J Chrom Sci, bmad042 (2023). Standards (separated and mixed) were antazoline (ANT) and tetryzoline (TET) hydrochlorides. Samples were one commercial ophthalmic solution containing both molecules (unspiked and spiked), and aqueous humour of untreated rabbits as biological fluid, spiked with various concentrations of ANT and TET. TLC on silica gel with ethyl acetate – ethanol 1:1. Visualization under UV 254 nm. Densitometric absorbance measurement at 220 nm (20mm/s scanning speed). The hRF was 47 for TET and 71 for ANT. System suitability was verified by resolution, selectivity, capacity and absence of tailing. The method was validated for linearity range (0.2 – 18 µg/band), for precision, for reproducibility, for robustness, and for accuracy expressed as average recovery values (100 % overall mean) at different concentrations. The method was also found statistically equivalent (Student’s t-test and F-test) to the official corresponding titrimetric methods of the European Pharmacopoeia. Finally, environmental and health impacts of the methods were qualitatively and quantitatively assessed better as the other described methods, using analytical greenness (AGREE), green analytical procedure index (GAPI), national environmental method index (NEMI), and analytical eco-scale (scores based on solvents/reagents, energy consumption, occupational hazard and waste generation).

J. Planar Chromatogr. 35, 609-616 (2022). HPTLC of chlorogenic acid (1), caffeic acid (2), β-sitosterol (3) and lupeol (4) in the flowers and roots of Inula grandiflora on silica gel with toluene - ethyl - acetate - formic acid - methanol 30:30:8:3 for (1) and (2), and toluene - ethyl acetate - glacial acetic acid 145:45:1 for (3) and (4). Detection by spraying with Natural product reagent for (1) and (2) and  p- anisaldehyde - sulfuric acid reagent for (3) and (4). Quantitative determination by absorbance measurement at 366 nm for (1) and (2) and 525 nm for (3) and (4). The hRF values for (1) to (4) were 18, 82, 71 and 88, respectively. Linearity was between 125 and 625 ng/zone for (1) to (4). Intermediate precisions were below 2 % (n=9). LOD and LOQ were 32 and 97 ng/zone for (1), 39 and 110 ng/zone for (2), 47 and 124 ng/zone for (3) and 29 and 89 ng/zone for (4), respectively. Average recovery was 98.9 % for (1), 96.7 % for (2), 97.8 % for (3) and 98.8 % for (4).

J. Planar Chromatogr. 35, 549-570 (2022). Review of the analytical application of deep eutectic solvents (DESs) in different chromatographic technologies, including TLC. The paper included a comprehensive list of applications of DESs as mobile phase/mobile phase modifiers, for the analysis of alkaloids and flavonoids.

J. Planar Chromatogr. 35, 579-584 (2022). HPTLC of neohesperidin from Citrus aurantium peel extract on silica gel with ethyl acetate - methanol - water - formic acid 71:14:10:5. Quantitative determination by absorbance measurement at 254 nm. The hRF value for neohesperidin was 54. Linearity was between 1000 and 3000 ng/zone. Intermediate precisions were below 2 % (n=9). Recovery was between 99.6 and 101.8 %. 

J. Planar Chromatogr. 35, 593-602 (2022). HPTLC of lactucin (1) and lactucopicrin (2) in the whole herb of Cichorium glandulosum on silica gel with ether - ethyl acetate 1:5. Quantitative determination by absorbance measurement at 256 nm. The hRF values for (1) and (2) were 42 and 65, respectively. Linearity was between 498 and 2988 ng/zone for (1) and 499 and 2994 ng/zone for (2). Intermediate precisions were below 5 % (n=6). Average recovery was 100.0 % for (1) and 99.5 % for (2). 

J. Planar Chromatogr. 35, 627-633 (2022). HPTLC of bromfenac in ophthalmic solution on silica gel with toluene - ethyl acetate - glacial acetic acid 375:175:1. Quantitative determination by absorbance measurement at 274 nm. The hRF values for bromfenac was 28. Linearity was between 60 and 270 ng/zone. Intermediate precisions were below 2 % (n=3). The LOD and LOQ were 7 and 22 ng/zone, respectively. Average recovery was 100.7 %.

J. Planar Chromatogr. 35, 603-608 (2022). HPTLC of berberine (1) and ursolic acid (2) in an Ayurvedic formulation on silica gel with chloroform - acetone - formic acid 12:7:1. Quantitative determination by absorbance measurement at 330 nm. The hRF values for (1) and (2) were 46 and 68, respectively. Linearity was between 200 and 1000 ng/zone for (1) and 500 and 2500 ng/zone for (2). Intermediate precisions were below 2 % (n=9). The LOD and LOQ were 91 and 175 ng/zone for (1) and 153 and 465 ng/zone for (2), respectively. Recovery was in the range of 98 and 102 % for (1) and (2).

J. Chromatogr. A. 1683, 463522 (2022). HPTLC of powdered root sample of Saussurea costus on silica gel with n-hexane - toluene - tetrahydrofuran 10:1:2. Planar bioluminiscent cytotoxicity assay by dipping into concentrated PBS, followed by removal of excess liquid and adding of human embryonic kidney (HEK) 293T cells expressing ELuc, which uses D-luciferin as the substrate for light emission (cell suspension of 5000 cells/μL). To avoid drying out of the plate, two stripes of paper were added to the side of the chamber, which were wetted with 1.5 mL of bidistilled water. After incubation for 6 h, the HPTLC plate was completely dried under cold air, followed by dipping twice into the respective bioluminescent substrate solution for each cell type. Dose-dependent cytotoxicity activity was calculated for the bioluminescence signal reduction.