J. Liq. Chrom. & Rel. Technol. 25, 2821-2831 (2002). HPTLC of tenoxicam [4-hydroxy-2-methyl-N-2-(pyridyl)-2H-thieno[2,3-e]1,2-thiazin-3-carboxamid-1,1-dioxide] and photodegradation products on silica gel, prewashed with methanol - dichloromethane 1:1. The mobile phase consisted of dichloromethane - ethyl acetate - 96% acetic acid 16:4:1. Densitometry at 280 nm.

J. Planar Chromatogr. 15, 345-348 (2002). HPTLC of enoxacin, ofloxacin, and pefloxacin on silica gel in unsaturated horizontal chambers with dichloromethane - methanol - NH3 14:10:3. Detection and quantitation by videodensitometry at 254 nm and by classical densitometry at the wavelength of maximum absorption of the drugs determined. Calibration plots in the range 0.1 to 0.6 µg/µl were linear for all analytes with good correlation coefficients (r from 0.992 to 0.998), the precision, expressed as RSD, was between 7.56 and 10.08. The mean recoveries of the tree antibiotics from tablets ranged from 97.46 to 102.87%.

J. Liq. Chrom. & Rel. Technol. 26, 2719-2727 (2003). HPTLC of famotidine on silica gel (with concentrating zone) with ethyl acetate - methanol - toluene - NH3 conc. 40:25:20:2 with 15 min chamber saturation. Quantitation by densitometry at 254 nm. Evaluation of precision (1.25 - 2.55% RSD) and accuracy.

J. Liq. Chrom. & Rel. Technol. 26, 2709-2717 (2003). HPTLC of betamethasone on silica gel with chloroform - methanol - water 36:10:1. Quantitation by densitometry at 245 nm. The method was tested for linearity, homogeneity, detection limit, accuracy, and working range. Mean recovery 99.2-100.1%. Selective, precise, and accurate procedure.

J. Pharm. Biomed. Anal. 36, 23-31 (2004). An HPTLC method is reported for stress degradation studies of guggulsterone in gum-resin exudates of comniphora mukul. The degradation was carried out under different ICH prescribed stress conditions, followed by development of a stability indicating HPTLC method. Separation on silica gel with toluene - acetone 9:1 after pre-washing with methanol. Quantitative determination by absorbance measurement at 250 nm. Guggulsterone E and Z showed Rf values of 0.38 and 0.46 respectively. The proposed method allows separation of the drug from its degradation products and hence is suitable for stability studies.

Br. using gymnestrogenin as reference. Indian J. Pharm. Sci. 66 (2), 242-244 (2004). HPTLC of gymnestrogenin in Gymnema sylvestre on silica gel with chloroform - methanol 9:1. Quantitative determination by absorbance measurement at 293 nm. Linearity was in the range of 4-10 µg. A gymnestrogenin content of 1.11 % was found in the test sample. Average percentage recovery was 99.1 ±0.27. The proposed method is precise and sensitive and can be used for detection, monitoring, and quantification of gymnestrogenin in Gymnema sylvestre.

56th IPC 2004, Abstract No. GP-46. Stability indicating HPTLC determination of cefuroxime axetil in bulk drug and in formulations on silica gel with chloroform - methanol 23:2. Quantitative determination by scanning at 278 nm. The sample was subjected to acidic, and alkali hydrolysis, oxidation and photo degradation. The degraded products were well separated. The method was validated for accuracy, precision, linearity, specificity, ruggedness, and recovery (98 - 100 %).

IPC 56th 2004, Abstract No. G-18. Curculigo Orchioides (Amary llidaceae) is used in various ayurvedic formulations. The rhizomes contain about 5.78 % total phenolis, gallic acid being the major component of the alcoholic extracts. HPTLC of gallic acid on silica gel with toluene - ethyl acetate - glacial acetic acid 25:15:1. The Rf valueof gallic acid was 0.19, the linearity range of 150-750 ng/spot. Rhizomes were found to contain 2.54 % gallic acid, formulations contained 5.13 % gallic acid, recovery was 99.5 %.