TY  - JOUR
AU  - Vovk, Irena
AU  - Popović, Gordana
AU  - Simonovska, Breda
AU  - Albreht, Alen
AU  - Agbaba, Danica
PY  - 2011
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1570
AB  - The separation of structurally related angiotensin-converting enzyme (ACE) inhibitors lisinopril, cilazapril, ramipril and quinapril and their corresponding active diacid forms (prilates) by conventional TLC silica gel 60 plates was contrasted with that afforded by monolithic ultra-thin-layer chromatographic (UTLC) plates. For the use of UTLC plates technical modifications of the commercially available equipments for the sample application, development and detection were made. Plates were developed in modified horizontal developing chamber using ethyl acetate-acetone-acetic acid-water (4:1:0.25:0.5, v/v). Detection of the separated compounds was performed densitometrically in absorption/reflectance mode at 220 nm and after exposure to iodine also by image analysis. The obtained results showed that monolithic layer is more efficient for the separation of structurally similar polar compounds, such as prilates than conventional silica layers. Identification of the compounds was confirmed by ESI-MS after their on-line extraction from the UTLC and TLC plates by means of Camag TLC-MS interface.
PB  - Elsevier Science BV, Amsterdam
T2  - Journal of Chromatography A
T1  - Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors
VL  - 1218
IS  - 20
SP  - 3089
EP  - 3094
DO  - 10.1016/j.chroma.2011.03.039
ER  - 

@article{
author = "Vovk, Irena and Popović, Gordana and Simonovska, Breda and Albreht, Alen and Agbaba, Danica",
year = "2011",
abstract = "The separation of structurally related angiotensin-converting enzyme (ACE) inhibitors lisinopril, cilazapril, ramipril and quinapril and their corresponding active diacid forms (prilates) by conventional TLC silica gel 60 plates was contrasted with that afforded by monolithic ultra-thin-layer chromatographic (UTLC) plates. For the use of UTLC plates technical modifications of the commercially available equipments for the sample application, development and detection were made. Plates were developed in modified horizontal developing chamber using ethyl acetate-acetone-acetic acid-water (4:1:0.25:0.5, v/v). Detection of the separated compounds was performed densitometrically in absorption/reflectance mode at 220 nm and after exposure to iodine also by image analysis. The obtained results showed that monolithic layer is more efficient for the separation of structurally similar polar compounds, such as prilates than conventional silica layers. Identification of the compounds was confirmed by ESI-MS after their on-line extraction from the UTLC and TLC plates by means of Camag TLC-MS interface.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "Journal of Chromatography A",
title = "Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors",
volume = "1218",
number = "20",
pages = "3089-3094",
doi = "10.1016/j.chroma.2011.03.039"
}

Vovk, I., Popović, G., Simonovska, B., Albreht, A.,& Agbaba, D.. (2011). Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors. in Journal of Chromatography A
Elsevier Science BV, Amsterdam., 1218(20), 3089-3094.
https://doi.org/10.1016/j.chroma.2011.03.039

Vovk I, Popović G, Simonovska B, Albreht A, Agbaba D. Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors. in Journal of Chromatography A. 2011;1218(20):3089-3094.
doi:10.1016/j.chroma.2011.03.039 .

Vovk, Irena, Popović, Gordana, Simonovska, Breda, Albreht, Alen, Agbaba, Danica, "Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors" in Journal of Chromatography A, 1218, no. 20 (2011):3089-3094,
https://doi.org/10.1016/j.chroma.2011.03.039 . .

TY  - CONF
AU  - Ravanić, Nina
AU  - Nikolić, Katarina
AU  - Popović, Gordana
AU  - Vovk, Irena
AU  - Simonovska, Breda
AU  - Filipić, Slavica
AU  - Agbaba, Danica
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/5205
AB  - Alfa lipoinska (tioktinska) kiselina se koristi u lečenju dijabetesne polineuropatije. Zbog svojih antioksidativnih svojstava, prisutna je u brojnim dijetetskim suplementima sama, kao i u kombinaciji sa aminokiselinama, L-karnitinom i drugim jedinjenjima. Dostupni podaci za kvantitativno određivanje alfa lipoinske kiseline su malobrojni. Usled toga, cilja našeg rada bio je da se razvije i validira TLC metoda za određivanje alfa lipoinske kiseline posle derivatizacije sa paladijum (II) hloridom. 
Za razdvajanje alfa lipoinske kiseline i njenog redukovanog oblika korišćene su RPTLC ploče veličine 20×10 cm, uz mobilnu fazu propanol-2 : methanol : aceton : voda : sirćetna kiselina u odnosu 6:4:2:8:0,2 v/v/v/v/v. Nakon razvijanja, hromatografske ploče su potapane u rastvor paladijum (II) hlorida, a žute zone formiranog kompleksa su merene na 375 nm. Retenciona vremena alfa lipoinske kiseline i njene redukovane forme su 45 i 32 nm. Zavisnost površine signala i količine nanete supstance ispitana je korišćenjem linearne regresione jednačine za opseg koncentracija 1 – 3 μg i polinomalne regresione jednačine drugog stepena za koncentracioni opseg 0,5 – 5 μg. Za datu metodu dobijene vrednosti koeficijenta korelacije (r=0,999), limit kvantifikacije (0,3 μg), rikaveri (98,5 – 105,2%) i preciznost (0,9 – 2,9%) su zadovoljavajući.
Validirana hromatografska metoda je primenjena za određivanje alfa lipoinske kiseline u doziranim oblicima i dijetetskim suplementima. Nađeni sadržaj lipoinske kiseline (98,5 – 102,0%) u doziranim oblicima je u propisanim granicama, dok je u dijetetskim suplementima varirao u rasponu od 50 – 185%.
AB  - Alpha lipoic (thioctic) acid is a drug used for the treatment of diabetic polyneuropathy. Due to its antioxidant properties alpha lipoic acid nowadays widely used in dietary supplement preparation alone and in combination with amino acids, L-carnitine and other compounds. There are not so many data available on the quantitative determination of alpha lipoic acid in dietary supplements. Therefore, the aim of these investigations was to develop and validated TLC method for determination of alpha lipoic acid after derivatization by Palladium (II) chloride reagent. 
The separation of alpha lipoic acid was performed on RPTLC plates (20 × 10 cm) using propanol-2 : methanol : acetone : water : acetic acid (6:4:2:8:0.2 v/v/v/v/v) as mobile phase. The plates were immersed in solutions of Palladium (II) chloride reagents and yellow spots were scanned at 375 nm. The retention times of alpha lipoic acid and its reduced form were 45 and 32 mm, respectively. Relationship of the peak areas and the amount of the substance applied was evaluated using the linear (1 -3 μg/spot) and second degree polynomial regression function (0.5 – 5 μg/spot). For the proposed procedure coefficient of correlation (r=0.999), limit of quantification (0.3 μg/spot), recovery (98.5 – 105.2 %) and precision (0.9 – 2.9%) were found to be satisfactory. 
The developed method was applied for determination of alpha lipoic acid in drugs dosage formulations and in dietary supplement preparation. The content of lipoic acid were found to be 98.5 – 102.0% in drug dosage formulations and 50 – 185.0% in some of dietary supplement preparations.
PB  - Udruženje za medicinu sporta Srbije
PB  - Institut za bromatologiju Farmaceutskog fakulteta u Beogradu
C3  - Drugi kongres o dijetetskim suplementima sa međunarodnim učešćem, Apstrakti
T1  - Determination of alpha lipoic acid in dietary supplement preparations and in drug formulations
T1  - Određivanje alfa lipoinske kiseline u dijetetskim suplementima i doziranim oblicima
SP  - 139
EP  - 140
UR  - https://hdl.handle.net/21.15107/rcub_farfar_5205
ER  - 

@conference{
author = "Ravanić, Nina and Nikolić, Katarina and Popović, Gordana and Vovk, Irena and Simonovska, Breda and Filipić, Slavica and Agbaba, Danica",
year = "2009",
abstract = "Alfa lipoinska (tioktinska) kiselina se koristi u lečenju dijabetesne polineuropatije. Zbog svojih antioksidativnih svojstava, prisutna je u brojnim dijetetskim suplementima sama, kao i u kombinaciji sa aminokiselinama, L-karnitinom i drugim jedinjenjima. Dostupni podaci za kvantitativno određivanje alfa lipoinske kiseline su malobrojni. Usled toga, cilja našeg rada bio je da se razvije i validira TLC metoda za određivanje alfa lipoinske kiseline posle derivatizacije sa paladijum (II) hloridom. 
Za razdvajanje alfa lipoinske kiseline i njenog redukovanog oblika korišćene su RPTLC ploče veličine 20×10 cm, uz mobilnu fazu propanol-2 : methanol : aceton : voda : sirćetna kiselina u odnosu 6:4:2:8:0,2 v/v/v/v/v. Nakon razvijanja, hromatografske ploče su potapane u rastvor paladijum (II) hlorida, a žute zone formiranog kompleksa su merene na 375 nm. Retenciona vremena alfa lipoinske kiseline i njene redukovane forme su 45 i 32 nm. Zavisnost površine signala i količine nanete supstance ispitana je korišćenjem linearne regresione jednačine za opseg koncentracija 1 – 3 μg i polinomalne regresione jednačine drugog stepena za koncentracioni opseg 0,5 – 5 μg. Za datu metodu dobijene vrednosti koeficijenta korelacije (r=0,999), limit kvantifikacije (0,3 μg), rikaveri (98,5 – 105,2%) i preciznost (0,9 – 2,9%) su zadovoljavajući.
Validirana hromatografska metoda je primenjena za određivanje alfa lipoinske kiseline u doziranim oblicima i dijetetskim suplementima. Nađeni sadržaj lipoinske kiseline (98,5 – 102,0%) u doziranim oblicima je u propisanim granicama, dok je u dijetetskim suplementima varirao u rasponu od 50 – 185%., Alpha lipoic (thioctic) acid is a drug used for the treatment of diabetic polyneuropathy. Due to its antioxidant properties alpha lipoic acid nowadays widely used in dietary supplement preparation alone and in combination with amino acids, L-carnitine and other compounds. There are not so many data available on the quantitative determination of alpha lipoic acid in dietary supplements. Therefore, the aim of these investigations was to develop and validated TLC method for determination of alpha lipoic acid after derivatization by Palladium (II) chloride reagent. 
The separation of alpha lipoic acid was performed on RPTLC plates (20 × 10 cm) using propanol-2 : methanol : acetone : water : acetic acid (6:4:2:8:0.2 v/v/v/v/v) as mobile phase. The plates were immersed in solutions of Palladium (II) chloride reagents and yellow spots were scanned at 375 nm. The retention times of alpha lipoic acid and its reduced form were 45 and 32 mm, respectively. Relationship of the peak areas and the amount of the substance applied was evaluated using the linear (1 -3 μg/spot) and second degree polynomial regression function (0.5 – 5 μg/spot). For the proposed procedure coefficient of correlation (r=0.999), limit of quantification (0.3 μg/spot), recovery (98.5 – 105.2 %) and precision (0.9 – 2.9%) were found to be satisfactory. 
The developed method was applied for determination of alpha lipoic acid in drugs dosage formulations and in dietary supplement preparation. The content of lipoic acid were found to be 98.5 – 102.0% in drug dosage formulations and 50 – 185.0% in some of dietary supplement preparations.",
publisher = "Udruženje za medicinu sporta Srbije, Institut za bromatologiju Farmaceutskog fakulteta u Beogradu",
journal = "Drugi kongres o dijetetskim suplementima sa međunarodnim učešćem, Apstrakti",
title = "Determination of alpha lipoic acid in dietary supplement preparations and in drug formulations, Određivanje alfa lipoinske kiseline u dijetetskim suplementima i doziranim oblicima",
pages = "139-140",
url = "https://hdl.handle.net/21.15107/rcub_farfar_5205"
}

Ravanić, N., Nikolić, K., Popović, G., Vovk, I., Simonovska, B., Filipić, S.,& Agbaba, D.. (2009). Determination of alpha lipoic acid in dietary supplement preparations and in drug formulations. in Drugi kongres o dijetetskim suplementima sa međunarodnim učešćem, Apstrakti
Udruženje za medicinu sporta Srbije., 139-140.
https://hdl.handle.net/21.15107/rcub_farfar_5205

Ravanić N, Nikolić K, Popović G, Vovk I, Simonovska B, Filipić S, Agbaba D. Determination of alpha lipoic acid in dietary supplement preparations and in drug formulations. in Drugi kongres o dijetetskim suplementima sa međunarodnim učešćem, Apstrakti. 2009;:139-140.
https://hdl.handle.net/21.15107/rcub_farfar_5205 .

Ravanić, Nina, Nikolić, Katarina, Popović, Gordana, Vovk, Irena, Simonovska, Breda, Filipić, Slavica, Agbaba, Danica, "Determination of alpha lipoic acid in dietary supplement preparations and in drug formulations" in Drugi kongres o dijetetskim suplementima sa međunarodnim učešćem, Apstrakti (2009):139-140,
https://hdl.handle.net/21.15107/rcub_farfar_5205 .

TY  - JOUR
AU  - Ravanić, N.
AU  - Filipić, Slavica
AU  - Nikolić, Katarina
AU  - Popović, Gordana
AU  - Vovk, Irena
AU  - Simonovska, Breda
AU  - Agbaba, Danica
PY  - 2009
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1170
AB  - A simple and reliable TLC method for analysis of -lipoic acid ( LA) with post-chromatographic derivatisation with palladium(II) chloride immersion reagent has been developed and evaluated. Separation of LA was performed on 20 cm x 10 cm RPTLC plates with 2-propanol-methanol-acetone-water-acetic acid 6: 4: 2: 8: 0.2 (v/v) as mobile phase. Yellow complexes formed in situ were scanned at 375 nm. The migration distance of LA was 43.0 mm. The relationship between peak area and amount of LA applied was evaluated by use of linear (1.0-3.0 mu g per band) and second-degree polynomial ( 0.5-5.0 mu g per band) regression functions. The correlation coefficient (r = 0.999), the limit of quantification (0.39 mu g per band), recovery (98.5-105.2%), and precision (1.8-2.9%) obtained by use of the procedure were satisfactory. The method was used for analysis of LA in several drug formulations and selected dietary supplement preparations. The LA content was 99.5-101.0% in the drug formulations, 98.8-99.5% in three of five dietary supplements tested, and 48.0-185.0% in two other dietary supplements.
PB  - Akademiai Kiado Zrt, Budapest
T2  - Acta Chromatographica
T1  - Analysis of alpha-Lipoic Acid in Drug Formulations and Dietary Supplement Preparations
VL  - 21
IS  - 3
SP  - 433
EP  - 441
DO  - 10.1556/AChrom.21.2009.3.7
ER  - 

@article{
author = "Ravanić, N. and Filipić, Slavica and Nikolić, Katarina and Popović, Gordana and Vovk, Irena and Simonovska, Breda and Agbaba, Danica",
year = "2009",
abstract = "A simple and reliable TLC method for analysis of -lipoic acid ( LA) with post-chromatographic derivatisation with palladium(II) chloride immersion reagent has been developed and evaluated. Separation of LA was performed on 20 cm x 10 cm RPTLC plates with 2-propanol-methanol-acetone-water-acetic acid 6: 4: 2: 8: 0.2 (v/v) as mobile phase. Yellow complexes formed in situ were scanned at 375 nm. The migration distance of LA was 43.0 mm. The relationship between peak area and amount of LA applied was evaluated by use of linear (1.0-3.0 mu g per band) and second-degree polynomial ( 0.5-5.0 mu g per band) regression functions. The correlation coefficient (r = 0.999), the limit of quantification (0.39 mu g per band), recovery (98.5-105.2%), and precision (1.8-2.9%) obtained by use of the procedure were satisfactory. The method was used for analysis of LA in several drug formulations and selected dietary supplement preparations. The LA content was 99.5-101.0% in the drug formulations, 98.8-99.5% in three of five dietary supplements tested, and 48.0-185.0% in two other dietary supplements.",
publisher = "Akademiai Kiado Zrt, Budapest",
journal = "Acta Chromatographica",
title = "Analysis of alpha-Lipoic Acid in Drug Formulations and Dietary Supplement Preparations",
volume = "21",
number = "3",
pages = "433-441",
doi = "10.1556/AChrom.21.2009.3.7"
}

Ravanić, N., Filipić, S., Nikolić, K., Popović, G., Vovk, I., Simonovska, B.,& Agbaba, D.. (2009). Analysis of alpha-Lipoic Acid in Drug Formulations and Dietary Supplement Preparations. in Acta Chromatographica
Akademiai Kiado Zrt, Budapest., 21(3), 433-441.
https://doi.org/10.1556/AChrom.21.2009.3.7

Ravanić N, Filipić S, Nikolić K, Popović G, Vovk I, Simonovska B, Agbaba D. Analysis of alpha-Lipoic Acid in Drug Formulations and Dietary Supplement Preparations. in Acta Chromatographica. 2009;21(3):433-441.
doi:10.1556/AChrom.21.2009.3.7 .

Ravanić, N., Filipić, Slavica, Nikolić, Katarina, Popović, Gordana, Vovk, Irena, Simonovska, Breda, Agbaba, Danica, "Analysis of alpha-Lipoic Acid in Drug Formulations and Dietary Supplement Preparations" in Acta Chromatographica, 21, no. 3 (2009):433-441,
https://doi.org/10.1556/AChrom.21.2009.3.7 . .

TY  - JOUR
AU  - Miseljić, Branislava
AU  - Popović, Gordana
AU  - Agbaba, Danica
AU  - Marković, Slavko
AU  - Simonovska, Breda
AU  - Vovk, Irena
PY  - 2008
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/1077
AB  - A gradient reversed-phase column high-performance liquid chromatographic method was developed for the detection and quantification of norfloxacin and its major impurities in norfloxacin-containing pharmaceuticals. Chromatographic separations were performed under the following experimental conditions: column, Zorbax SB RP-18 (5 mu m, 250 x 4.6 mm); injection volume, 20 mu L; mobile phase, 0.05 M NaH2PO4 (pH 2.5)-acetonitrile (87 + 13) for 16 min and (58 + 42) for 9 min (stepwise gradient); and flow rate, 1.3 mL/min. All analyses were performed at 25 degrees C, and the eluate was monitored at 275 nm using a diode array detector. Linearity (correlation coefficient = 0.999), recovery (99.3-101.8%), relative standard deviation (0.2-0.7%), and quantitation limit (0.12-0.47 mu g/mL) were evaluated and found to be satisfactory. The method is simple, rapid, and convenient for purity control of norfloxacin in both raw materials and dosage forms.
PB  - AOAC Int, Gaithersburg
T2  - Journal of AOAC International
T1  - Column high-performance liquid chromatographic determination of norfloxacin and its main impurities in pharmaceuticals
VL  - 91
IS  - 2
SP  - 332
EP  - 338
UR  - https://hdl.handle.net/21.15107/rcub_farfar_1077
ER  - 

@article{
author = "Miseljić, Branislava and Popović, Gordana and Agbaba, Danica and Marković, Slavko and Simonovska, Breda and Vovk, Irena",
year = "2008",
abstract = "A gradient reversed-phase column high-performance liquid chromatographic method was developed for the detection and quantification of norfloxacin and its major impurities in norfloxacin-containing pharmaceuticals. Chromatographic separations were performed under the following experimental conditions: column, Zorbax SB RP-18 (5 mu m, 250 x 4.6 mm); injection volume, 20 mu L; mobile phase, 0.05 M NaH2PO4 (pH 2.5)-acetonitrile (87 + 13) for 16 min and (58 + 42) for 9 min (stepwise gradient); and flow rate, 1.3 mL/min. All analyses were performed at 25 degrees C, and the eluate was monitored at 275 nm using a diode array detector. Linearity (correlation coefficient = 0.999), recovery (99.3-101.8%), relative standard deviation (0.2-0.7%), and quantitation limit (0.12-0.47 mu g/mL) were evaluated and found to be satisfactory. The method is simple, rapid, and convenient for purity control of norfloxacin in both raw materials and dosage forms.",
publisher = "AOAC Int, Gaithersburg",
journal = "Journal of AOAC International",
title = "Column high-performance liquid chromatographic determination of norfloxacin and its main impurities in pharmaceuticals",
volume = "91",
number = "2",
pages = "332-338",
url = "https://hdl.handle.net/21.15107/rcub_farfar_1077"
}

Miseljić, B., Popović, G., Agbaba, D., Marković, S., Simonovska, B.,& Vovk, I.. (2008). Column high-performance liquid chromatographic determination of norfloxacin and its main impurities in pharmaceuticals. in Journal of AOAC International
AOAC Int, Gaithersburg., 91(2), 332-338.
https://hdl.handle.net/21.15107/rcub_farfar_1077

Miseljić B, Popović G, Agbaba D, Marković S, Simonovska B, Vovk I. Column high-performance liquid chromatographic determination of norfloxacin and its main impurities in pharmaceuticals. in Journal of AOAC International. 2008;91(2):332-338.
https://hdl.handle.net/21.15107/rcub_farfar_1077 .

Miseljić, Branislava, Popović, Gordana, Agbaba, Danica, Marković, Slavko, Simonovska, Breda, Vovk, Irena, "Column high-performance liquid chromatographic determination of norfloxacin and its main impurities in pharmaceuticals" in Journal of AOAC International, 91, no. 2 (2008):332-338,
https://hdl.handle.net/21.15107/rcub_farfar_1077 .