Indian Drugs 41 (8), 482-487 (2004). HPTLC on silica gel with toluene - acetone - ammonia 50:50:1. Quantitative determination by absorbance measurement at 315 nm. The method was validated in terms of linearity (300-1000 ng/spot), precision, accuracy, and specificity. For the content uniformity test the tizanidine hydrochloride content of 10 individual tablet units of two market formulations was determined after extracting with methanol. Both formulations compiled with the USP specification. The proposed content uniformity allows the parallel analysis of ten tablets on a single plate and provides a faster and cost-effective quality control tool for routine analysis. A simple, sensitive HPTLC content uniformity test was developed and validated for the analysis of tizanidine hydrochloride in its commercial single component tablet formulations (2 mg/tablet).

J. Planar Chromatogr. 17, 255-260 (2004). TLC of fourteen 1-arylpiperazine derivatives on silica gel with monocomponent and binary non-polar mobile phases and on RP-18 with binary mobile phases comprising mixtures of methanol, acetone, or dioxane (as organic modifiers) and water in a horizontal chamber after equilibration for 15 min. Detection under UV light at 254 nm.

56th IPC 2004, Abstract No. GP-48. HPTLC of rabeprazole sodium in tablet dosage form on silica gel with ethyl acetate - methanol 9:1. Optimization of experimental parameters such as bandwidth, chamber saturation time, solvent front migration, and mobile phase composition. Quantitative determination by scanning at 260 nm. The Rf value was 0.59. The method was linear with a correlation coefficient of 0.99, recovery was 98.81 %.

Abstract G-35, IPC (2005). HPTLC of etoricoxib in tablets on silica gel with n-hexane - ethyl acetate 1:3. Quantitative determination by absorbance measurement at 237 nm. The method was linear within the range of 100-500 ng/spot with a recovery rate of 97.4 %. LOD was 40 ng/spot and LOQ 100 ng/spot.

J. AOAC Int. 88, 1525-1529 (2005). HPTLC of trandolapril and verapamil in 2-component mixtures and in their combination capsules on silica gel in horizontal chambers with ethyl acetate - ethanol - acetic acid 16:4:1. Quantitative determination by densitometric measurement at 215 nm. Detection and quantitation limits were found to be 1.25 and 3.75 µg/spot for TRA and 0.15 and 0.45 µg/spot for VER, respectively.

Abstract CP-31, IPC (2005). HPTLC of stigmasterol in leptadernia reticulata on silica gel with n-hexane - ethyl acetate 4:1. Quantitative determination by absorbance measurement at 525 nm after derivatization. Both hydrolyzed and unhydrolyzed samples (2N HCl) were analysed. Unhydrolyzed samples were found to contain a higher amount of stigmasterol. Linearity was in the range of 0.16-0.48 mg/mL. Several market samples were analysed by the proposed method.

J. Planar Chromatogr. 19, 228-232 (2006). HPTLC of pantoprazole sodium sesquihydrate (5-difluoromethoxy-2-[(3,4-dimethoxy-2-pyridinyl)methyl]sulfinyl-1H-benzimidazole) on silica gel after prewashing with methanol in a twin-trough chamber presaturated for 10 min with methanol - water - ammonium acetate 8:2:1. Quantitation by densitometric scanning at 290 nm. The method was validated for linearity, sensitivity, precision, accuracy, specificity, system suitability, ruggedness and robustness, and repeatability.

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.