Indian J. Pharm. Sci. 66 (3), 306-308 (2004). HPTLC on silica gel with n-butanol - methanol - 6 M ammonia 5:1:2. Gatifloxacin showed Rf values of 0.47 ± 0.03. Quantitative determination by absorbance measurement at 292 nm. The method was validated in terms of linearity (400-1200 ng/spot), precision (intra-day variation 1.3 to 3.2 %, inter-day variation 3.9 to 5.0 %), accuracy (93.3 to 99.4 %), and specificity. The limit of detection and limit of quantification for gatifloxacin were found to be 10 ng/spot and 50 ng/spot respectively. The method is simple, sensitive, precise, and can be used for the routine quality control testing of marketed tablet formulations (400 mg).

J. Planar Chromatogr. 17, 123-127 (2004). TLC of 5 fibrate-type drugs (bezafibrate, ciprofibrate, clofibrate, clofibric acid, fenofibrate, and gemfibrozil) on RP 18-, RP 8- and cyano-phase in horizontal chambers with chamber saturation with a phosphate buffer and different amounts of six modifiers, i.e. acetone, acetonitrile, dioxane, isopropanol, methanol, and tetrahydrofuran. The best separation of all drugs investigated was obtained with dioxane - pH 7.60 phosphate buffer 7:3. Visualization under UV light at 254 nm. Quantitative determination at 227 nm.

J. Planar Chromatogr. 17, 169-172 (2004). HPTLC of omeprazole and pantoprazole and their impurities omeprazole sulfone and N-methylpantoprazole on silica gel with chloroform - 2-propanol - 25 % ammonia - acetonitrile (108:12:3:40). Detection under UV light at 254 nm. Quantitation of omeprazole and omeprazole sulfone at 300 nm and of pantoprazole and N-methylpantoprazole at 295 nm in reflectance-absorbance mode. Regression coefficients (r > 0.998), recovery (90.7 - 120.0 %), and detection limits (0.025 - 0.05 %) were validated and found to be satisfactory.

IPC 56th 2004, Abstract No. GP-11. Stability indicating HPTLC determination of indapamide in tablets on silica gel with toluene - methanol 7:3. Quantitative determination by scanning at 246 nm. Optimization of experimental parameter such as band size, chamber saturation, and slit width. The method was linear in the range of 1.4 - 3.72 g, recovery was 100.01 %. The drug was subjected to stress conditions according to ICH guidelines, degradation products were separated from the pure drug. The method was validated for accuracy, precision, linearity, and specificity.

J. Planar Chromatogr. 18, 61-66 (2005). TLC of three antidiabetic agents (pioglitazone, rosiglitazone, and repaglinide) on silica gel RP-8 with buffer - organic modifier binary mobile phases of widely different compositon in horizontal chambers; visualization under UV light at 254 nm. Peak-purity tests by recording the in-situ spectra in the wavelength range of 200 to 400 nm.

J. Planar Chromatogr. 18, 308-313 (2005). HPTLC of beta-adrenergic-blocking agents (acebutolol, atenolol, betaxolol, bisoprolol, labetalol, metoprolol, oyprenolol, pindolol, propanolol, sotalol, timolol) on silica gel with chloroform - methanol - ammonia 75:35:1. Quantitative determination by absorbance measurement at 270 nm for atenolol, at 240 nm for acebutolol, at 289 nm for propanolol, and at 220 nm for bisoprolol. The limits of detection and determination ranged from 30 to 400 ng and recovery was from 97.1 to 102.2 %.

J. Planar Chromatogr. 18, 380-383 (2005). HPTLC of ethamsylate in tablets on silica gel (pre-washed with methanol) at 25 +/-2 °C with chloroform - methanol -acetic acid 10:5:1 in a pre-saturated twin-trough chamber. Quantitative determination by absorbance measurement at 300 nm. The validated calibration range was 500-2500 ng per spot (r = 0.997).

J. Pharm. Biomed. Anal 36, 617-620 (2004) HPTLC of caffeine in herbal products and energy drinks, on silica gel with ethyl acetate - methanol 17:3. Solid samples (capsules) were extracted with methanol, filtered and applied whereas liquid samples (coca cola) were applied after the effervescence has ceased. Quantitative determination by absorbance measurement at 275 nm. The developed method was validated for specificity, repeatability (CV < 5 %), recovery (98.90) and accurary (99.84). The levels of caffeine were 4.76-13.29 % and 0.011-0.032 % for the herbal products and the energy drinks resp.