Indian Drugs 41 (6), 354-357 (2004). HPTLC on silica gel with toluene - methanol - acetone - 10 % ammonia 80:40:20:1. Quantitative determination by absorbance measurement at 254 nm. The Rf value of pioglitazone hydrochloride was found to lie between 0.49-0.55. The linear dynamic response was found to be 2.0-4.0 µg/spot for pioglitazone hydrochloride. The results of the analysis have been validated statistically and by recovery studies. A simple, fast, specific and precise HPTLC method has been developed for the estimation of pioglitazone hydrochloride in its tablet dosage form.

Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (3), 248-249 (2004). TLC of astragaloside on silica gel with the lower phase of chloroform - methanol - water 13:6:2. Detection by spraying with 10 % H2SO4 in ethanol and heating at 105 ºC. Identification by comparison with the standard. Quantification by densitometry at 530 nm. Validation of the method by investigation of precision (RSD=2.2 % n=5 within plate and 3.0 % n=5 plate-to-plate), linearity range (0.45-2.28 µg/spot r=0.998), repeatability, reproducibility, and recovery (98.1 %, n=5, RSD=3.4 %).

J. Planar Chromatogr. 17, 328-334 (2004). HPTLC of eighteen pesticides (propaquizafob, quizalofop-P, triadimefon, triadimenol, dimethomorf, quinoxyfen, cyromazine, oxyfluorfen, fluoroglycofen, acetochlor, metazachlor, imazapyr, furalaxyl, triclopyr, buprofezin, pyriproxyfen, fenoxycarb, piperonyl butoxide) on cyano phase. The greatest spread of separated compounds was obtained by combining nonaqueous normal-phase mobile phases (tetrahydrofuran or ethyl acetate in n-heptane 1:4 in the first direction and aqueous reversed phases mobile phases (methanol - water 7:3 or acetonitrile - water 1:1) in the second dimension. Detection under UV light at 254 or 366 nm. Videoscanning and densitometry at 254 nm.

J. Planar Chromatogr. 17, 383-387 (2004). TLC of fenbufen, ibuprofen, ketoprofen, diclofenac sodium, mefenamic acid, and tiaprofenic acid on silica gel by ascending and horizontal techniques, and on RP-18 in horizontal chambers. Good separation was achieved on silica gel by horizontal development with chloroform - methanol - 25 % ammonia 67:25:8; reversed phase chromatography on RP-18 with 0.15 mol/L phosphate buffer, pH 5.73 - 10 % CTMA-Br (N-cetyl-N,N,N-trimethylammonium bromide) in methanol 7:13 enabled better separation of the six drugs. Detection under UV light at 254 nm - for ibuprofen detection was best achieved after normal phase chromatography with 20 % aqueous sodium carbonate solution. A simple videodensitometric procedure was developed and validated. RSD for quantitation of fenbufen was 2.44 - 3.10 %.

56th IPC 2004, Abstract No. GP-47. Stability indicating HPTLC determination of oxcarbazepine in tablet dosage form on silica gel with toluene - methanol 4:1. The Rf value of oxcarbazepine was 0.17. Quantitative determination by scanning at 255 nm. The compound was subjected to acid and alkali hydrolysis, oxidation, dry heat, and photo degradation. All degraded products were well resolved from the pure drug. The method was validated for accuracy, precision, linearity, robustness, and recovery.

CBS 95, 10-13 (2005). HPTLC of five sulfonamides on silica gel with dichloroethane - methanol - 2-propanol - ammonia 25:5:5:1 in the twin trough chamber and ADC 2 with varied chamber saturation. Densitometric evaluation by absorbance measurement at 254 nm. Comparison of chamber saturation in conventional twin trough chamber and Automatic Development Chamber ADC 2 respectively. Reproducibility of Rf-values is better in ADC 2 due to higher quality in chamber saturation and less manual operations.

J. Planar Chromatogr. 18, 400-402 (2005). HPTLC of beta-carotene on silica gel and RP-18 with preadsorbent sample-application zones (prewashed with dichloromethane - methanol 1:1) with petroleum ether (35-60 °C) - acetonitrile - methanol 1:2:2 or petroleum ether (20-40°C) - acetone 7:3. HPTLC of biliverdin on silica gel with n-butanol - methanol - water 4:2:3. Quantitative determination by absorbance measurement at 628 nm.

J. AOAC Int. 88, 1544-1548 (2005). TLC of antimycotics (bifonazole, clotrimazole, and miconazole) and preservatives (benzyl alcohol, benzoic acid) on silica gel with 1) ethyl acetate - n-heptane - methanol - diethylamine 30:45:10:2 for bifonazole and benzyl alcohol; 2) n-butyl acetate - n-heptane - methanol - diethylamine 30:45:10:2 for clotrimazole and benzyl alcohol; 3) n-butyl acetate - carbon tetrachloride - methanol - diethylamine 6:12:5:1 for miconazole and benzoic acid. Quantitative determination by reflectance/absorbance measurement at 230 nm (bifonazole, benzyl alcohol, miconazole, and benzoic caid) and at 210 nm (clotrimazole and benzyl alcohol). Recovery rates for all substances ranged from 98.7 to 100.7 %. The limits of detection and quantitation were 0.03 to 0.2 µg and 0.1 to 0.5 µg/spot, respectively.