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).

Planta Med. 84(12-13), 941-946 (2018). The activity-guided fractionation and purification steps (column chromatography and liquid-liquid partitions) of a hydromethanolic extract of Alchemilla vulgaris aerial parts (Rosaceae) were monitored by TLC on silica gel with ethyl acetate – acetic acid – formic acid – water 100:11:11:27. Detection at 254 and 336 nm, and by spraying with anisaldehyde reagent followed by heating. A flavonoid (quercetin-glucuronide) was isolated through this process.

Planta Medica 84(12-13), 902-912 (2018). A dichloromethane extract of Athrixia phyllicoides aerial parts (Asteraceae) was eluted on a silica gel column with different mixtures of ethyl acetate and hexane or methanol. This fractionation was monitored on TLC silica gel layers, using the combinations of the same solvents as mobile phases. Detection by derivatization with Natural Product Reagent and PEG, and visualization at UV 254 nm. This allowed the grouping of the fractions into 13 profiles and the isolation of three hydroxy-methoxyflavones and a coumarate.

Planta Medica 84(11), 813-819 (2018). Fluorinated analogues of epigallocatechin-gallate were purified after synthesis by extraction with ethyl acetate from the synthesis mixtures, followed by column chromatography or (for two pairs of isomers) by preparative TLC. This isolation (as well as monitoring of column elution for the other compounds) was performed by TLC on silica gel with mixtures of n-hexane and (less) ethyl acetate in several concentrations, allowing the separation of diastereoisomers (RF values and yields are given). No derivatisation, visualisation because of fluorescing agent in the layers. Structures were identified by NMR and HR-MS, but apart from the TLC.