J. Planar Chromatogr. 24, 218-221 (2011). HPTLC of alfuzosin hydrochloride (ALF) and dutasteride (DUTA) in the bulk drug and in a tablet formulation on silica gel with toluene - methanol - dichloromethane 6:1:1 + 1 drop triethylamine. Quantitative determination by densitometry at 247 nm. The hRf of ALF was 46 and of DUTA 65. Linearity was between 300-600 ng/band for ALF and 500-100 ng/band for DUTA. LOD and LOQ were 100 and 200 ng/band for ALF and 300 and 400 ng/band for DUTA. Precisions (%RSD) for repeatability of application were 1.8 and 1.5 % for ALF and 1.5 and 1.4 % for DUTA. The inter-day and intra-day precision (%RSD, n = 6) was 1.0 and 0.9 % for ALF and 1.7 and 0.8 % for DUTA, respectively. Recovery (by standard addition) was between 98.9-101.6 % for both compounds.

Food Chemistry 132, 549-553 (2012).. New HPTLC-based method to examine quantitatively the free radical scavenging activity of plant extracts. After chromatographic separation of polar compounds, and immersion of HPTLC plates in methanolic DPPH radical reagent, bleaching was observed and recorded using a photo camera and data analysis was carried out using an image processing software. The method is simple, fast and efficient for free-radical scavenging activity analysis of phytochemicals and crude plant extracts.

J. Liq. Chromatogr. Relat. Technol. 34, 1925-1937 (2011). HPTLC of p-hydroxy benzoic acid (1), chrysoplenol-D (2), p-methoxy benzoic acid (3) and casticin (4) in the aerial parts of Vitex trifolia on silica gel with chloroform - methanol 24:1 + 1 drop formic acid. Quantitative determination by absorbance measurement at 254 nm. The hRf values of compounds (1) - (4) were 25, 31, 63 and 87, respectively. LOD and LOQ were found to be 18-58 ng/zone for (1), 39-132 ng/zone for (2),15-52 ng/zone for (3) and 33-111 ng/zone for (4). Repeatability and reproducibility (%RSD) for (1)-(4) were found in the range of 0.8-1.2 % and 1.2-1.3 %, respectively. Recoveries were obtained in the range of 94.0-101.1 %, 97.8-102.0 %, 95.1-100.1 %, and 97.6-100.3 % for compounds (1) - (4), respectively.

J. Planar Chromatogr. 25, 314-319 (2012). HPTLC of 4-odemethylpodophyllotoxin (1), podophyllotoxin (2), kaempferol (3), podophyllotoxone (4), and deoxypodophyllotoxin (5) in the rhizomes of Podophyllum hexandrum on silica gel with toluene - ethyl acetate 2:1 + 1 drop glacial acetic acid. Quantitative determination by absorbance measurement at 254 nm. Linearity was in the range of 1-8 µg/band for (1), (2) and (4) and 2-10 µg/band for (3) and (5). The intermediate/inter-day/intra-day precision was below 2 %. Average recovery for all (1) to (4) were between 96.4 and 101.8 %.

J. Liq. Chromatogr. Relat. Technol. 35, 1429-1443 (2012). HPTLC of azorubin (1) and sunset yellow (2) in powders for jelly desserts on silica gel with n-butyl alcohol - acetic acid - ethanol - water 10:2:1:5. Quantitative determination by absorbance measurement at 485 nm for (2) and 515 nm for (1). The hRf values of (1) and (2) were 45 and 53, and selectivity regarding matrix was given. Linearity was between 100-400 ng/zone for (1) and 200-450 ng/zone for (2). The %RSD values for repeatability studies were below 2. The limits of detection and quantification were 9 and 19 ng/zone, for (1) and 11 and 23 ng/zone for (2), respectively. Recovery was higher than 96.9 % for (1) and 95.7 % for (2).

J. Planar Chromatogr. 25, 445-449 (2012). HPTLC of bergenin in the stem-bark and roots of Mallotus phillippensis on silica gel with ethyl acetate - methanol - acetic acid - formic acid 16:2:1:1. Quantitative determination by absorbance measurement at 284 nm and by TLC-MS using the TLC-MS Interface. The hRf of bergenin was 49. Linearity was in the range of 100-600 ng/zone. Limits of detection and quantification were 29, 37 and 98 ng/zone, respectively. Intermediate intra-day/inter-day precision was 1.1 % (n=6). Recovery was between 96.6 and 98.9 %.

J. Planar Chromatogr. 25, 559-565 (2012). HPTLC of zafirlukast on silica gel with toluene - methanol - acetone 7:2:1. Quantitative determination by absorbance measurement at 240 nm. Linearity was in the range of 50-400 ng/zone. Limits of detection and quantification were 16 and 50 ng/zone, respectively.

J. Planar Chromatogr. 25, 368-373 (2012). HPTLC of rebamipide on silica gel with toluene - methanol - triethylamine 16:9:1. Quantitative determination by absorbance measurement at 230 nm. The hRf of rebamipide was 59. Linearity was in the range of 100-600 ng/band. Limits of detection and quantification were 6 and 18 ng/band, respectively. Intermediate intra-day/inter-day precision was below 1.7 % (n=3). Recovery (by standard addition) was between 100.1 and 100.9 %. The proposed HPTLC method is equivalent to a reported HPLC method.