J. Planar Chromatogr. 23, 134-136 (2010). TLC of sertraline on silica gel (prewashed with methanol) with chloroform - ethyl acetate - triethylamine 25:15:1 in a twin-trough chamber previously saturated for 10 min at room temperature. Quantitative determination by absorbance measurement at 279 nm. The hRf for sertraline was 40. Intra-day precision and inter-day precision was 99.84 % RSD and 99.92 % RSD, respectively. A good linear relationship between response (peak area) and amount was obtained over the range 2.7-7.9 µg/band.

Densitometric analysis of flecainide in tablets. J. Planar Chromatogr. 23, 65-69 (2010). TLC of some antiarrhythmic compounds (disopyramide phosphate, verapamil hydrochloride, flecainide acetate, mexiletine hydrochloride, and tocainide hydrochloride) on RP8 and RP18 silica gel with organic-aqueous mobile phases containing citrate or acetate buffers at different pH in a horizontal chamber. The best separation of individual and mixed drug standards was achieved with tetrahydrofuran - citrate buffer (pH 4.45) 3:7. Flecainide acetate was identified and quantified by UV densitometry at 225 and 310 nm. Linear relationships were obtained between peak height or peak area and amount in the range 6.0 to 12.0 µg/spot, the correlation coefficient r was 0.990. Precision (RSD 1.1-5.9 %) and accuracy (96.2-103.6 %) were satisfactory.

Phytochem. Anal. 21, 174-179 (2010). HPTLC of tiliroside (1), methyl brevifolincarboxylate (2), and ellagic acid (3) in the aerial parts of Potentilla species on silica gel with toluene - ethyl formate - formic acid 6:4:1. Quantitative determination by absorbance measurement at 320 nm for (1), 287 nm for (2), and 280 nm for (3). The hRf values of (1), (2) and (3) were 9, 13, and 20, respectively. Linearity was between 50 and 500 ng/zone for (1), 50 and 520 ng/zone for (2), and 52 and 500 ng/zone for (3). The intra- and inter-day precisions (expressed in terms of CV %) were observed in the ranges 2.5-9.0 % and 2.4-11.1 %, respectively. LOD for (1) to (3) were 5, 10 and 34 ng/zone, respectively, while LOQ were 27, 17 and 44 ng/zone, respectively. The average recovery of (1), (2) and (3) was 101.1, 82.2 and 94.0 %, respectively.

Journal of Chemical and Pharmaceutical Research 2(4), 907-913 (2010). TLC on silica gel with dichloromethane - methanol 99:1. The hRf value of prasugrel was 58±3. Prasugrel was subjected to stress test conditions like acid, alkali, neutral hydrolysis, oxidation, dry heat, and photo degradation. The zones corresponding to degradation products were well resolved from the main drug. Densitometric evaluation in absorbance mode at 254 nm. Linearity was in the range of 300-1500 ng/band.

J Food Sci Technol 46(2), 114-117 (2009). A method for isolation and analysis of the artificial sweetener sucralose from the Indian sweet Burfi has been developed. For the isolation samples were suspended in water, treated with K3Fe(CN)6 solution and zinc sulfate, and filtrated. Semi-quantitative HPTLC analysis on amino layer with acetonitrile - water 4:1. The developed plate was heated at 190 °C for 20 min and spots were detected under UV 365 nm. Treating the plate with 5 % methanol CTMA increased the sensitivity (25 ng/zone). Quantitative HPTLC on silica gel with dichloromethane - methanol 4:1. Detection by spraying with 15 % methanolic sulfuric acid and heating at 100 °C for 10 min. The spot density was evaluated with Bio-rad fluorescence imaging software and confirmed by comparison with the standard. The method was linear in the range of 0.5-1.25 µg/band.

J. Sci. Res. 1(1), 121-127 (2009). An HPTLC method is described for qualitative and quantitative estimation of sinapic acid in Lepidium sativum (Brassicaceae). Methanolic extracts of the plant material were subjected to chromatographic separation on HPTLC silica gel with n-butanol - acetic acid - water 4:1:5. Derivatization with anisaldehyde sulfuric acid reagent, followed by heating at 110 °C for 10 min. Denstiometric quantification at 326 nm. Identification was confirmed by comparison of hRf-values of sample and standard.

Eurasian J. Anal Chem 4(2), 152-160 (2009). A stability indicating HPTLC method has been reported for estimation of aspirin and clopidogrel bisulphate in combined dosage form. HPTLC on silica gel with carbon tetrachloride - acetone 5:2. The hRf value of aspirin was 13 and of clopidogrel 78. Densitometric evaluation at 220 nm. Linearity was in the range of 200-600 ng/spot for aspirin and 300-600 ng/spot for clopidogrel. Degradation products (acid, base oxidative, dry heat, photodegradation) did not interfer with the analysis.

Analytical Chemistry - An Indian Journal 8(1), 82-86 (2009). An HPTLC method is reported for estimation of beta-sitosterol in flowers of Woodfordia fruticosa (Lythraceae) and its polyherbal formulation. HPTLC on silica gel with toluene - ethyl acetate - methanol - glacial acetic acid 80:10:5:3. Methanolic extracts of the sample were used for chromatographic separation. Derivatization with Liebermann-Burchard reagent, densitometric quantification at 366 nm. The linearity range was 100-700 ng/band. The flowers of the plant contained 0.18 µg/mg beta-sitosterol and the tablet herbal formulation contained 0.15 µg/mg.