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.

J. Planar Chromatogr. 24, 337-343 (2011). TLC of tenoxicam and pyridine-2-amine on silica gel with ethyl acetate - toluene - butylamine 2:2:1 with chamber saturation for 15 min at room temperature. Quantitative determination by absorbance measurement at 288 nm. The hRf value was 52 and 64 for tenoxicam and pyridine-2-amine, respectively. Linearity was between 35-1820 mg/mL for tenoxicam and 10-500 mg/mL for pyridine-2-amine. LOD and LOQ were 0.9 and 2.6 mg/band for tenoxicam and 0.1 and 0.3 mg/band for pyridine-2-amine. The recovery was 99.0-99.9 % for tenoxicam and pyridine-2-amine. The %RSD did not exceed 1 % at any level.

J. Planar Chromatogr. 25, 344-348 (2012). HPTLC of two oil-soluble sunscreens, namely avobenzone (1) and octyl salicylate (2) and a water-soluble sunscreen, namely phenylbenzimidazol sulfonic acid (3) on silica gel with cyclohexane - diethyl ether 5:1 for (1) and (2) and ethyl acetate - ethanol - water 14:7:6 for (3). Quantitative determination by absorbance measurement at 300 nm for (2) and (3), and 360 nm for (1). Limits of detection and quantification were found to be 30 and 80 ng/zone for (1), and 20 and 60 ng/zone for both (2) and (3).