Chinese J. of Northwest Pharm. 26 (5), 324-327 (2011). TLC of the extracts of Kelu Oral Liquid on silica gel 1) for Ephedrae herba, with chloroform - methanol - concentrated ammonia 40:7:1, detection by spraying with 5 % ninhydrin in ethanol and heating at 105 °C, identification by fingerprint comparison with ephedrine/pseudoephedrine hydrochloride; 2) for Scutellariae radix, with ethyl acetate - butanone - formic acid - water 5:3:1:1, detection by spraying with 10 % FeCl3 in ethanol and heating at 105 °C, identification by fingerprint comparison with astragaloside IV; 3) for menthol and Tatarian Aster root, with petroleum ether (60-90 °C) - ethyl acetate 9:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, identification by fingerprint comparison menthol and shionone; 4) for Glycyrrhizae radix, with ethyl acetate - formic acid - glacial acetic acid - water 15:1:1:2, detection under UV 365 nm after spraying with 10 % sulfuric acid in ethanol and heating at 105 °C, identification by fingerprint comparison with glycyrrhizic acid ammonium salt; 5) for Loquat leaf, with cyclohexane - chloroform - ethyl acetate - glacial acetic acid 40:10:16:1, detection by spraying with 20 % phosphomolybdic acid in ethanol and heating at 105 °C, identification by fingerprint comparison with ursolic acid; 6) for Fritillaria cirrhosa D. Don, with ethyl acetate - methanol - concentrated ammonia 18:2:1, detection by spraying with 5 % potassium iodobismuthate and 0.2 % sodium nitrite solution, identification by fingerprint comparison with peiminine.

Research Journal of Pharmaceutical, Biological and Chemical Sciences 2(1), 6-11 (2011). HPTLC of tolterodine tartarate on silica gel with acetonitrile - water - formic acid 50:50:3 with chamber saturation for 15 min. Quantitative determination by densitometry in absorbance mode at 281 nm. The content of tolterodine tartarate in the formulation was calculated and found to be 99.1 %. The recovery (by standard addition) was between 99.1-100.1 %. LOD was 21 and LOQ 53 ng/zone. The intra-day and inter-day precisions (%RSD) were 0.05 and 0.08 %, respectively.

J. AOAC Int. 93, 787-791 (2010). HPTLC of omeprazole on silica gel with chloroform - methanol 9:1 in a twin-trough chamber after saturation for 20 min. Quantitative determination by absorbance measurement at 302 nm. The hRf value of omeprazole was 39. Linearity was between 50 and 3000 ng/band. The intra-day and inter-day precision was 0.4-0.5 and 0.8-0.9 % (n = 2). The recovery was 98.4-99.1 %. LOD and LOQ were 8 and 24 ng/zone, respectively.

J. Planar Chromatogr. 24, 520-523 (2011). HPTLC of streptomycin and amoxicillin, ampicillin, cefixime, cephalexin, cloxacillin, co-trimoxazole, doxycycline, erythromycin, gentamycin, metronidazole, tetracycline on titanium(IV) silicate coated plates with 0.5 M potassium bromide and ethanol 9:1 in a twin-trough chamber. Detection by spraying with a fresh 2 % solution of sodium carbonate and 5 % sodium nitroprusside dihydrate in 1 % acetaldehyde 1:1 or iodine solution (2 g iodine and 3 g potassium iodide in 100 mL water). Quantitative determination by densitometry in absorbance mode at 359 nm. The recovery was 97.9 %. LOD and LOQ were 2 and 12 ng/zone, respectively.

J. Planar Chromatogr. 24, 306-311 (2011). HPTLC of ethanolic leaf extracts of A. squamosa, with rutin and isoquercitrin as standards, on silica gel (prewashed with methanol) with ethyl acetate - formic acid - glacial acetic acid - ethyl methyl ketone - water 50:7:3:30:10 with chamber saturation for 30 min at room temperature (25 +/- 2°C) and a relative humidity of 50 +/- 5 %. Quantitative determination by densitometry at 366 nm. Linearity was between 200-1600 ng/band for both rutin and isoquercitrin. The robustness of the method (%RSD) was 1.9-2.9 % for rutin and 1.5-2.3 % for isoquercitrin, respectively. The instrumental precision (%RSD) was 0.9 and 0.3 % for rutin and isoquercitrin, respectively. The intra-day and inter-day precision (%RSD) was less than 3 % in all cases. LOD and LOQ was 75 and 100 ng/band for rutin and 40 and 80 ng/band for isoquercitrin, respectively. The hRf value was 32 for rutin and 58 for isoquercitrin. Recovery (by standard addition) was found to be 96-107 %.

J. Planar Chromatogr. 24, 72-76 (2011). HPTLC of sennoside A and B and gallic acid on silica gel with toluene - ethy acetate - formic acid - methanol 8:8:4:5. Quantitative analysis by densitometry at 270 nm. Linearity was between 114-427 ng/zone for sennosides A and B and 100-375 ng/zone for gallic acid. For sennosides A and B and gallic acid, hRf values were 26, 21 and 80, correlation coefficients were 0.95, 0.998, and 0.997, method precisions (%RSD, n = 6) were 1.1, 1.1 and 0.9 %, recoveries were 96.3-97.2 %, 98.1-100.8 % and 97.1-98.1 %, respectively. LOD andLOQ was 30 and 25 ng/zone for sennoside A, 20 and 99 ng/zone for sennoside B, and 66 and 82 ng/zone for gallic acid.

J. Planar Chromatogr. 24, 513-519 (2011). TLC of nabumetone (4-(6-methoxy-2-naphthyl)butan-2-one) on silica gel with n-hexane - chloroform - glacial acetic acid 4:1:1 with chamber saturation for 15 min. Quantitative determination by densitometry in absorbance mode at 270 and 330 nm. LOD and LOQ ranged from 0.23-1.00 µg/band. The recovery was between 98.9-101.7 % (at measurement wavelength 270 nm) and 99.6-101.7 % (at measurement wavelength 330 nm). The precision (%RSD) was below 2 % for all concentration levels. Linearity was between 0.3-3.5 µg/band. The hRf value was 72.

The case of determination of rosmarinic acid in different matrices. J. Chromatogr. A 1220, 156-161 (2012). Description of a new method for determination of rosmarinic acid in different matrices by HPTLC on silica gel with toluene – ethyl formate – formic acid 6:4:1. Quantification by densitometry in absorbance mode at 330 nm. The influence of the main HPTLC operative parameters was figured out in view of a more stringent validation process. Together with the fundamental HPTLC instrumentation an automatic developing chamber is mandatory as it allows for control of the relative humidity and the saturation conditions and thus assures reproducibility. Several commercial preparations containing rosmarinic acid in different amounts were tested and rosmarinic acid in the range of 132-660 ng/band was found. The %RSD of repeatability and intermediate precision did not exceed 2.