J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (7), 854-856 (2005). TLC of chenodeoxycholic acid in Hedan tablets on silica gel with n-hexane - ethyl acetate - acetic acid - methanol 20:25:2:3. Detection by spraying with 10 % H2SO4 in ethanol followed by heating at 105 ºC until the spots are visualized. Quantification of chenodeoxycholic acid by densitometry at 375 nm. Validation of the procedure by investigation of its linearity range (0.47 - 2.33 µg/spot, R = 0.9992); of its repeatability (3.3 %, n = 5); of its precision (3.9 %, n = 5 within plate and 4.7 % n= 5 plate-to-plate); and its standard addition recovery (98.4%, RSD = 2.5 %, n = 5).

Indian Drugs 42 (9), 600-603 (2005). HPTLC of cinnarizine and domperidone in tablets, on silica gel with toluene - ethyl acetate - methanol 14:1:5. Quantitative determination by absorbance measurement at 271 nm. Rf values of cinnarizine was 0.85 and of domperidone 0.4. Linearity was observed in the range of 0.1-0.4 for cinnarizine and 0.075-0.3 µg/µL for domperidone. The recoveries were in the range of 98.95-100.25 %. The tablet matrix did not interfere with the assay.

12. Isolation and identification of an isomeric impurity in danazol. Pharm. Research 12, 295-298 (1995). TLC of isodanazol according to The United States Pharmacopoeia XXII, 1990, pp. 379-380 and K. Ferenczi-Fodor, Z. Végh, Z. Pap-Sziklay, J. Planar chromatogr. 6, 198-203 (1993). Ferenczi-Fodor described a validated method for the selective determination of three individual impurities in danazol based on TLC-densitometric measurement at 252 nm. The Rf values of danazol and isodanazol in the TLC systems of USP XXII are 0.29 and 0.33, respectively, while in the system of Ferenczi-Fodor et al. 0.47 and 0.58.

J. Planar Chromatogr. 19, 427-431 (2006). HPTLC of sildenafil citrate on silica gel, pre-washed with methanol, with toluene - acetone - methanol 3:1:1 in a saturated twin-trough chamber. Quantitative determination by absorbance measurement at 312 nm. The method was validated in accordance with ICH guidelines on the validation of analytical methods.

J. Liq. Chromatogr. Relat. Technol. 28, 267-275 (2005) . TLC of allylestrenol on silica gel in a twin-trough chamber with n-hexane - ethyl acetate - dichloromethane 45:10:1. Detection by spraying with anisaldehyde-sulfuric acid reagent followed by heating at 100 °C for 5 min. Quantitative determination by absorbance measurement at 609 nm.

J. Liq. Chromatogr. & Relat. Technol. 29, 2863-2873 (2006). HPTLC of nifedipine (1,4-dihydro-2,6-dimethyl-4-(2-nitro-phenyl)-3,5-pyridinedicarboxylic acid dimethyl ester) on silica gel in horizontal chamber with n-hexane - ethyl acetate - acetone 6:3:2. Quantitative determination by absorbance masurement at 335 nm.

J. Planar Chromatogr. 20, 423-427 (2007). TLC of 8 essential amino acids (L-lysine, L-valine, L-isoleucine, DL-threonine, L-methionine, L-leucine, DL-phenylalanine, DL-tryptophan) on silica gel with 17 mobile phases, of which the mixed aqueous surfactant solution Triton X-100 (0.001 mM) - sodium dodecyl sulfate, 0.081 mM - acetone 1:1:5 was identified as the best mobile phase for specific separation of lysine. Visualization by spraying with 0.3 % ninhydrin in acetone. Limit of detection was 0.5 µg/zone.

59th Indian Pharmaceutical Congress F-57, 403, (2007). HPTLC of duloxetine hydrochloride on silica gel with chloroform - methanol 4:1. Densitometric evaluation at 217nm. The hRf value of duloxetine was 45. The limit of detection and quantification was 120 and 240 ng/zone, respectively. Degradation products (acid, alkali, oxidative and thermal) were well separated from the main component. The proposed HPTLC method was routinely applied for identification and quantification of the drug in the formulation.