J. of China Pharm. 20 (9), 16-17 (2011). TLC of the extracts of Biyan syrup 1) for Herba Ephedrae, on silica gel with chloroform - methanol - ammonia 40:10:1, detection by spraying with ninhydrin reagent and heating at 105 ºC; 2) for Flos Magnoliae, on silica gel with chloroform - diethyl ether 5:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC; 3) for Radix Astragali, on silica gel with ethyl acetate - butanone - formic acid - water 5:3:1:1, detection by spraying with 5 % iron(III) chloride in ethanol; 4) for Angelica dahurica (Fisch.) Benth. et Hook, on silica gel with toluene - petroleum ether (60-90 ºC) - ethyl acetate 6:3:1, detection under UV 366 nm.

Chinese J. of Pharm. Anal. 29 (9), 1458-1461 (2009). TLC of Ershiwuwei Luronghao pill extracts on silica gel with toluene - ethyl acetate - water - formic acid 20:10:1:1. Detection under UV 365 nm. Identification of aristolochic acid A by comparison of the hRf value with the standard. The method was rapid and precise and suitable for the quality control of the medicine.

International Journal of PharmTech Research 3(2), 1174-1178 (2011). TLC of lamotrigine on silica gel with ethyl acetate - chloroform - water 18:6:5. The hRf value was 40. Quantitative determination at 240 nm. The linearity was in the range of 98-590 ng/band with an average recovery of 100.2 %. LOD and LOQ were 44 and 122 ng/zone.

J. Planar Chromatogr. 24, 48-52 (2011). HPTLC of hydroquinone on silica gel with chloroform - methanol 17:3 in a twin-trough chamber after saturation for 30 min at 25 °C. Quantitative determination by densitometry in absorbance mode at 289 nm. The hRf of hydroquinone was 51. Linearity was between 100 and 2500 ng/zone. Mean recovery was 99.2 %, with %RSD between 1.7-2.0 %. The intra-day precision (n = 3) as %RSD was 0.9-1.1 % and the inter-day precision 1.0-1.2 %. The LOD and LOQ was 39 and 116 ng/band, respectively.

J. Planar Chromatogr. 24, 44-47 (2011). HPTLC of nitrazepam on silica gel with benzene - ethanol 5:1 in a horizontal chamber with saturation for 50 min. Quantitative determination by densitometry in absorbance mode at 196 nm. The hRf of nitrazepam was 68. Linearity was in the range of 0.25-10.0 µg/zone. Mean recovery was 98.8 % and 98.8 % for tablet and pure powder, respectively. Precision and accuracy (%RSD) were 1.3 % and 1.2 %, respectively. LOD and LOQ were 0.49 and 1.52 µg/mL, respectively.

J. Planar Chromatogr. 24, 242-247 (2011). HPTLC of E-guggulsterone (EG), Z-guggulsterone (ZG), 11-keto-ß-boswellic acid (11-KBA), and 3-acetyl-11-keto-ß-boswellic acid (A-11-KBA) in pharmaceutical formulation on silica gel with n-hexane - chloroform - ethyl acetate - methanol 10:3:3:1 in a twin-trough chamber with saturation for 15 min at room temperature (25 +/- 2 °C) and relative humidity of 60 +/- 5 %. Quantitative determination by densitometry in absorbance mode at 254 nm. The hRf values were 28, 39, 61, 68 for 11-KBA, A-11-KBA, EG, and ZG, respectively. The linearity range was 10-90 ng/band for EG and ZG, and 50-450 ng/band for 11-KBA and A-11-KBA. The repeatability of measurement of peak area and of sample application (%RSD) were 1.1 and 1.3 % for EG, 1.4 and 1.5 % for ZG, 0.5 and 1.1 % for 11-KBA, and 1.1 and 1.1 % for A-11-KBA, respectively. The mean intra-day and inter-day precsions (%RSD) were 1.0 and 1.1 % for EG, 1.1 and 0.9 % for ZG, 0.7 and 0.8 % for 11-KBA, and 1.1 and 1.3 for A-11-KBA. The method precisions (%RSD) were 1.3, 1.3, 1.1, and 1.3 % and the recoveries (by standard addition) were 96.9, 97.4, 97.6 and 97.2 % for EG, ZG, 11-KBA and A-11-KBA, respectively.

Volumes 1-3, CBS Publishers & Distributors, New Delhi, India (2013). The first volume provides a comprehensive introduction to the HPTLC technique, including details for each HPTLC step as well as various factors which influence the performance of a HPTLC analysis. Then presented over 3 volumes, 528 protocols for the HPTLC analysis of pharmaceutical formulations follow. Each protocol provides details on the preparation of samples and standards, chromatographic equipment, parameters for densitometric evaluation, chromatographic conditions, including stationary phase, mobile phase, standard and sample application, chamber saturation, relative humidity, quantity of mobile phase, temperature, migration distance and other critical parameters. References to the original publication are given as well as comments on the validation or any comparative study. Each protocol is illustrated with a typical densitogram, structures of the compounds analysed and overlaid UV spectra of compounds analysed (for selection of suitable wavelength for densitrometric scanning). All in all a comprehensive collection of protocols for pharmaceutical formulations.

J. Liq. Chromatogr. Relat. Technol. 35, 2548-2564 (2012). HPTLC of tocopherol acetate in pharmaceutical preparation on silica gel with chloroform - cyclohexane 11:9. Quantitative determination by absorbance measurement at 272 nm. The hRf values for tocopherol acetate and its related substance were 47 and 38, respectively. Limits of detection and quantification were 50 and 150 ng/zone, respectively. The intermediate/inter-day/intra-day precision was below 1.4 % (n=3). Recovery was between 99.8 and 101.5 %, respectively. A better separation of tocopherol acetate was obtained using NP-TLC technique than by RP-TLC technique.