Abstract No. 9324, IHCB (2009). HPTLC of hesperidin in orange peel extract and formulation on silica gel with ethyl acetate - methanol - water 100:17:13. Quantitative determination by absorbance measurement at 287 nm. The method was linear in the range of 10-1000 ng/spot. Hesperidin was subjected to degradation studies (acid, alkali, hydrolysis, oxidation, and thermal stress) and was found susceptible to different stress condition. The method was suitable for determination of hesperidin and its degradation products in bulk drug as well as formulations.

J. Pharm. Biomed. Anal. 47, 795-801 (2008). HPTLC of sesamin and sesamoline (the major lignans in sesamum oil and its herbal formulations) on silica gel with benzene - methanol 50:1 with chamber saturation. Quantitative determination by absorbance measurement at 290 nm. The identity of sesamin and sesamoline was confirmed by UV-VIS spectra, NMR and MS of the compounds obtained by scraping off from the plate and elution. For fingerprint analysis derivatization with 5 % methanolic sulphuric acid was performed, followed by heating at 100 °C for 20 min and densitometry at 450 nm.

J. Planar Chromatogr. 23, 184-189 (2010). Multidimensional planar chromatography on monolayer or multiphase plates and modern fiber optical TLC densitometer scanners with DAD is especially useful for correct identification of components of difficult, complicated mixtures, e.g. pesticides in plant extracts (after preliminary clean-up and concentration by, e. g., solid-phase extraction). TLC of clofentezine [3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine] in Herba Thymi on silica gel in a horizontal chamber with tetrahydrofuran - n-heptane 3:7 in the first direction, then with ethyl acetate - n-heptane 1:4 in the second direction. Detection in the range of 200 to 600 nm with a TLC-DAD scanner. Also TLC of thyme herb extracts on silica gel and on RP18 plates with tetrahydrofuran - n-heptane 3:7 in the first direction and with methanol - water 7:3 in the second direction. LOD and LOQ were 0.23 and 0.70 µg/band, respectively, in TLC-DAD and 0.35 and 1.06 µg/mL, respectively, in HPLC-DAD. Average recoveries from the spiked plant material samples were 80.1 % and 100.5 % at 2.5 µg/g and 95.1 % at 5 µ/g measured at 202 nm.

Abstract No. C-231, 61st IPC (2009). An HPTLC method is reported for determination of 3-OH-androstane-(16,17-C) (6-methyl-2-1-hydroxy-isopropene-1-yl)-4,5,6 H-pyran, a phyto constituent of Eugenia jambolana. The compound was isolated by ethanolic extraction, identified by melting point, IR, and NMR, and used as marker. HPTLC on silica gel with toluene - ethyl acetate 17:3. Densitometric evaluation at 366 nm. The method was linear in the range of 1000-5000 ng/band. It can be used for routine quality control of Eugenia jambolana seeds and herbal formulation.

J. Planar Chromatogr. 23, 70-74 (2010). Descripton of a selective and simple HPTLC method for quantification of oenothein B on the basis of the free gallic acid and total gallic acid content after acid hydrolysis. HPTLC of gallic acid on silica gel with benzene - methanol - acetic acid 90:16:8 in a glass chamber previously saturated with the mobile phase vapor for 20 min. Quantitative determination by absorbance measurement at 570 nm after derivatization with 1 % ethanolic iron(III) chloride solution. Average recovery of the active ingredient was in the range 95.4-104.6 %. Linearity was in the range of 440-2200 ng/band. The correlation coefficient r was 0.9991, LOD/LOQ were120/360 ng/band; repeatability (RSD) was 3.0 % and intermediate precision 1.0 %; intraday precision (RSD, n = 6, 440-2200 ng/band) was 3.8 to 5.2 % and interday precision 4.3 to 5.7 %. Both, precision and accuracy, were within acceptable limits for routine drug analysis (</= 15 %).

Asian Journal of Chemistry 23(1), 469-470 (2011). Several herbal formulations were analyzed for gallic acid contents. Tablets were powdered, subjected to hydrolysis by refluxing with 10 % HCl, filtrated and extracted with chloroform. Acidic aqueous extracts were concentrated and the residue was taken up in methanol. TLC on silica gel with ethyl acetate - formic acid 85:11. Gallic acid was observed at an hRf value of 89. Densitometric quantification of gallic acid at 272 nm. The method was linear in the range of 100-3000 ng/band. The method was suitable for analysis of formulations without interference from excipients. Gallic acid contents of different tablet samples varied from 0.06-0.15 % w/w.

International Journal of ChemTech Research 1(4), 1129-1135 (2009) The marker compound was first isolated by column chromatography over silica gel by elution with toluene - ethyl acetate 17:3. TLC of ethanolic extracts of Syzgium cumini seed on silica gel with toluene - ethyl acetate 17:3. The hRf value of the marker compound was 50. Densitometric evaluation in fluorescence mode at 366 nm. The method was linear in the range of 1-5 µg/band. The extract of the powdered sample contained 7.4 % of the marker compound.

Journal of Natural Remedies 10(2), 170-174 (2010). The powdered plant material was defatted, extracted with methanol, concentrated and successively extracted with ethyl acetate and n-butanol. The resulting fractions were concentrated and subjected to chromatographic fingerprint analysis of the phytoconstituents, i.e. alkaloids, saponins, tannins, flavonoids, anthraquinones and sterols. TLC on silica gel with n-butanol - acetic acid - water 4:1:5 for the ethyl acetate fraction and with chloroform - methanol 9:1 for the n-butanol fraction. Densitometric evaluation at 254 nm and 366 nm for the n-butanol fraction and at 290 nm for the ethyl acetate fraction. Derivatization with vanillin-sulfuric acid reagent for the n-butanol fraction and with AlCl3 reagent for the ethyl acetate-fraction, evaluation at 600 nm. The n-butanol fraction contained sterols and saponins, the ethyl acetate fraction flavonoids.