J. Chromatogr. A 1216 (42), 7102-7107 (2009). HPTLC of co-trimoxazole tablets (combination of sulfamethoxazole and trimethoprim) on silica gel with toluene – ethyl acetate – methanol 100:57:43. Detection under UV 254 nm. The hRf values were 30 and 61 for trimethoprime and sulfamethoxazole, respectively. Quantification by densitometry at UV 254 nm. Cochran's criterion test indicated homoscedasticity of variances for the calibration data. The F-tests for lack-of-fit indicated that straight lines were adequate to describe the relationship between spot areas and concentrations for each compound. Repeatability and precision (%RSD) was 1.0 and 0.8 % for sulfamethoxazole as well as 1.3 % and 1.6 % for trimethoprim, respectively. Recovery was 99.0 % and 99.7 % for sulfamethoxazole and trimethoprim, respectively.

60th Indian Pharmaceutical Congress PA-226 (2008). HPTLC of olmesartan medoxomil (an angiotensin-II antagonist) on silica gel with toluene - acetonitrile - methanol - ethyl acetate - acetic acid (mobile phase ratio not specified by the authors). The hRf value was 56. Quantitative determination by absorbance measurement at 262 nm. The linearity was between 300-800 ng/spot. The method was suitable for separation of olmesartan medoxomil from degradation products obtained by forced stress conditions (acid, alkali, peroxide, light, heat).

Abstract No. F-277, 61st IPC (2009). HPTLC of theobromine in different extracts of tea (Camelia sinensis) on silica gel with ethyl acetate - methanol 27:3. Quantitative determination by absorbance measurement at 274 nm. The maximum content of theobromine in tea samples was 2.3 %. Linearity was in the range of 3-15 µg/zone. The limit of detection and quantification was 30 and 140 ng/spot, respectively.

Abstract No. F-259, 61st IPC (2009). HPTLC of ranolazine on silica gel with methanol - toluene 9:11 in a twin trough chamber with chamber saturation for 30 min. The hRf value was 64. Quantitative determination by absorbance measurement at 271 nm. The method was linear in the range of 2-14 µg/band. Recovery was 98.3-101.4 %.

Abstract No. F-320, 62st IPC (2009). HPTLC of ezetimibe on silica gel with ethyl acetate - toluene - methanol - formic acid 10:10:1:1. Quantitative determination by absorbance measurement at 231 nm. The method was linear in the range of 301-3610 ng/band. Recovery was 99.3-100.4 % The drug was exposed to different stress conditions (acid, base, oxidative, thermal) and all degradation products were well resolved from the main compound.

J. Planar Chromatogr. 22, 265-271 (2009). HPTLC of atorvastatin calcium, ramipril, and aspirin and extracts of pharmaceutical formulations on silica gel, prewashed with methanol, with methanol - benzene - ethyl acetate - glacial acetic acid 9:140:100:1 in a twin trough chamber, saturated with mobile phase for 30 min at room temperature. Quantitative determination by absorbance measurement at 210 nm. The limit of detection was 5 ng/zone for atorvastatin calcium, 3 ng/zone for ramipril, and 19 ng/zone for aspirin.

Abstract No. F-254, 61st IPC (2009). HPTLC of bupropion HCl on silica gel with quinine sulphate - methanol - water 13:20:12 in the first direction. Quinine sulphate was used as a chiral selector at a concentration of 3.5 mM. The two separated bands were detected under UV 366 nm. The hRf values of I (-) and d (+) isomers of bupropion HCl were 90 and 84, respectively. After the second run in the second dimension with methanol - water 80:13 they were better resolved with hRf values of 88 and 76.

60th Indian Pharmaceutical Congress PA-227 (2008). HPTLC of oxcarbazepine (in acetonitrile extracts of human plasma) on silica gel with ethyl acetate - toluene - methanol 7:2:1. The hRf values of oxcarbazepine and the internal standard chlorzoxazone were 54 and 86, respectively. The linearity range was 10-300 ng/mL, recovery from plasma was 75.2 %.