J. Liq. Chromatogr. Relat. Technol. 35, 2753-2764 (2012). HPTLC of melitracen hydrochloride (1) and flupentixol hydrochloride (2) on silica gel with methanol - chloroform - toluene 2:9:9 + 1 drop ammonia. Quantitative determination by absorbance measurement at 291 nm. The hRf value of compounds (1) and (2) were 53 and 34 and selectivity regarding matrix was given. Linearity was in the range of 1600-6400 ng/band and 80-320 ng/band for (1) and (2), respectively. Limit of detection was found to be 27 ng/band and 5 ng/band for (1) and (2), respectively. Limit of quantification was found to be 82 ng/band and 14 ng/band for (1) and (2), respectively. The intermediate/inter-day/intra-day precision was below 0.2 % for (1) and 1.1 % for (2) (n=3). Recovery (by standard addition) was between 99.1 and 101.8 % for both (1) and (2). The method showed comparable results with HPLC.

J. Planar Chromatogr. 25, 456-462 (2012). HPTLC of loratadine (1) and desloratadine (2) on silica gel with methanol + 1 drop ammonia. Quantitative determination by absorbance measurement at 254 nm. The hRf values of (1) and (2) were 76 and 20, respectively. Linearity was in the range of 250-850 ng/band for (1) and 100-1000 ng/band for (2). Limits of detection and quantification were 90 and 250 µg/band for (1) and 30 and 100 µg/band for (2), respectively. Intra- and inter-day precisions were found to be less than 2 %. Recoveries were between 97.8 and 101.5 % for both (1) and (2).

J. Liq. Chromatogr. Relat. Technol. 36, 2395-2404 (2013). HPTLC of carbidopa (1) and levodopa (2) in tablets on RP-18 with citrate buffer (pH 3.0) - methanol - formic acid 96:4:5. Detection by spraying with 0.02 % 2,2-diphenyl-1-picrylhydrazyl solution in ethanol (DPPH radical reagent). The hRf values of compounds (1) and (2) were 39 and 63, respectively. Linearity was in the range of 50-300 ng/zone for both (1) and (2). Intermediate precision was below 3.7 %. LOD and LOQ were 20.5-60.7 ng/zone for (1) and 27.8-61.1 ng/zone for (2), respectively. Recovery (by standard addition) was 99.6-95.4 % for both.

J. Liq. Chromatogr. Relat. Technol. 37, 2784-2799 (2014). HPTLC of atorvastatin (1), ezetimibe (2) and fenofibrate (3) on silica gel with toluene – methanol – triethylamine 16:3:1. Quantitative determination by absorbance measurement at 245 nm. The hRF values for (1) to (3) were 10, 20 and 80, respectively. Linearity was in the range of 100-350 ng/zone for (1) and (2) and 1600-5600 ng/zone for (3). The intermediate/interday/intra-day precisions were below 1 % (n=3). The LOD and LOQ were 60 and 90 ng/zone for (1), 80 and 100 ng/zone for (2) and 90 and 150 ng/zone for (3), respectively. Recoveries were in the range of 97.6-102.6 %.

J. Liq. Chromatogr. Relat. Technol. 38, 1639-1659 (2015). Systematic review of different chromatographic methods for the analysis of proton pump inhibitors. The review describes the application of HPTLC for the analysis of omeprazole in biological fluids such as plasma, on silica gel with n-butanol - ammonia - water 14:1:15 (1) or chloroform - methanol 15:1 (2) and quantitative determination at 280 nm for (1) or 286 nm for (2).

J. Planar Chromatogr. 29, 190-194 (2016). HPTLC of ranolazine in tablet formulations on silica gel with butanol – acetic acid – water 3:1:1. Quantitative determination by absorbance measurement at 270 nm. The hRF value of ranolazine was 56. Linearity was in the range of 100-400 ng/zone. Intermediate precisions were below 1.4 %. The LOD and LOQ were 15 and 50 ng/zone. Recoveries were between 98.2 and 101.1 %.

J. Liq. Chromatogr. Relat. Technol. 40, 813-831 (2018). Review of recent trends in analytical methodologies for impurity profiling and forced degradation of pharmaceutical drug and drug products used for the treatment of hypertension, including the application of HPTLC for the analysis of angiotensin receptor blockers.

J. Planar Chromatogr. 31, 280-289 (2018). HPTLC of prilocaine (1), lidocaine (2), O-toluidine (3) and 2,6-dimethylaniline (4) on silica gel with toluene – chloroform – ethanol – triethylamine 50:50:10:1. The hRf values for (1) to (4) were 27, 37, 58 and 67, respectively. Quantitative determination by absorbance measurement at 220 nm. Linearity ranged between 0.4-9.0 μg/zone for (1), 0.8-11.0 μg/zone for (2), 0.2-2.9 μg/zone for (3) and 0.1-1.4 μg/zone for (4). LOD and LOQ were 1.5 and 4.4 μg/mL for (1), 5.1 and 15.5 μg/mL for (2), 1.3 and 4.1 μg/mL for (3) and 1.0 and 3.1 μg/mL for (4). The intermediate precision was <1 % (n=3). Average recovery was 100.3 % for (1), 100.9 % for (2), 99.8 % for (3) and 100.3 % for (4).