Chinese J. of Lishizhen Trad. Med. & Pharm. 22 (3), 677-680 (2011). Chinese Goldthread is a traditional Chinese medicinal herbal drug, the dry rhizome of Coptis chinensis Franch, Coptis dehoidea C.Y. Cheng et Hsiao and Coptis teeta Wal. is widely used as key component in preparations effective for clearing heat, eliminating dampness, purging intense heat and relieve internal heat or fever. Presentation of a TLC method for simultaneous determination of five varieties of alkaloids in Chinese Goldthread rhizome and identification of the characteristic component of Evodia rutaecarpa (Juss.) in the preparation Yuhuanglian. TLC of the extracts of Chinese Goldthread rhizome on silica gel with cyclohexane - ethyl acetate – isopropanol – methanol – water – triethylamine 6:7:2:3:1:2 after saturation for 20 min, detection under UV 366 nm, identification of jatrorrhizine hydrochloride, palmatine hydrochloride, berberine hydrochloride, epiberberine hydrochloride, and coptisine hydrochloride by comparison with the standards. TLC of the extracts of Yuhuanglian on silica gel with petroleum ether (60-90 ºC) – chloroform – acetone – methanol – diethylamine 25:10:10:5:1, detection by spraying with 2 % vanillin in ethanol - sulfuric acid 200:1 and heating at 105 °C until the zones were visible, identification of evodine by comparison with the standard.

J. Chromatogr. A 1260, 232-238 (2012). Presentation of a new RP-HPTLC method for the separation of pyrazinamide, isoniazid, rifampicin and ethambutol in a four fixed-dose combination tablet formulation by detection of pyrazinamide, isoniazid and rifampicin at UV 280 nm firstly, and then derivatization and detection of ethambutol at 450 nm after RP-plate development. Evaluation of methanol, ethanol and propan-1-ol as the modifiers to form alcohol-water mobile phases. Systematic optimization of the composition of each alcohol in the mobile phase by using the window diagramming concept to obtain the best separation. Examination of the Rf distribution of the separated compounds indicated that separation of the compounds with the mobile phase containing ethanol at the optimal fraction situated within the optimal hRf-values region of 20-80, thus ethanol was selected as the organic modifier and the optimal mobile phase composition was found to be ethanol – water - glacial acetic acid - 37 % ammonia 70:30:5:1.

Chinese J. Mod. Drug Appl. 6 (9), 124-125 (2012). Danbaijing capsules are a herbal TCM for treating intractable proteinuria. For quality control, TLC on silica gel 1) for Radix Astragali and the standard astragaloside A, with chloroform – methanol – water 13:7:2, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, viewing in daylight; 2) for Centella asiatica and the standard asiaticoside, with chloroform – methanol – water 14:6:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, viewing in daylight.

J. Strait Pharm. 24 (9), 53-55 (2012). Huoxiang Qushu Soft capsules are an approved herbal TCM preparation used for promoting perspiration, reducing internal heat, regulating spleen and stomach. For quality control, TLC on silica gel 1) for Herba Pogostemonis, with petroleum ether (30-60 ºC) – ethyl acetate – glacial acetic acid 85:15:1, detection by spraying with 5 % ferric chloride in ethanol and heating at 105 °C, viewing in daylight; 2) for Radix Angelicae Dahuricae, with petroleum ether (30-60 ºC) – diethyl ether 3:2, detection under UV 366 nm; 3) for Folium Perillae, with ethyl acetate – methanol – formic acid – water 18:1:2:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, viewing under UV 366 nm; 4) for Rhizoma Atractylodis, with petroleum ether (30-60 ºC) – acetone 9:2, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, viewing in daylight; 5) for Rhizoma Pinelliae Preparatum, with petroleum ether (30-60 ºC) – ethyl acetate – acetone – formic acid 60:12:10:1, detection under UV 254 nm; 6) for Poria, with toluene – ethyl acetate – formic acid 40:10:1, detection by spraying with 2 % vanillin in sulfuric acid – ethanol 1:200 and heating at 105 °C, viewing in daylight; 7) for Radix Glycyrrhizae, with ethyl acetate – formic acid – glacial acetic acid – water 15:1:1:2, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, viewing under UV 366 nm.

Trends in Chromatography 8, 1-6 (2013). HPTLC of neutral lipids and a neutral lipid standard (consisting of 20 % each of cholesterol, oleic acid, triolein, methyl oleate, and cholesteryl oleate) on silica gel (HLF plates with 19 scored channels of 9 mm width) prewashed with dichloromethane - methanol 1:1 and heated for 30 min at 120 °C, with petroleum ether - diethyl ether - glacial acetic acid 80:20:1 with chamber saturation. Detection by spraying with 5 % ethanolic phosphomolybdic acid reagent and heating at 120 °C for 5 min. Neutral lipids appeared as blue zones on a yellow background. The fractions of free sterols, free fatty acids, triacylglycerols, methyl esters, and steryl esters were identified by comparison with the standard mixture. Quantification by absorption measurement at 610 nm via linear calibration (peak area).

J. Planar Chromatogr. 26, 43-55 (2013). TLC of cefditoren pivoxil on silica gel with 1-butanol - acetic acid - water 17:2:1. Quantitative determination by absorbance measurement at 295 nm. The hRf of cefditoren pivoxil was 70. Linearity was in the range of 600-1600 ng/zone. The LOD and LOQ were 40 and 130 ng/zone, respectively. Recovery (by standard addition) was between 97.8 and 101.8 %. Intermediate/interday/intra-day precision was below 2 % (n=3). The method showed comparable results with a validated HPLC method.

Chinese J. of Northern Pharmacy 10 (6), 8-10 (2013). Radix Bupleuri is the dried root of Bupleurum chinense Dc. and Bupleurum scorzonerifolium Willd. (Umbelliferae). The crude drug has antipyretic, antiviral, anti-inflammatory and anti-tumor effects, and reduces blood lipid levels. The quality of the drug differs depending on its origin and harvesting time. For quality control, TLC on silica gel 1) with ethyl acetate – ethanol – water 8:2:1; and 2) with the lower phase of chloroform – ethyl acetate – methanol – water 15:40:22:10 after laying up at 10 °C. Detection by spraying with 2 % p-dimethylaminobenzaldehyhyde in 40 % sulfuric acid and heating at 60 °C until the zones are visible in daylight and under UV 366 nm. Identification by comparison with the standard Radix Stellaviae. Quantification of total Radix Stellaviae by UV spectrophotometry with p-dimethylaminobenzaldehyhyde – phosphoric acid colorization method at 545 nm. Quantification of Radix Stellaviae A and D by HPLC.

J. Liq. Chromatogr. Relat. Technol. 37, 367-378 (2014). TLC of curcumin (1), piperine (2), and boswellic acid (3) in polyherbal transdermal patch on silica gel aluminum foils with chlorofom - ethyl acetate - formic acid 75:60:2. Quantitative determination by absorbance measurement at 540 nm. The hRf values for (1) to (3) were 48, 52 and 61, respectively. The linear calibration range was selected at very high amounts (1-15 µg/zone for (1) to (3)) despite the low LOD and LOQ of 0.06 and 0.2 ng/zone for (1), 0.31 and 0.95 ng/zone for (2) and 14.22 and 43.10 ng/zone for (3). Average recovery (by standard addition) was in the range of 98-99 % for (1) to (3). Intermediate intra- and inter-day precision was below 0.1 % (n=6).