Indian Drugs 42 (10), 650-653 (2005). A simple rapid, precise and cost-effective HPTLC method has been developed for the determination of ursolic acid in Oscimum sanctum (Tulsi) leaves and its formulations (Tulsi ghan tablets and Tulsi capsules). HPTLC on silica gel with toluene - ethyl acetate - acetic acid 30:3:1. Detection with anisaldehyde in sulphuric acid reagent followed by heating in an oven at 110 °C. Quantitative determination by absorbance measurement at 580 nm. Linearity of the detector response was given in the range of 40 - 280 ng. LOD was 8 ng. The correlation coefficient obtained from linearity was 0.9985. The standard error was 26.511. The mean assay values of ursolic acid wa found to be 3.485 mg/g, 0.553 mg/g and 3.221 mg/g in tulsi ghan tablets, tulsi capsule and tulsi leaves respectively.

Abstract GP-75, IPC (2005). HPTLC of satranidazole and its degradation products on silica gel with toluene - acetonitrile 3:2. For stability studies, the sample was treated with NaOH, HCl, H2O2 and photolysis. Degradation products were well resolved with significant different Rf values. The method had a linearity range of 100-500 ng. The proposed method suitable to investigate the kinetics of hydrolysis and photodegradation processes with first order in NaOH, and zero order for photolysis.

Indian Drugs 42 (9), 600-603 (2005). HPTLC of cinnarizine and domperidone in tablets, on silica gel with toluene - ethyl acetate - methanol 14:1:5. Quantitative determination by absorbance measurement at 271 nm. Rf values of cinnarizine was 0.85 and of domperidone 0.4. Linearity was observed in the range of 0.1-0.4 for cinnarizine and 0.075-0.3 µg/µL for domperidone. The recoveries were in the range of 98.95-100.25 %. The tablet matrix did not interfere with the assay.

Application of SFC in implementation of uniform design for herbal drug standardization, with thermodynamic study. Acta Chrom. 17, 125-150 (2006). HPTLC of bacoside A3 and bacopaside II on RP-18 F254 after pre-washing with methanol and heating at 60° C for 5 min. Development with toluene – methanol – ethyl acetate 15:5:4 in the dark in a controlled humidity chamber (humidity of 55 - 65 %). Densitometry at 344 nm. The method is available for content determination of bacoside A3 and bacopaside II in herbal extracts and commercial formulations.

J. Planar Chromatogr. 19, 398-400 (2006). HPTLC of curcumin, piperine, and thymol on silica gel, pre-washed with methanol, without chamber saturation with toluene - ethyl acetate - methanol 18:2:1. Quantitative determination by absorbance measurement at 420 nm for curcumin, 333 nm for piperine, and 277 nm for thymol. Limit of detection for curcumin was 25 ng, for piperine 5 ng, and for thymol 50 ng. Rapid identification of the three compounds is also possible by spraying the plate with anisaldehyde in sulfuric acid reagent.

J. Planar Chromatogr. 19, 427-431 (2006). HPTLC of sildenafil citrate on silica gel, pre-washed with methanol, with toluene - acetone - methanol 3:1:1 in a saturated twin-trough chamber. Quantitative determination by absorbance measurement at 312 nm. The method was validated in accordance with ICH guidelines on the validation of analytical methods.

J. Liq. Chromatogr. & Relat. Technol. 29, 2787-2794 (2006). HPTLC of acids (from octanoic to octadecanoic) on RP-18 with methanol - water 9:1 and ethanol - water 19:1. Detection with iodine vapor. The characterisation by high values of determination coefficients suggest the possibility of using them to calculate and predict the values of solubilities in water of acids investigated.

Indian J. Pharm. Sci. 68 (6), 793-796 (2006). HPTLC of atorvastatin calcium and ezetimibe in combined dosage form on silica gel with chloroform - benzene - methanol - acetic acid 60:30:10:1. Detection under UV 250 nm.The method was validated in terms of linearity, accuracy, precision and specificity.The calibration curve was found to be linear between 0.8 and 4.0 µg/spot for atorvastatin calcium and 0.1 and 1.0 µg/spot for ezetimibe. The limit of detection and the limit of quantification for atorvastation calcium were found to be 170 ng/spot and 570 ng/spot, respectively, and for ezetimibe 20 ng/spot and 70 ng/spot, respectively.The recovery was in the range of 99.9 - 102.7 %.