Chinese J. Hosp. Pharm. (Zhongguo Yiyuan Yaoxue Zazhi) 24 (2), 86-87 (2004). TLC on silica gel with toluene - 70% ethanol - methanol 35:35:10:6. Detection under UV light. Identification by standard comparison. Quantification by densitometry at 310 nm.

J. Chinese Trad. Patent Med. (Zhongchengyao) 26 (1), 23-26 (2004). TLC on silica gel with 1) chloroform - methanol - water 28:10:1, 2) n-hexane - ethyl acetate 9:1, 3) chloroform - methanol 5:1, 4) petroleum ether - diethyl ether 1:1. Detection 1) under UV 365 nm, 2) by spraying with 5 % vanillin in H2SO4 solution. Identification by fingerprint techniques. Quantitative determination of puerarin by HPLC.

Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (8), Appendix 22-24 (2004). Study of the quality standard of Naoxinkang pills by TLC in order to optimize the manufacture technology and clinical application. TLC of Naoxinkang pill extracts on silica gel with 1) the lower phase of chloroform - methanol - water 13:7:2; 2) chloroform - methanol - water 28:8:1; 3) cyclohexane - ethyl acetate 9:1. Detection 1) by spraying with 10 % H2SO4 in ethanol followed by heating at 105 ºC; 2) under UV 365 nm. Identification by fingerprint technique. Discussion of employing the procedures in the optimization of the manufacture technology and its clinical application for the medicine.

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).

Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (4), Appendix 8-9 (2004). TLC of Buzhongyiqi pill extracts on silica gel with ethyl acetate - formic acid - glacial acetic acid 15:1:1. Detection by spraying with 10 % H2SO4 in ethanol, followed by heating at 105 ºC. Evaluation under UV 365 nm. Identification by fingerprint techniques.

56th IPC 2004, Abstract No. GP-46. Stability indicating HPTLC determination of cefuroxime axetil in bulk drug and in formulations on silica gel with chloroform - methanol 23:2. Quantitative determination by scanning at 278 nm. The sample was subjected to acidic, and alkali hydrolysis, oxidation and photo degradation. The degraded products were well separated. The method was validated for accuracy, precision, linearity, specificity, ruggedness, and recovery (98 - 100 %).

IPC 56th 2004, Abstract No. DP-33. An HPTLC method is reported for the standardization of Trikatukuc Curanam, an Ayurvedic preparation with Piper nigrum and Piper longum, both containing piperine as major alkaloid. HPTLC of piperine on silica gel with toluene - ethyl acetate 7:3 .Extraction with methylene chloride, the evaporated residue of the organic layer was taken in ethyl acetate and subjected to the analysis.The band corresponding to piperine was scanned at 338 nm. Linearity was 8-40 ng with recovery of 99.03 %.

IPC 56th 2004, Abstract No. GP-26. HPTLC of triphala, an ayurvedic formulation containing about 3.60 % of total phenolics. Separation of alcoholic triphala extracts on silica gel with n-hexane - ethyl acetate 2:1. Rf value of the main spot gallic acid was 0.04 in triphala and its formulation. The method was found to be very specific for gallic acid having a linearity range of 0.2 - 1.6 mg/mL. Several formulations analyzed by HPTLC contained 5.2 - 7.6 % of gallic acid. The reported method is suitable for estimation of gallic acid in raw material and formulations.