J. of Chromatogr. Sci. 58 (5), 411 - 417 (2020). Analysis of a binary mixture of silymarin (SR) and vitamin E (VE) acetate in their pure forms, pharmaceutical formulation and spiked human plasma, by HPTLC on silica gel with hexane - acetone - formic acid 140:60:3, detection at UV 215 nm, and quantification by densitometry. The linearity was 0.2 - 2.5 and 0.2 - 4.5 μg/band for SR and VE, respectively. Accuracy was 99.9 ± 1.2 % and 100.2 ± 1.6 % for SR and VE, respectively. The method was successfullly used for the determination of the studied drugs in their pharmaceutical formulation without any interference from excipients, and in spiked plasma samples. Statistical comparison of the results obtained by this HPTLC method showed no significant difference to the results obtained by the reported HPLC method.

J. of Chromatogr. Sci. 58 (5), 411 - 417 (2020). Analysis of a binary mixture of silymarin (SR) and vitamin E (VE) acetate in their pure forms, pharmaceutical formulation and spiked human plasma, by HPTLC on silica gel with hexane - acetone - formic acid 140:60:3, detection at UV 215 nm, and quantification by densitometry. The linearity was 0.2 - 2.5 and 0.2 - 4.5 μg/band for SR and VE, respectively. Accuracy was 99.9 ± 1.2 % and 100.2 ± 1.6 % for SR and VE, respectively. The method was successfullly used for the determination of the studied drugs in their pharmaceutical formulation without any interference from excipients, and in spiked plasma samples. Statistical comparison of the results obtained by this HPTLC method showed no significant difference to the results obtained by the reported HPLC method.

J. of Chromatogr. Sci. 58 (4), 303 - 308 (2020). Determination of dapoxetine hydrochloride (DAP) and tadalafil (TAD) in their binary mixtures either as raw materials or in pharmaceutical formulations, by HPTLC on silica gel with ethanol - ethyl acetate 1:9. Quantitative determination by densitometry at 222 nm. The linear range was 0.1 - 1.6 and 0.2 - 2.5 μg/band for dapoxetine and tadalafil, respectively, with accuracies of 98.9 % ± 0.6 and 99.3 6% ± 1.4, respectively.

J. of Chromatogr. Sci. 58 (1), 16 - 21 (2020). Development of a selective and sensitive method for the simultaneous determination of a new combination of quinfamide and mebendazole in bulk powder and in pharmaceutical formulation by HPTLC on silica gel with methanol - toluene 1:3. Quantitative determination by densitometry at 254 nm. Validation of the method according to ICH guidelines. Successful application for determination of quinfamide and mebendazole in tablets. Statistical comparison between the developed HPTLC method and a reported simultaneous equation spectrophotometric method showed no significant difference, proving the suitability for quality control testing of the studied drugs.

J. of Chromatogr. Sci. 57 (9), 799 - 805 (2019). Description of a method for the quantification of R, R-glycopyrronium bromide (GLY) and its related impurities in drug substance and drug product by HPTLC on silica gel with dichloromethane - methanol - formic acid 20:1:1. GLY and its related impurities (glycopyrronium impurity G and glycopyrronium impurity J) were separated with hRf values of 17, 34 and 69, respectively. Quantitative determination at 220 nm in the range of 0.3 - 10 and 0.2 - 4.0 μg/zone. The LOD and LOQ were 0.1, 0.3 and 0.05, 0.2 μg/zone for GLY and its related impurities, respectively. The recovery was 99.5 ± 1.4, 100.0 ± 1.3 and 99.6 ± 0.8 and R2 ≥ 0.9968 for GLY and its impurities, consecutively.

J. Chinese Trad. Patent Med. 41 (7), 1728-1731 (2019). Sarcandra glabra (Thunb.) Nakai is a component herbal TCM drug with anti-bacteria, anti-inflammation, and anti-tumor activity. For quality control, TLC on silica gel at 25 % relative humidity and 21 °C with (A) toluene - ethyl acetate - formic acid 9:4:1, (B) cyclohexane - ethyl acetate - formic acid 7:6:1, (C) cyclohexane - ethyl acetate - formic acid 4:5:1. Detection (A) at UV 366 nm, (B) by exposure to ammonia vapor for 10 min and evaluation at UV 366 nm. Identification and assessment by comparison of the fingerprints with standards isofraxidin and rosmarinic acid. The method was successfully used for the analysis of 13 batches of real life samples.

J. of Chromatogr. Sci. 57 (6), 552-559 (2019). Analysis of chlorpheniramine maleate (CM), phenylephrine (PE) and guaifenesin (GF) in their mixture and in presence of the GF related substance guaiacol (GL) and the cough syrup preservative sodium benzoate (NaB) by TLC on silica gel with ethyl acetate - methanol - toluene - ammonia 14:3:2:1. Quantitative determination by absorbance measurement at 270 nm. The method was suitable for the determination of CM, PE, and GF in pure powder and in combined cough syrup without interference from the excipients.

Planta Med. 84(16), 1174-1182 (2018). The fractionation and purification steps (column chromatography, including reverse-phase HPLC) of an ethanolic extract of Millettia pinnata (= Pongomia pinnata, Fabaceae) roots were monitored by TLC on silica gel with n-hexane – ethyl acetate mixtures 4:1 - 2:1. Detection at 254 and 336 nm, and by spraying with sulfuric vanillin reagent followed by heating. The process allowed the isolation of 2 flavanols (including pongaflavanol), 1 flavanol ether and 26 flavanones (including derrivanone, griffinones, isoderricines, isoglabrachromene, isolonchocarpin, liquiritigenin, maxima flavanone A, ovalichromene B, ovaliflavanones, pinostrobin, pongachin, pongamone C, ponganone III).