J. Planar Chromatogr. 25, 65-71 (2012). HPTLC of dapsone in presence of its oxidative degradants on silica gel with acetate - toluene 1:1. Quantitative determination by absorbance measurement at 289 nm. Linearity was in the range of 0.5-6.0 µg/zone. Recovery was 99.4 %. The method showed comparable results to a validated HPLC method.

J. Liq. Chromatogr. Relat. Technol. 36, 537-548 (2013). HPTLC of lamotrigine in tablets on silica gel with toluene - acetone - ammonia 6:14:1. Quantitative determination by absorbance measurement at 312 nm. The hRf value of lamotrigine was 55. LOD and LOQ were 0.57 and 1.73 µg/mL, respectively. Intermediate precision was below 1.9 %. Average recovery (by standard addition) was 101.5 %. Comparable results were obtained as compared with a validated HPLC method.

J. Planar Chromatogr. 27, 294-298 (2014). HPTLC of amiloride hydrochloride (1) and torsemide (2) in dosage forms on silica gel with chloroform - methanol - ammonia 15:7:2. Quantitative determination by absorbance measurement at 286 nm. The hRF values for (1) and (2) were 46 and 24, respectively. Linearity was in the range of 50-300 ng/zone for (1) and 100-600 ng/zone for (2). The intermediate/inter-day/intra-day precision were below 4 % (n=3). The LOD and LOQ were 16 and 50 ng/zone for (1) and 33 and 100 ng/zone for (2), respectively. Recoveries for (1) and (2) were between 97.4 and 99.5 %.

Int. J. Pharm. 492, 109-119 (2015). HPTLC of sildenafil on silica gel with chloroform - ethanol 9:1. Quantitative determination by absorbance measurement at 254 nm.

CBS 114, 9-10 (2015). HPTLC of phosphodiesterase type 5 inhibitors Viagra (sildenafil), Levitra (vardenafil), Cialis (tadalafil) and their analogs (hydroxyacetildenafil, homosildenafil, thiohomosildenafil, acetildenafil, acetaminotadalafil, propoxyphenyl, hydroxyhomosildenafil, hydroxyhomosildenafil, and_x000D_
hydroxythiohomosildenafil) on silica gel with t-butyl methyl ether – methanol – 28 % ammonia 20:2:1 with chamber saturation, migration distance 70 mm. Detection under UV 254 and 366 nm. Densitometric evaluation by absorbance measurement at 232 nm. Identification of the substances based on their hRf values and distinctly different UV spectra.

J. AOAC Int. 100, 414-421 (2017). HPTLC of two binary mixtures containing pyridoxine hydrochloride (1) with either cyclizine hydrochloride (2) or meclizine hydrochloride (3) on silica gel with dichloromethane – acetone – methanol 14:2:1. Quantitative determination by absorbance measurement at 220 nm. The hRF values for (1-3) were 7, 25 and 80, respectively. Linearity was in the range of 0.2-5 μg/zone for (1) and 0.2-4 μg/zone for (2) and (3). The LOD and LOQ were 60 and 190 ng/zone for (1), 50 and 170 ng/zone for (2) and 60 and 170 ng/zone for (3), respectively. The intermediate precision was <2 % (n=3). Average recovery rate was 99.9 % for (1) and (3) and 100.1 % for (2).

J. Planar Chromatogr. 31, 477-487 (2018). HPTLC of thiocolchicoside on silica gel with toluene – acetone – water 3:15:2. Quantitative determination by absorbance measurement at 370 nm. The hRF value for thiocolchicoside was 53. Linearity was between 100 and 500 ng/zone. LOD and LOQ were 4 and 12 ng/zone. The intermediate precision was <2 % (n=3). Recovery was between 99.4 and 101.7 %.

J. Chromatogr. 299, 465-470 (1984). TLC separation of a mixture of benzodiazepines on silica with chloroform - acetone 9:1 (first direction), followed by in-situ acidic hydrolysis of the unresolved spots with sulfuric acid in methanol (15 %; 5 mL per component) and subsequent chromatography with dichloromethane - chloroform 1 :1 (second direction). Detection by UV 254 and 366 nm.