Chinese J. Trad. Pat. Med. (Zhongchengyao) 26 (9), App.14-16 (2004). TLC on silica gel with 1) toluene - ethyl acetate - formic acid 25:20:4; 2) ethyl acetate - methanol - water 100:17:13. Detection 1) by spraying with diazotized para-nitroaniline solution; 2) by spraying with 5 % AlCl3 in ethanol and under UV 365 nm. Identification by fingerprint technique. Quantification of hesperidin by HPLC.

Talanta 61 (5), 581-589 (2003). TLC of clopidogrel bisulphate on silica gel with carbon tetrachloride - chloroform - acetone 12:8:3. Rf value of clopidogrel bisulphate was 0.30. Clopidogrel bisulphate was subjected to acid and alkali hydrolysis, oxidation, photodegradation and dry heat treatment. The drug was susceptible to acid - base hydrolysis, oxidation and dry heat degradation. Also the degraded products were well separated from the pure drug with significantly different Rf values. Quantitative determination by absorbance measurement at 230 nm. The linear regression data for the calibration plots showed good linear relationship with r2=0.999 in the concentration range of 200-1000 ng. The mean value of correlation coefficient, slope and intercept were 0.999±0.001, 0.093±0.011 and 8.83±0.99, respectively. The method was validated for precision, accuracy, ruggedness and recovery. The limits of detection and quantitation were 40 and 120 ng per spot, respectively.

by thin-layer chromatography) (Chinese). J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (8), 941-944 (2005). TLC of betaine on silica gel with acetone - ethanol - hydrochloric acid 10:6:1. Detection by spraying with a solution of potassium iodobismuthate. Quantitative determination by densitometry at 515 nm. Validation regarding linearity range (8.0 - 39.0 µg, r = 0.9992), precision (RSD = 1.62 %, n = 6), reproducibility (RSD = 2.14 %, n = 6), and recovery (99.75 %, RSD = 1.92 %, n = 6). Results are given for 12 real life samples. Discussion of the advantages of the method compared to HPLC.

Pharmazie 61, 15-17 (2006). TLC of seven local anesthetics (benzocaine, procaine, tetracaine, lidocaine, prilocaine, bupivacaine, articaine) and the related antiarrhythmic drug procainamide on silica gel with ethyl acetate - methanol - 32 % ammonia 96:2:3 with chamber saturation for 15 min. Detection a) under UV light at 254 nm; b) spraying with cobalt(II) thiocyanate solution; c) by subsequent spraying with Ehrlich’s reagent. Except for articaine/prilocaine all drugs could be distinguished. However, articaine could be distinguished from prilocaine and other local anesthetics by a colour reaction with copper(II) sulfate solution.

59th Indian Pharmaceutical congress F-225, 443, (2007). HPTLC cinnamaldehyde in the bark powder of Cinnamomum zeylenicum on silica gel with toluene - ethyl acetate - formic acid 190:10:1. Densitometric evaluation at 295 nm for quantification. The method was linear within the range of 31 and 157 ng/zone. The identity of the compound was confirmed by over overlaying the UV spectra of sample and standard. Cinnamomum bark was found to contain 0.25 % of cinnamaldehyde. Limit of detection and quantification was 3000 and 9900 ng/mL, respectively.

Chromatographia 70 (1-2), 309-313 (2009). TLC on silica gel with acetonitrile - methanol - dichloromethane 2:1:2. The hRf value of dutasteride was 64. Separation of dutasteride from its degradation products (produced by acid and alkali hydrolysis, oxidation, photo degradation, dry and wet heat treatment) was good. Quantitative determination by absorbance measurement at 244 nm. Linearity was in the range of 100 - 600 ng/band and the correlation coefficient was 0.9943 (via peak area) The limit of detection and quantitation was 7 and 23 ng/band.

J. Chinese Trad. Patent Med. 30 (12), Supl. 4-6 (2008). TLC of the TCM drug extracts on silica gel with 1) dichloromethane - ethyl acetate - methanol - water 15:40:22:10; 2) petroleum ether (60-90 °C) - diethyl ether 3:2; 3) petroleum ether (60-90 °C) - ethyl acetate 25:2; 4) n-butanol - acetic acid - water 4:1:2; 5) chloroform - diethyl ether 1:1. Detection 1) by spraying with 10 % sulfuric acid in ethanol followed by heating at 105 °C until coloration; 2) under UV 365 nm; 3) under UV 254 nm.

Talanta, 80 (5), 2007-2015 (2010). Presentation of a method for determination of oxybutynin hydrochloride (OX) in presence of its degradation product and additives in its pharmaceutical formulations. UV spectrophotometry using the first derivative of ratio spectra and measurment at 216 nm. Chemometric analysis using principal component regression and partial least-squares. HPTLC of OX and its degradation products methylparaben and propylparaben on silica gel with chloroform - methanol - ammonia - triethylamine 500:15:2.5:1. Quantitative determination by densitometry at 220 nm. Comparison of the results obtained with all three methods showed no significant differences.