J. Planar Chromatogr. 24, 82-87 (2011). TLC of crude extracts and madecassoside, asiaticoside, madecassic acid, and asiatic acid on silica gel with concentration zone with chloroform - glacial acetic acid - methanol - water 15:8:3:2; the hRf value was 45, 55, 94, and 97, respectively. Detection by spraying with anisaldehyde-sulfuric acid reagent, followed by heating at 95 °C for 10 min or until the colored zones appeared. The correlation coefficients were between 0.9904 and 0.9982 and linearity was in the range of 1.25-10 nmol, corresponding to approximately 0.5-5 µg/zone for the acids and 1.2-10 µg/zone for the glycosides. The LOD and LOQ was 300 and 720 ng/zone for the sapogenin and saponin, respectively, and 500 and 1200 ng/zone. The average precision was less than 4 % for standards and between 4-6 % for samples.

J. Liq. Chromatogr. Relat. Technol. 34, 2548-2464 (2011). HPTLC of tocopherol acetate (1) and tocopherol (2) in oral fluid vitamin E on silica gel with chloroform - cyclohexane 11:9. Quantitative determination by absorbance measurement at 202 nm for (1) and 272 nm for (2). The hRf values of (1) and (2) were 47 and 38, respectively. Linearity was in the range of 2-8 µg/band for (1) and (2). Limits of detection and quantification were found to be 50 and 150 ng/zone for (1). Precision was below 2 %. The intermediate/inter-day/intra-day precision was 0.4 % (n = 6). Recovery (by standard addition) was in the range between 99.8-101.5 %. Tocopherol acetate was better separated from tocopherol using normal phase TLC than by reversed phase TLC.

J. Planar Chromatogr. 24, 264-267 (2011). TLC of crebanine on silica gel with toluene - ethyl acetate - methanol 14:3:3 in a twin-trough chamber saturated for 1 h at 25 +/- 2 °C. Detection under UV light at 254 nm. Quantitative determination by densitometry in absorbance mode at 286 nm. The method precision (%RSD, n = 3) and the instrument precision (%RSD, n = 6) were 0.9 and 0.5 %, respectively. The repeatability (%RSD, n = 5) was 0.8; the accuracy as average recovery was 100.1 %. The limit of detection and quantification was 10 and 15 ng/zone, respectively. Linearity was between 100-500 ng/zone. The hRf value was 54.

J. Planar Chromatogr. 23, 315-319 (2010). HPTLC of polyphenols (extracted from Quercus robur) and quercetin, chlorogenic acid, gallic acid, and rutin as standards on silica gel with ethyl acetate - water - formic acid 87:3:10 in an unsaturated twin-trough chamber. Detection by spraying with 1 % 2-aminoethyl diphenylborinate (natural products reagent) followed by 2 % polyethylene glycol 4000 solution as well as by spraying with 2 % phosphomolybdic acid reagent followed by heating at 120 °C for 5 min. Evaluation by densitometry in absorption mode at 700 nm.

J. Planar Chromatogr. 24, 166-171 (2011). HPTLC of brimonidine tartrate as the bulk drug and in formulations on silica gel with methanol - toluene - triethylamine 10:35:2. The hRf value was 48. Quantitative determination by densitometry in absorbance mode at 247 nm. Linearity was between 100 and 600 ng/band (r² = 0.9965). LOD and LOQ were 9 and 28 ng/band, respectively. The intra-day and inter-day precision (%RSD, n = 3) was 1.1-1.2 % and 0.5-1.0 %, respectively. Recovery was between 98.7-100.4 %. The repeatability of application (%RSD, n = 6), was 1.6 %.

J. Planar Chromatogr. 24, 23-29 (2011). TLC of cephalexin, cefadroxil, cefazolin, cefaclor, cefuroxime axetil, ceftriaxone, and cefotaxime on silica gel with chloroform - ethyl acetate - glacial acetic acid - water 4:4:4:1. Quantitative determination by absorbance measurement at 275 nm. Accuracy was in the range of 98.3-100.8 % and precision (%RSD) was 0.4-2.5 %. LOQ were 0.1 µg/L for cefuroxime and 2.8 µg/L for cefotaxime. The method was highly reproducible with inter- and intra-day precisions between 0.24-0.25 %.

J. Chil. Chem. Soc. 56, 702-705 (2011). HPTLC of lamivudine (1) and tenofovir disoproxil fumarate (2) in bulk drug and pharmaceutical dosage form on silica gel with chloroform - methanol - toluene 4:1:1. Quantitative determination by absorbance measurement at 265 nm. The hRf values of (1) and (2) were 27 and 51, respectively. Linearity was between 60-210 ng/zone for both. LOD and LOQ were found to be 20 and 40 ng/zone for (1) and 30 and 60 ng for (2). The intermediate/interday/intra-day precision was 0.6 % (n=6). Recovery (by standard addition) for (1) and (2) was between 98-102 %. The HPTLC method is suitable for routine analysis of lamivudine and tenofovir in pharmaceutical dosage form.

J. Planar Chromatogr. 24, 77-81 (2011). HPTLC of belleric acid on silica gel, prewashed with methanol, with toluene - ethyl acetate - methanol - formic acid 15:15:7:1 in a saturated chamber at 22 °C and 65 % relative humidity. Quantitative determination by absorbance measurement at 205 nm. Average recovery was 98.7-100.9 %. Linearity was between 250 and 1250 ng/zone. Repeatability and intermediate precision (%RSD) were 1.2 and 1.5 %, respectively. LOD and LOQ were 49 and 148 ng/zone, respectively. The hRf value of belleric acid was 35.