC system after appropriate sample dilution with mobile phase. Separations were performed on a 4.6 mm x 150 mm, 5-mu m particle, C-18 column, with UV detection at 238 nm. The mobile phase was 0.5% (w/v) diisopropyl ether, 1.0% (w/v) sodium dodecylsulphate (SDS), 4.0% (w/v) n-butanol, and 94.5% (w/w) aqueous 25 mM disodium hydrogen phosphate, pH 7.0, at a flow rate of 1 mL min(-1). The method was evaluated according to criteria stated in FDA bioanalytical method validation guidance. The unique approach applied in this paper enables direct analysis of simvastatin and simvastatin acid, so the method can be used to obtain reliable results in a rapid and simple way.
PB  - Akademiai Kiado Zrt, Budapest
T2  - Acta Chromatographica
T1  - Microemulsion Liquid Chromatographic Screening of Simvastatin and its Active Metabolite in Human Plasma
VL  - 20
IS  - 4
SP  - 595
EP  - 607
DO  - 10.1556/AChrom.20.2008.4.6
ER  - 

@article{
author = "Malenović, Anđelija and Jančić-Stojanović, Biljana and Medenica, Mirjana and Ivanović, D.",
year = "2008",
abstract = "This paper reports development and validation of a new microemulsion liquid chromatographic (MELC) method for rapid screening of simvastatin and simvastatin acid in human plasma. Plasma samples were injected directly into the HPLC system after appropriate sample dilution with mobile phase. Separations were performed on a 4.6 mm x 150 mm, 5-mu m particle, C-18 column, with UV detection at 238 nm. The mobile phase was 0.5% (w/v) diisopropyl ether, 1.0% (w/v) sodium dodecylsulphate (SDS), 4.0% (w/v) n-butanol, and 94.5% (w/w) aqueous 25 mM disodium hydrogen phosphate, pH 7.0, at a flow rate of 1 mL min(-1). The method was evaluated according to criteria stated in FDA bioanalytical method validation guidance. The unique approach applied in this paper enables direct analysis of simvastatin and simvastatin acid, so the method can be used to obtain reliable results in a rapid and simple way.",
publisher = "Akademiai Kiado Zrt, Budapest",
journal = "Acta Chromatographica",
title = "Microemulsion Liquid Chromatographic Screening of Simvastatin and its Active Metabolite in Human Plasma",
volume = "20",
number = "4",
pages = "595-607",
doi = "10.1556/AChrom.20.2008.4.6"
}

Malenović, A., Jančić-Stojanović, B., Medenica, M.,& Ivanović, D.. (2008). Microemulsion Liquid Chromatographic Screening of Simvastatin and its Active Metabolite in Human Plasma. in Acta Chromatographica
Akademiai Kiado Zrt, Budapest., 20(4), 595-607.
https://doi.org/10.1556/AChrom.20.2008.4.6

Malenović A, Jančić-Stojanović B, Medenica M, Ivanović D. Microemulsion Liquid Chromatographic Screening of Simvastatin and its Active Metabolite in Human Plasma. in Acta Chromatographica. 2008;20(4):595-607.
doi:10.1556/AChrom.20.2008.4.6 .

Malenović, Anđelija, Jančić-Stojanović, Biljana, Medenica, Mirjana, Ivanović, D., "Microemulsion Liquid Chromatographic Screening of Simvastatin and its Active Metabolite in Human Plasma" in Acta Chromatographica, 20, no. 4 (2008):595-607,
https://doi.org/10.1556/AChrom.20.2008.4.6 . .

TY  - JOUR
AU  - Jančić, Biljana
AU  - Medenica, Mirjana
AU  - Ivanović, Darko
AU  - Malenović, Anđelija
PY  - 2007
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/921
AB  - Pramipexole is a dopamine D2-agonist/antiparkinsonian agent in which BI-II 546 CL, BI-II 751 xx and 2-amino benzothiazole are commonly found as impurities. Due to the lack of analytical data on pramipexole and its related substances in bulk drug and pharmaceuticals, we aim at the optimization and characterisation of the chromatographic behaviour of pramipexole and its related substances employing experimental design. The analysis was performed using a C18 column with mobile phases containing different ratios of acetonitrile and water phase (aqueous triethylamine/ortophosporic acid). The detection was performed at 262 nm for pramipexole, BI-II 751 xx and 2-aminobenzthiazole and at 326 nm for BI-II 546 CL. To define the influence of chromatographic parameters on separation, a central composite design was chosen. The content of acetonitrile, TEA and pH of the water phase were identified as the factors with important influences on retention. Using an appropriate mathematical model, we were able to predict retention under different conditions.
PB  - Slovensko Kemijsko Drustvo, Ljubljana
T2  - Acta Chimica Slovenica
T1  - Experimental design in chromatographic analysis of pramipexole and its impurities
VL  - 54
IS  - 1
SP  - 49
EP  - 54
UR  - https://hdl.handle.net/21.15107/rcub_farfar_921
ER  - 

@article{
author = "Jančić, Biljana and Medenica, Mirjana and Ivanović, Darko and Malenović, Anđelija",
year = "2007",
abstract = "Pramipexole is a dopamine D2-agonist/antiparkinsonian agent in which BI-II 546 CL, BI-II 751 xx and 2-amino benzothiazole are commonly found as impurities. Due to the lack of analytical data on pramipexole and its related substances in bulk drug and pharmaceuticals, we aim at the optimization and characterisation of the chromatographic behaviour of pramipexole and its related substances employing experimental design. The analysis was performed using a C18 column with mobile phases containing different ratios of acetonitrile and water phase (aqueous triethylamine/ortophosporic acid). The detection was performed at 262 nm for pramipexole, BI-II 751 xx and 2-aminobenzthiazole and at 326 nm for BI-II 546 CL. To define the influence of chromatographic parameters on separation, a central composite design was chosen. The content of acetonitrile, TEA and pH of the water phase were identified as the factors with important influences on retention. Using an appropriate mathematical model, we were able to predict retention under different conditions.",
publisher = "Slovensko Kemijsko Drustvo, Ljubljana",
journal = "Acta Chimica Slovenica",
title = "Experimental design in chromatographic analysis of pramipexole and its impurities",
volume = "54",
number = "1",
pages = "49-54",
url = "https://hdl.handle.net/21.15107/rcub_farfar_921"
}

Jančić, B., Medenica, M., Ivanović, D.,& Malenović, A.. (2007). Experimental design in chromatographic analysis of pramipexole and its impurities. in Acta Chimica Slovenica
Slovensko Kemijsko Drustvo, Ljubljana., 54(1), 49-54.
https://hdl.handle.net/21.15107/rcub_farfar_921

Jančić B, Medenica M, Ivanović D, Malenović A. Experimental design in chromatographic analysis of pramipexole and its impurities. in Acta Chimica Slovenica. 2007;54(1):49-54.
https://hdl.handle.net/21.15107/rcub_farfar_921 .

Jančić, Biljana, Medenica, Mirjana, Ivanović, Darko, Malenović, Anđelija, "Experimental design in chromatographic analysis of pramipexole and its impurities" in Acta Chimica Slovenica, 54, no. 1 (2007):49-54,
https://hdl.handle.net/21.15107/rcub_farfar_921 .

TY  - JOUR
AU  - Medenica, Mirjana
AU  - Ivanović, D.
AU  - Magković, M.
AU  - Jančić, Biljana
AU  - Malenović, Anđelija
PY  - 2007
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/968
AB  - Perindopril tert-butylamine is a new member of angiotensin-converting enzyme inhibitors group used in the treatment of hypertension and heart failure. In this paper, the evaluation of reversed-phase high-performance liquid chromatographic method (RP-HPLC) for the determination of impurities level of perindopril tert-butylamine in tablets was done. The chromatograms were recorded using a Hewlett Packard 1100 chromatographic system with DAD detector. Separations were performed on a YMC-Pack C8 column (250 mm x 4.6 mm; 5 mu m particle size) at 50 degrees C column temperature. Mobile phase was a mixture of acetonitrile-potassium phosphate buffer (0.05 M) (37:63, v/v) (pH 2.5). pH of the mobile phase was adjusted with ortophosphoric acid. Mixture of acetonitrile-water (40:60, v/v) was used as a solvent. Injection volume was 50 mu l, flow rate 1.7 ml min(-1) and UV-detection was performed at 215 nm. The developed method subjected to method validation and parameters in terms of selectivity, linearity, precision, accuracy, limit of detection, limit of quantitation and robustness were defined. The validated method is suitable for the simultaneous determination of perindopril tert-butylamine as well as its impurities in pharmaceuticals.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Pharmaceutical and Biomedical Analysis
T1  - Evaluation of impurities level of perindopril tert-butylamine in tablets
VL  - 44
IS  - 5
SP  - 1087
EP  - 1094
DO  - 10.1016/j.jpba.2007.05.008
ER  - 

@article{
author = "Medenica, Mirjana and Ivanović, D. and Magković, M. and Jančić, Biljana and Malenović, Anđelija",
year = "2007",
abstract = "Perindopril tert-butylamine is a new member of angiotensin-converting enzyme inhibitors group used in the treatment of hypertension and heart failure. In this paper, the evaluation of reversed-phase high-performance liquid chromatographic method (RP-HPLC) for the determination of impurities level of perindopril tert-butylamine in tablets was done. The chromatograms were recorded using a Hewlett Packard 1100 chromatographic system with DAD detector. Separations were performed on a YMC-Pack C8 column (250 mm x 4.6 mm; 5 mu m particle size) at 50 degrees C column temperature. Mobile phase was a mixture of acetonitrile-potassium phosphate buffer (0.05 M) (37:63, v/v) (pH 2.5). pH of the mobile phase was adjusted with ortophosphoric acid. Mixture of acetonitrile-water (40:60, v/v) was used as a solvent. Injection volume was 50 mu l, flow rate 1.7 ml min(-1) and UV-detection was performed at 215 nm. The developed method subjected to method validation and parameters in terms of selectivity, linearity, precision, accuracy, limit of detection, limit of quantitation and robustness were defined. The validated method is suitable for the simultaneous determination of perindopril tert-butylamine as well as its impurities in pharmaceuticals.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Pharmaceutical and Biomedical Analysis",
title = "Evaluation of impurities level of perindopril tert-butylamine in tablets",
volume = "44",
number = "5",
pages = "1087-1094",
doi = "10.1016/j.jpba.2007.05.008"
}

Medenica, M., Ivanović, D., Magković, M., Jančić, B.,& Malenović, A.. (2007). Evaluation of impurities level of perindopril tert-butylamine in tablets. in Journal of Pharmaceutical and Biomedical Analysis
Elsevier Science BV, Amsterdam., 44(5), 1087-1094.
https://doi.org/10.1016/j.jpba.2007.05.008

Medenica M, Ivanović D, Magković M, Jančić B, Malenović A. Evaluation of impurities level of perindopril tert-butylamine in tablets. in Journal of Pharmaceutical and Biomedical Analysis. 2007;44(5):1087-1094.
doi:10.1016/j.jpba.2007.05.008 .

Medenica, Mirjana, Ivanović, D., Magković, M., Jančić, Biljana, Malenović, Anđelija, "Evaluation of impurities level of perindopril tert-butylamine in tablets" in Journal of Pharmaceutical and Biomedical Analysis, 44, no. 5 (2007):1087-1094,
https://doi.org/10.1016/j.jpba.2007.05.008 . .

TY  - JOUR
AU  - Ivanović, Darko
AU  - Malenović, Anđelija
AU  - Jančić, Biljana
AU  - Medenica, Mirjana
AU  - Masković, Marija
PY  - 2007
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/941
AB  - The multi-component preparation Co -Diovan (R) is indicated for the hypertension treatment in patients whose blood pressure is not adequately controlled by monotherapy. Its active ingredients are valsartan and hydrochlorothiazide. The reversed-phase high performance liquid chromatographic method (RP -HPLC) for the determination of valsartan and hydrochlorothiazide, as well as their impurities level, was developed and described in this paper. As the investigated substances were structurally different with extremely different lipophilicity and polarity, isocratic elution was not possible, so an optimal gradient mode was settled on. The chromatograms were recorded using the Agilent 1100 Series chromatographic system with DAD detector. Separations were performed on a Hypersil 120-5 ODS column (250 mm x 4.6 mm; 5 mm particle size) at 25 degrees C column temperature. The gradient high performance liquid chromatographic system was developed, and the following mobile phases were used: A) mixture acetonitrile -water (10: 90 V/V); pH of the mobile phase was adjusted to 2.5 with 85% orthophosphoric acid, and B) mixture acetonitrile -water (90: 10 V/V); pH of the mobile phase was adjusted to 2.5 with 85% orthophosphoric acid. Injection volume was 50 mu L, flow rate 1 mL min(-1) and UV detection was performed at 256 nm. Methyl parahydroxybenzoate was used as an internal standard and acetonitrile-water (40:60 V/V) as a solvent. Afterwards, the developed method was subjected to the method validation. The investigated validation parameters (selectivity, linearity, precision, accuracy, LOQ, and LOD) proved the suitability of the method for the simultaneous determination of valsartan, hydrochlorothiazide, and their impurities in appropriate tablets.
PB  - Taylor & Francis Inc, Philadelphia
T2  - Journal of Liquid Chromatography & Related Technologies
T1  - Monitoring of impurity level of valsartan and hydrochlorothiazide employing an RP-HPLC gradient mode
VL  - 30
IS  - 19
SP  - 2879
EP  - 2890
DO  - 10.1080/10826070701588638
ER  - 

@article{
author = "Ivanović, Darko and Malenović, Anđelija and Jančić, Biljana and Medenica, Mirjana and Masković, Marija",
year = "2007",
abstract = "The multi-component preparation Co -Diovan (R) is indicated for the hypertension treatment in patients whose blood pressure is not adequately controlled by monotherapy. Its active ingredients are valsartan and hydrochlorothiazide. The reversed-phase high performance liquid chromatographic method (RP -HPLC) for the determination of valsartan and hydrochlorothiazide, as well as their impurities level, was developed and described in this paper. As the investigated substances were structurally different with extremely different lipophilicity and polarity, isocratic elution was not possible, so an optimal gradient mode was settled on. The chromatograms were recorded using the Agilent 1100 Series chromatographic system with DAD detector. Separations were performed on a Hypersil 120-5 ODS column (250 mm x 4.6 mm; 5 mm particle size) at 25 degrees C column temperature. The gradient high performance liquid chromatographic system was developed, and the following mobile phases were used: A) mixture acetonitrile -water (10: 90 V/V); pH of the mobile phase was adjusted to 2.5 with 85% orthophosphoric acid, and B) mixture acetonitrile -water (90: 10 V/V); pH of the mobile phase was adjusted to 2.5 with 85% orthophosphoric acid. Injection volume was 50 mu L, flow rate 1 mL min(-1) and UV detection was performed at 256 nm. Methyl parahydroxybenzoate was used as an internal standard and acetonitrile-water (40:60 V/V) as a solvent. Afterwards, the developed method was subjected to the method validation. The investigated validation parameters (selectivity, linearity, precision, accuracy, LOQ, and LOD) proved the suitability of the method for the simultaneous determination of valsartan, hydrochlorothiazide, and their impurities in appropriate tablets.",
publisher = "Taylor & Francis Inc, Philadelphia",
journal = "Journal of Liquid Chromatography & Related Technologies",
title = "Monitoring of impurity level of valsartan and hydrochlorothiazide employing an RP-HPLC gradient mode",
volume = "30",
number = "19",
pages = "2879-2890",
doi = "10.1080/10826070701588638"
}

Ivanović, D., Malenović, A., Jančić, B., Medenica, M.,& Masković, M.. (2007). Monitoring of impurity level of valsartan and hydrochlorothiazide employing an RP-HPLC gradient mode. in Journal of Liquid Chromatography & Related Technologies
Taylor & Francis Inc, Philadelphia., 30(19), 2879-2890.
https://doi.org/10.1080/10826070701588638

Ivanović D, Malenović A, Jančić B, Medenica M, Masković M. Monitoring of impurity level of valsartan and hydrochlorothiazide employing an RP-HPLC gradient mode. in Journal of Liquid Chromatography & Related Technologies. 2007;30(19):2879-2890.
doi:10.1080/10826070701588638 .

Ivanović, Darko, Malenović, Anđelija, Jančić, Biljana, Medenica, Mirjana, Masković, Marija, "Monitoring of impurity level of valsartan and hydrochlorothiazide employing an RP-HPLC gradient mode" in Journal of Liquid Chromatography & Related Technologies, 30, no. 19 (2007):2879-2890,
https://doi.org/10.1080/10826070701588638 . .

TY  - JOUR
AU  - Jančić, Biljana
AU  - Medenica, Mirjana
AU  - Ivanović, D.
AU  - Malenović, Anđelija
PY  - 2007
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/920
AB  - The main goal in this investigation was monocratic HPLC determination of dissociation constant values (pK(a)) of pramipexole and its impurities, BI-II 546 CL, BI-II 751 xx and 2-aminobenzothiazole. The chromatographic method is advantageous as a small amount of substance is needed and the degree of substance purity is less important. Analysis was carried out using stationary phases stable in a wide pH range. Triethylamonium phosphoric buffer was selected as appropriate pH controlling solution because it can cover a wide pH range. Detection was done on two different wavelengths, 262 nm for pramipexole, BI-II 751 xx and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL. The constants were calculated from the typical sigmoidal curves of analyte obtained as retention factor versus the pH of the mobile phase.
PB  - Vieweg, Wiesbaden
T2  - Chromatographia
T1  - Chromatographic determination of dissociation constants of pramipexole and its impurities
VL  - 65
IS  - 9-10
SP  - 633
EP  - 635
DO  - 10.1365/s10337-007-0199-5
ER  - 

@article{
author = "Jančić, Biljana and Medenica, Mirjana and Ivanović, D. and Malenović, Anđelija",
year = "2007",
abstract = "The main goal in this investigation was monocratic HPLC determination of dissociation constant values (pK(a)) of pramipexole and its impurities, BI-II 546 CL, BI-II 751 xx and 2-aminobenzothiazole. The chromatographic method is advantageous as a small amount of substance is needed and the degree of substance purity is less important. Analysis was carried out using stationary phases stable in a wide pH range. Triethylamonium phosphoric buffer was selected as appropriate pH controlling solution because it can cover a wide pH range. Detection was done on two different wavelengths, 262 nm for pramipexole, BI-II 751 xx and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL. The constants were calculated from the typical sigmoidal curves of analyte obtained as retention factor versus the pH of the mobile phase.",
publisher = "Vieweg, Wiesbaden",
journal = "Chromatographia",
title = "Chromatographic determination of dissociation constants of pramipexole and its impurities",
volume = "65",
number = "9-10",
pages = "633-635",
doi = "10.1365/s10337-007-0199-5"
}

Jančić, B., Medenica, M., Ivanović, D.,& Malenović, A.. (2007). Chromatographic determination of dissociation constants of pramipexole and its impurities. in Chromatographia
Vieweg, Wiesbaden., 65(9-10), 633-635.
https://doi.org/10.1365/s10337-007-0199-5

Jančić B, Medenica M, Ivanović D, Malenović A. Chromatographic determination of dissociation constants of pramipexole and its impurities. in Chromatographia. 2007;65(9-10):633-635.
doi:10.1365/s10337-007-0199-5 .

Jančić, Biljana, Medenica, Mirjana, Ivanović, D., Malenović, Anđelija, "Chromatographic determination of dissociation constants of pramipexole and its impurities" in Chromatographia, 65, no. 9-10 (2007):633-635,
https://doi.org/10.1365/s10337-007-0199-5 . .