Abstract No. F-253, 61st IPC (2009). HPTLC of tenofovir and emtricitabine on silica gel with toluene - methanol - ethyl acetate - acetic acid 40:20:50:1. Quantitative determination by absorbance measurement at 273 nm. The hRf value was 52 for tenofovir and 40 for emtricitabine. Linearity of tenofovir and emtricitabine was in the range of 120-600 ng/spot and 80-560 ng/spot, respectively. The recovery was 99.9 and 99.5 % for tenofovir and emtricitabine, respectively.

Chinese J. Pharm. Anal. 28 (9), 1554-1556 (2008). TLC of scalreol on silica gel with n-hexane – ethyl acetate – formic acid 32:16:1. Detection by spraying with vanillin – sulfuric acid – ethanol 1:1:18. Quantification by densitometry at 520 nm. Linearity was between 10 and 50 µg/zone with a determination coefficient of 0.9994. Recovery was 100.1 % (n = 6, %RSD = 0.9). Repeatability (%RSD, n = 6) was 2.1 % within plate and 2.3 % plate-to-plate.

Indian Drugs 46(1), 78-81 (2009). HPTLC of atenolol and losartan potassium in tablets on silica gel with toluene - methanol - triethylamine 12:8:1 with chamber saturation for 45 min. Quantitative determination by absorbance measurement at 230 nm. The hRf value of atenolol was 45 and of losartan potassium 67. The method was linear in the range of 1000-4000 ng/spot for both compounds. The recovery was 98.8-98.9 %.

Abstract No. 9933, IHCB (2009). HPTLC of colchicines in Gloriosa superba (collected from different parts of India) on silica gel with ethyl acetate - methanol 200:27. The hRf value of colchicine was 29. Quantitative determination by absorbance measurement at 350 nm. The method was linear in the range of 50-1000 ng/spot. The sample collected from Kerala was found to contain highest level of colchicines (0.24 %).

J. Pharm. Biomed. Anal. 47, 841-846 (2008). HPTLC of iridoid glycosides in the aerial part of Gambhari (Gmelina arborea) with iridoid gycoside 6-0-(2”, 3”- dibenzoyl)-o-L-rhamnopyranosylcatalpol as a chemical marker for the standardization of G. arborea plant extracts on silica gel with chloroform - methanol 4:1. Quantitative determination by absorbance measurement at 240 nm and at 430 nm after derivatization with vanillin - sulfuric acid reagent. The linear working range was between 1000-5000 ng/spot with a good correlation coefficient of 0.994.

Abstract No. C-372, 61st IPC (2009). HPTLC of withanolide A in extracts and spansules dosage form on silica gel with toluene - ethyl acetate - formic acid 8:6:1. Densitometric evaluation at 254 nm. Withanolide A was well separated with an hRf value of 14. The linearity range was 40-200 ng/band.

J. Planar Chromatogr. 23, 123-128 (2010). HPTLC of rifabutin and isoniazid on silica gel with dichloromethane - acetone - methanol 20:7:2 in a twin-trough chamber previously saturated for 25 min. Quantitative determination by absorbance measurement at 504 nm for rifabutin (hRf 84) and at 262 nm for isoniazid (hRf 48). The linearity range was 10-70 and 5-35 µg/mL, the correlation coefficient was 0.9991 and 0.9989, the precision (RSD, n = 6) 0.90 % and 0.71 %, and precision on different days (RSD, n = 3) was 0.89 % and 1.01 %. LOD was 180 µg and 90 µg/zone, LOQ was 540 and 270 µg/zone, and the system suitability (RSD, n = 6) was 1.41 % and 1.86 % for rifabutin and isoniazid, respectively.

Abstract No. C-37, 61st IPC (2009). HPTLC of methanolic leaf extracts of Aloe vera (after purification with petroleum ether (60-80 °C)) on silica gel with toluene - ethyl acetate - glacial acetic acid - methanol 4:18:1:4. Under UV 254 nm six bands with hRf values of 12, 26, 34, 44, 62, and 84 were observed. These bands correspond to well known constituents of Aloe vera: aloeresin hRf 25, barbaloin hRf 33, aloe emodin hRf 43, emodin hRf 63. The bands with hRf values of 12 and 84 could not be identified. The reported finger print profiling can serve as potential technique for authentification and batch to batch consistency of herbal drugs.