J. Planar Chromatogr. 36, 191-200 (2023). HPTLC of gatifloxacin on silica gel impregnated with 20 mM levocetirizine and levosalbutamol as chiral selector at pH 5, with acetonitrile - methanol - triethanolamine 1:3:1. Detection by exposure to iodine vapor. The hRF values for (RS)-gatifloxacin were 46 and 86, respectively. The LOD for the enantiomer of gatifloxacin was 4.2 μg/zone and 4.9 μg/zone, respectively.

Chinese J. Pharm. Research 42 (2), 98-104 (2023). Ganoderma lucidum is the dry fruiting body of fungus, a medicinal plant, having the effect of relieving asthma and relieving nerves. Ganoderma lucidum is widely distributed in China and mainly concentrated in Zhejiang, Anhui, Shandong, Jilin, and Fujian. In this study, the HPTLC method for quality detection and origin traceability was established towards the medicinal material produced in Fujian and other areas. HPTLC of the ethanol extracts of the sample materials on silica gel with chloroform – acetonitrile – methanol – formic acid 130:15:2:2, three times to distances of 3 cm, 6 cm, 8 cm. Detection by spraying with 3 % sulfuric acid in ethyl acetate and heating at 105°C until the bands are clearly visualized, evaluation at UV 366 nm. The bands on the thin layer chromatogram were identified by fingerprint comparison using standard samples, and cluster analysis for the data of samples from different producing areas was performed using digital characterization. As results, the HPTLC analysis detected 17 distinct bands and among them, 11 components were identified, e.g. ganoderenic acid C (hRf 0.31), ganoderic acid C2 (hRf 33), ganoderic acid l (hRf 35), ganoderic acid G (hRf 41), ganoderic acid A (hRf 44), ganoderic acid B (hRf 46), ganolactone B (hRf 53), 3β,7β,15β-trihydroxy-11,15-dihydroxy-lanostane-8-alkene-24→20 lactone (hRf 56), ganoderenic acid D (hRf 61), ganoderic acid D (hRf 63) and 20 (21)-dehydrolucidenic acid A (hRf 65). A total of 10 HPTLC bands were identified in Fujian Ganoderma lucidum, among which ganoderic acid C2, ganoderic acid D and two unknown component bands (hRf 14 and 17) were unique and could be used as markers of Fujian Ganoderma lucidum. Thus samples of Fujian Ganoderma lucidum can be differentiated from those of other areas, when the Euclidean distance is 25 in Euclidean cluster analysis.

J Chromatogr Sci, 61 (3), 269-278 (2023). Development of a method for identification, quantification and stability study of linalool in Homalomena aromatica Schott, a herb with anti-rheumatism, nourishing and strengthening effects, and for the treatment of stomach disease. HPTLC hyphenated with MS for linalool on silica gel with toluene - ethyl acetate 19:1. Detection  with p-anisaldehyde reagent. The hRf of linalool is 35, identification of linalool at m/z 137, (M + H)+ by using MS technique. Study of the stability of linalool by investigating the effect of acid, base, UV, sunlight, thermal stress and H2O2 on it, the highest effect was observed with acidic pH with a 65 % degradation. The content of linalool was 58 % in the volatile oil of H. aromatica.

J  Chromatogr Sci, 61(3), 225-233 (2023). Development of a method for analyzing rosmarinic acid (RA), caffeic acid (CA), ursolic acid (UA) and oleanolic acid (OA) in different organs of Salvia deserta Schang qualitatively and quantitatively by HPTLC (A) for RA and CA, on silica gel with chloroform – methanol - formic acid 20:4:1, quantitative absorption measurement at 330 nm; (B) for UA and OA, on silica gel F254 with cyclohexane - ethyl acetate - methanol 20:4:1, quantitative absorption measurement at 550 nm. The linearity ranges were 0.13-0.44, 0.01-0.09, 0.50-2.50 and 0.50-2.50 mg for RA, CA, UA and OA, respectively, with corresponding correlation coefficients of 0.9938, 0.9981, 0.9971 and 0.9969, respectively. The recovery rates were between 95 % and 105 %. LOD and LOQ were 50, 58, 25, 33 and 160, 191, 80, 106 ng for RA, CA, UA and OA, respectively.

J. Chrom Sci., 60 (9), 859-870 (2022). Development of an HPTLC method for the simultaneous estimation of carvedilol (CAR) and ivabradine (IVA). The combination of CAR and IVA is used for reduction of the heart rate and for achieving better exercise capacity in patients with chronic heart failure. The design approach based on the principles of analytical failure modes critical effect analysis (AFMCEA) and design of experiments (DoE) as per the upcoming ICH Q14 guideline were applied. Starting the AFMCEA by the identification of potential analytical failure modes followed by their critical effect analysis by a DoE-based screening design. Optimization of the high-risk failure modes by DoE-based response surface methodology. Framing the method operable design ranges and control strategy for optimized chromatography conditions. Validation of the HPTLC method as per ICH Q2 (R1) guideline. Application for the assay of facility design criteria (FDC) of CAR and IVA, giving the results in compliance with the labeled claim, and proven the developed method able to be used as an alternative to the published RP-HPLC method for quality control of FDC of CAR and IVA in the pharmaceutical industry.

J. Planar Chromatogr. 36, 21-30 (2023). HPTLC of tinidazole (1) and ciprofloxacin (2) in pure form, tablet dosage form and human plasma on silica gel with acetone - ethanol - 2 % watery sodium dodecyl sulfate 3:4:2. Quantitative determination by absorbance measurement at 310 nm. The hRF values for (1) and (2) were 22 and 42, respectively. Linearity was in the range of 25-1000 ng/zone for (1) and 80-1000 ng/zone for (2). Intermediate precisions were below 2 % (n=3). LOD and LOQ were 7 and 20 ng/zone for (1) and 25 and 75 ng/zone for (2). Average recovery was 99.9 % for (1) and 99.7 % for (2).

J. Sep. Sci. 2300332 (2023). HPTLC of cilnidipine on silica gel with n-heptane - ethyl acetate - triethyl amine 6:14:1. Quantitative determination by absorbance measurement at 254 nm. The hRF value for cilnidipine was 42. Linearity was in the range of 100-500 ng/zone. Intermediate precisions were below 2 % (n=3). LOD and LOQ were 24 and 72 ng/zone, respectively. Recovery was between 98 and 102 %.

Front. Nutr. 9, 887992 (2022). HPTLC of 13 mogrosides, 1 flavonoid, and 3 sugars in monk fruit products on silica gel with n-butanol - water - ethanol - acetic acid 70:10:10:2. Detection by spraying with 10 % sulfuric acid in ethanol solution, followed by heating at 105 °C for 10 min. Orthogonal partial least square-discriminant analysis (OPLS-DA) was subsequently conducted allowing the identification mogroside V, 11-oxo-mogroside V, isomogroside V, mogroside IV and sucrose to be the characteristic compounds to distinguish the two types of monk fruits.