J. AOAC Int. 93, 904-910 (2010). HPTLC of imipramine hydrochloride and chlordiazepoxide on silica gel with carbon tetrachloride - acetone - triethylamine (pH 8.3) 20:10:1 in a twin-trough chamber after saturation for 30 min at 25 °C. Quantitative determination by densitometry in absorbance mode at 240 nm. Linearity was between 50-600 and 20-240 ng/zone with mean accuracies of 99.5 and 100.6 % for imiprazine hydrochloride and chlordiazepoxide, respectively. The hRf value of imipramine was 73 and of chlordiazepoxide 32. The %RSD values of intra-day and inter-day precision were between 0.7-1.4 % and 0.4-1.2 % for imipramine and 0.8-1.7 % and 0.7-1.3 % for chlordiazepoxide.

J. Planar Chromatogr. 24, 428-434 (2011). HPTLC of 6-benzyl-, 6-methyl-, and 6-propyl-2-thiouracil and spiked urine samples on silica gel with methanol in a horizontal chamber saturated for 15 min at ambient temperature. Detection by spraying with a freshly prepared mixture of 4 % sodium azide and 1 % starch solution adjusted to pH 5.5, followed by exposure to iodine vapor for 5 s. Quantitative evaluation by use of an office scanner at 300 dpi resolution. The images were inverted and stored in the form of 24-bit-true color images, which were analysed by TLSee software. The determination range was 7-16 pmol/zone, 80-160 nmol/mL urine, or 133-266 nmol/mL serum. The recovery was between 93-106 %. The LOQ was 4 pmol/zone for the studied thiouracils in three investigated matrices.

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).

Chromatogr Sci. 50 (3), 157-161 (2012). Study of the lipophilicity of 12 new synthesized derivatives, the first eight compounds have as a basic chemical structure aryliden–hydrazino-selenazoles and the second group of the three compounds belongs to aroyl–hydrazinoselenazoles. HPTLC on RP-18 with methanol–water mixtures in different ratios. The linear correlation between RMw and the methanol–water ratios showed high values for the correlation coefficient. Determination of the chromatographic hydrophobic index by using the ratio –RMw/S, giving the values ranged between 99 and 73, and a good linear correlation between RMw and the slope. The log P values are also calculated. Formation of the matrices with RMw and log P and a principal component analysis (PCA) was implemented. Extraction of the information from PCA by plotting the obtained matrices. The compounds can be grouped by analyzing the scores into one containing nine compounds, and other containing three compounds, each group of compounds with the same basic chemical structure.

J. Planar Chromatogr. 25, 77-80 (2012). HPTLC of gemcitabine on silica gel with toluene - methanol - chloroform 6:6:5. Quantitative determination by absorbance measurement at 268 nm. The hRf value of gemcitabine was 48. Linearity was in the range of 500-3000 ng/band. Intraday and interday precisions (%RSD) were 1.4-1.6 % and 1.6-1.8 %, respectively. Recovery was found to be in the range of 98.3-101.8 %.

J. Liq. Chromatogr. Relat. Technol. 35, 524-532 (2012). HPTLC of atorvastatin calcium (1), ezetimibe (2), and fenofibrate (3) in tablet on silica gel with toluene – chloroform – methanol 23:15:7 + 1 drop glacial acetic acid. Quantitative determination by absorbance measurement at 253 nm. The hRf values of active agents (1) - (3) were 20, 33 and 80, respectively. Linearity was 200-800 ng/zone for (1) and (2) and 4-16 µg/zone for (3). The intermediate/inter-day/intra-day precision was below 1.1 % for (1), 1.3 % for (2) and 1.5 % for (3) (n=6). The limits of detection and quantification were 19 and 59 ng/zone for (1), 23 and 68 ng/zone for (2), and 1449 and 4390 ng/zone for (3), respectively. Recovery (by standard addition) was between 99.1 and 99.8 % for compounds (1) to (3).

J. Liq. Chromatogr. Relat. Technol. 35, 499-510 (2012). HPTLC of desvenlafaxine in dosage forms on silica gel with ethyl acetate - toluene - methanol 14:4:1 + 1 drop ammonia. Quantitative determination by absorbance measurement at 228 nm. The hRf value of desvenlafaxine was 48 and selectivity regarding matrix was given. Linearity was between 100 and 1000 ng/spot. The intermediate/inter-day/intra-day precision was below 0.2 % (n=6). The limits of detection and quantification were 10 and 100 ng/spot, respectively. Recovery (by standard addition) was between 97.9 and 99. 1%.

Quim. Nova. 35, 541-545 (2012). HPTLC of isoorientin on silica gel with ethyl acetate - formic acid - water 9:1:1. Detection by dipping into a solution of diphenylboric acid-2-aminoethyl ester (100 mg) and PEG 400 (500 mg) in methanol (10 mL). Quantitative determination by fluorescence measurement at 366 nm. The HPTLC method (120 min) was almost seven times faster than the HPLC method (700 min). The amount of solvent consumed in the HPTLC method (12 mL) was almost eight-fold less than that used in the HPLC method (98 mL), indicating that HPTLC is an alternative technique for analyzing large numbers of samples.