J. Chinese Trad. Patent Med. (Zhongchengyao) 26 (1), 26-29 (2004). TLC on silica gel with 1) ethyl acetate - methanol - conc. ammonia 17:2:1, 2) cyclohexane - ethyl acetate - formic acid 30:15:1, or 50:10:1. Detection 1) by spraying with 5 % potassium iodobismuthate solution, 2) by spraying with 5 % vanillin in H2SO4 solution and heating at 105 ºC, 3) under UV 254 nm. Identification by fingerprint techniques. Quantitative determination of puerarin by HPLC.

CBS 93, 5-7 (2004). HPTLC of N,N-diethylethane-1,2-diamine in metoclopramide finished products on silica gel with 32 % ammonia - methanol - dichloromethane 3:15:80 over 40 mm with chamber saturation. Detection by dipping in 0.2 % ethanolic ninhydrin solution for 1 s, followed by drying at 120 °C for 5 min. Quantitative determination by absorbance measurement at 480 nm and evaluation of peak area with polynomial regression. The correlation coefficient of the calibration curve is 0.9995, the residual standard deviation 2.19 %. Intermediate precision is 1.65 %. Recovery for 0.2-1.0 % impurity is 100.5 %. Limit of quantitation is 0.05 % impurity.

Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (2), 110-113 (2004). TLC of Jixiangcao buccal tablet extracts on silica gel with 1) petroleum ether (30-60 ºC) - ethyl acetate 8:1 and 2) toluene - acetone - ethanol - ammonia 20:20:3:1. Detection 1) under UV 365 nm; 2) by spraying with 5 % potassium iodobismuthate solution and sodium nitrite solution. Identification by fingerprint technique. Quantification of ephedrine hydrochloride by HPLC.

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.

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 %).

IPC 56th 2004, Abstract No. GP-5. Simultaneous HPTLC determination of amlodipine and atenolol on silica gel with ethyl acetate - methanol - ammonia 60:40:3. Quantitative determination by scanning at 254 nm. The method was found linear in the range of 0.5 – 5.0 mg/mL amlodipine and 5.0 mg – 50 mg/mL atenolol. Recovery was 98.11 – 101.5 % for both of the compounds. The method was validated for accuracy, precision, linearity, specificity, LOD, and LOQ.

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 %.

Chinese J. Trad. Pat. Med. (Zhongchengyao) 26 (9), App.12-14 (2004). TLC on silica gel with 1) n-butanol - glacial - water 19:5:5; 2) chloroform - methanol - glacial acetic acid - 17:2:1; 3) two fold development with benzene - acetone 9:1. Detection 1) by spraying with ninhydrin solution and heating at 105 ºC; 2) by spraying with 5 % vanillin solution and heating; 3) by spraying with a solution of 8 % vanillin in ethanol - H2SO4, and heating at 105 ºC. Identification by fingerprint technique. Quantification of phyllyrin by densitometry at 280 nm. The quantitative procedure is validated by investigating its linearity (1 - 5 µg/spot, r = 0.9998); precision (RSD = 0.36 % n = 5); repeatability (RSD = 2.92 % n = 5) and standard addition recovery (99.6 %, RSD = 2.4 %, n = 5), etc. The determination results are given for a group of real life samples.