J. AOAC Int. 93, 1836-1843 (2010). HPTLC of 1) lamivudine-zidovudine on silica gel with ethyl acetate - toluene - methanol 12:5:3, quantitative determination by absorbance measurement at 289 nm; of 2) metronidazole with ethyl acetate - ammonia 50:1, quantitative determination by absorbance measurement at 313 nm; of 3) neviparine with ethyl acetate - toluene 3:1, quantitative determination by absorbance measurement at 289 nm; and of 4) quinine with ethyl acetate - toluene - acetone 22:3:5, quantitative determination by absorbance measurement at 327 nm in a twin-trough chamber lined with wetted filter paper and saturated for 20 min. The average repeatability (within-laboratory) was 1.9 %, with 73 % less than 2 % and 97 % at 2.6 % or less. The average reproducibility (among-laboratory) was 2.7 %. Mean hRf values for lamivudine, metronidazole, neviparine, quinine, and zidovudine were 19, 28, 34, 33, 57.

J. Planar Chromatogr. 24, 376-380 (2011). HPTLC of stem bark extracts from D. melanoxylon and lupeol and betulin on silica gel, prewashed with methanol, with ethyl acetate - hexane 9:41 with chamber saturation for 3 min at 29 +/- 4 °C and 65 +/- 5 % relative humidity. The hRf value was 46 and 25 for lupeol and betulin, respectively. Quantitative determination by densitometry in absorption mode at 560 nm for lupeol and 510 nm for betulin. Detection by derivatization with 5 % methanol-sulfuric acid reagent. The LOD and LOQ was 40 and 100 ng/zone for lupeol and 50 and 100 ng/zone for betulin, respectively. The instrument precision and repeatability (n = 6) were 0.8 and 1.3 % for lupeol and 1.1 and 1.2 % for betulin, respectively. The linearity range was 100-500 ng/zone for both lupeol and betulin. The intra-day and inter-day precision was 1.1-1.7 % and 1.3-2.0 % for lupeol and 0.8-1.9 % and 1.9-2.2 % for betulin.

J. AOAC Int. 94, 1422-1426 (2011). HPTLC of eleutherosides B, E, and E1 in the fruits and leaves of E. senticosus and five other species of Eleutherococcus species after extraction with SPE, on silica gel in the horizontal chamber with saturation for 20 min, with a two-step development with 1) chloroform - methanol - water 70:30:4 and 2) chloroform - methanol - toluene - ammonium hydroxide 9:6:3:2. Detection by immersion in Liebermann-Burchard reagent for 1 s and heating at 110 °C for 10 min. The hRf values for the eleutherosides E, B, and E1 were 43, 53, and 66, respectively.

International Journal of Pharmacy and Pharmaceutical Sciences 3(2), 85-89 (2011). TLC of andrographolide on silica gel with toluene - ethyl acetate - formic acid 10:9:1. Densitometric evaluation at 235 nm before derivatization. Evaluation of the fingerprint profile at 254 nm and after derivatization at 366 nm by spraying with anisaldehyde-sulfuric acid reagent followed by heating at 110 °C.

Journal of Pharmacy Research 4(5), 1538-1540 (2011). HPTLC of duloxetine hydrochloride on silica gel with ethyl acetate - carbon tetrachloride - methanol - toluene - glacial acetic acid 20:12:5:35:5. The hRf value was 35. Quantitative determination at 295 nm. The method was found to be linear in the range of 200-600 ng/band with a mean recovery of 100.2 %. The drug was subjected to different stress conditions (acid, alkali, thermal, photolytic, and oxidative) and the degradation products were well resolved from the main drug.

J. Liq. Chromatogr. Relat. Technol. 34, 1502-1517 (2011). HPTLC of irinotecan in bulk drug and injectable formulations on silica gel with acetone - ethyl acetate 17:3 + 1 drop acetic acid. Quantitative determination by absorbance measurement at 366 nm. The hRf of irinotecan was 31. Linearity was 50-500 ng/zone. The LOD and LOQ was found to be 10 and 33 ng/zone. The intra-day precision was 4.3 % (n = 6) and inter-day precision over three different days was 3.1 %. Intra-day and inter-day accuracy were 96.9-100.3 % and 96.5-98.7 %, respectively. Recovery (by standard addition) ranged from 94.6-101.4 %.

J. Planar Chromatogr. 24, 507-512 (2011). HPTLC of flavonoids (quercetin and kaempferol) and biflavonoids (sciadopitysin, ginkgetin, and bilobetin) in aqueous methanolic extracts of Ginkgo biloba on RP-18 by double development with 1) acetonitrile - water - methanol - formic acid 20:20:1:0.005 and 2) acetonitrile - water - methanol - formic acid 20:17:1:0.005. Quantitative determination by densitometry in absorption mode at 254 nm. LOD and LOQ were in the range of 0.12-0.37 and 0.60-1.85 µg/zone, respectively. Linearity was found over the concentration range of 0.5-4.0 µg/zone for quercetin, kaempferol, sciadopitysin, ginkgetin, and bilobetin with correlation coefficients r = 0.9990, 0.9922, 0.9939, 0.9974, and 0.9706, respectively. Average recoveries were in the range of 97.7-100.4 %.

Journal of Pharmacy Research 4(5), 1353-1355 (2011). HPTLC of methanolic extracts of Aegle marmelos fruit pulp on silica gel with toluene - ethyl acetate - glacial acetic acid 70:30:1. Densitometric quantification of marmelosin at 310 nm. The method was linear in the range of 50-350 ng/band. The method was used to determine the marmelosin content of pulp, unripe pulp, seeds, leaves, rind, outer stain and inner stain.