J. Planar Chromatogr. 21, 209-212 (2008). HPTLC of levofloxacon, (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid, and amlodipine besylate (as internal standard) on silica gel, prewashed with methanol, with chloroform - methanol - acetic acid 58:39:3 in a twin trough chamber. Quantitation by densitometry at 300 nm (levofloxacin) and 350 nm (internal standard).

J. Planar Chromatogr. 21, 173-176 (2008). HPTLC of candesartan cilexetil and hydrochlorothiazide on silica gel with acetone - chloroform - ethyl acetate - methanol 6:6:6:1 at 25 +/- 5°C and a relative humidity of 50-60 % in a saturated twin trough separation chamber. Quantitation by densitometry at 280 nm.

J. Planar Chromatogr. 21, 21-26 (2008). HPTLC of extracts of Hoodia gordonii with fructose and beta-sitosterol as standards on silica gel with chloroform - methanol - water 70:30:3 in an automatic developing chamber fitted with a twin-trough chamber. The chamber was saturated for 20 min with mobile phase and relative humidity was controlled (33 %). Detection by dipping in anisaldehyde reagent, followed by heating at 100 °C for 3 min. Documentation and evaluation before derivatization under UV 366 nm and after derivatization under white light. The method was validated. It is specific and allows discrimination of Hoodia gordonii from Hoodia currorii, Hoodia parviflora, and the common adulterant prickly pear cactus (Opuntia ficus-indica). The sample is stable in solution and on the plate for at least 3 h, as well as during chromatography (2D test). After derivatization the chromatogram is stable for at least 1 hour. Precision (repeatability, intermediate precision, and reproducibility was good and the method is robust . The method is sensitive to changes in relative humidity. If relative humidity exceeds 47% the plate must be conditioned to 33% RH to ensure proper separation.

60th Indian Pharmaceutical Congress PA-206, (2008). HPTLC of (-)hydroxy citric acid in fruits of Garcina Gummigutta on silica gel with n-propanol - water - acetic acid 50:50:1 in a twin-trough chamber saturated for 10 min. Quantitative determination by absorbance measurement at 210 nm. The method was linear in the range of 100-1000 ng/spot. Recovery was 99.8-100.9 %.

Asian J. Chem. 20(4), 2531-2538 (2008). TLC of melatonin on silica gel with toluene - ethyl acetate - formic acid 10:9:1. Quantitative determination by absorbance measurement at 290 nm. The method was linear in the concentration range of 100 to 600 ng/spot. The recovery of the drug from tablets (by standard addition method) was 99.7 %. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of the drug. Forced degradation studies showed the effect of variations in pH, UV light and high temperature on the stability of melatonin. As the proposed method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.

J. Pharm. Res. 6(4), 205-207 (2007). HPTLC of itraconazole on silica gel with toluene - acetone - triethylamine 30:30:1. Quantitative determination by absorbance measurement at 270 nm. The hRf value of itraconazole was 62. Linearity was between 200 and 600 ng. The percent drug estimated from the market formulation was found to be 99.6 and 100.2 by peak height and peak area respectively. The percent recovery of the drug (by standard addition method) was between 99.4 and 100.3.

Chromatographia 69 (1-2), 157-161 (2009). TLC of amlodipine besylate (AML) and valsartan (VAL) on silica gel with toluene - methanol - acetic acid 70:30:1. Quantification by absorbance measurement at 244 nm. Linearity was between 100 - 600 ng/spot for AML and 1600 - 9600 ng/spot for VAL. For AML the RSD of intra-day precision was 1.5 - 1.8 % and of inter-day precision 1.2 - 2.0 %. For VAL the RSD of intra-day precision was 0.1 - 0.4 % and of inter-day precision 0.2 - 0.5 %. Accuracy was 98.3 % for AML and 98.7 % for VAL.

Asian J. Chem. 19(7), 5634-5638 (2007). TLC of rabeprazole sodium and itopride hydrochloride on silica gel prewashed with methanol, with toluene - chloroform - methanol - 25 % ammonia 5:6:2. Quantitative determination by absorbance measurement at 225 nm. Linearity was between 120 and 280 µg/mL for rabeprazole sodium and 900 and 1900 µg/mL for itopride hydrochloride. The recovery (by standard addition method) was between 98.1 and 99.5 % for both drugs. The proposed method is precise and accurate and can be used for routine analysis of rabeprazole sodium and itopride hydrochloride in capsule formulation.