Talanta, 80 (3), 1045-1051 (2010). Review on chromatographic methods for synthetic food dyes, including the following techniques: TLC, HPTLC, traditional column chromatography, HPLC, ion-pair chromatography, RP HPLC, and high performance ion chromatography, demonstrated by using examples in different conditions for each technique.

J Young Pharm 1(5), 82-85 (2010). HPTLC of ascorbic acid in different varieties of amla fruit (collected from different geographical regions) on silica gel with ethanol - acetic acid 19:1. The hRf value of ascorbic acid was 76. Densitometric evaluation at 254 nm. The method was linear in the range of 1-5 µg/band. Bigger fruits were found to contain higher concentrations of ascorbic acid. The reported method was applied for estimation of ascorbic acid in crude drug as well as in herbal and pharmaceutical dosage form with reproducible results.

Eurasian J. Anal. Chem 5(1), 95-103 (2010). An HPTLC method is reported for quantification of glycyrrhetinic acid and apigenin in Glycyrrhiza glabra. Methanolic and acidic-methanolic extracts are subjected to chromatographic separation on silica gel with ethyl acetate - ethanol - water - 25 % ammonia 63:20:4:1. The method was linear in the range of 160-960 ng/band for glycyrrhetinic acid and 32-96 ng/band for apigenin. Glycyrrhiza glabra was found to contain 0.65 % of glycyrrhetinic acid and 0.0004 % of apigenin.

Analytical Chemistry - An Indian Journal 8(4), 608-612 (2009). An HPTLC method is reported for estimation of lupeol and beta-sitosterol from the whole plant of Vernonia cinerea (Acanthaceae). Methanolic extracts of the plant were subjected to chromatographic analysis on silica gel with toluene - methanol 220:3. Derivatization with Liebermann-Burchard reagent. Densitometric evaluation at 366 nm. The plant was found to contain 0.49 mg/g and 1.4 mg/g of lupeol and beta-sitosterol respectively. The method was suitable for quality control of herbal raw material.

E-Journal of Chemistry 7(2), 341-348 (2010). HPTLC of nebivolol hydrochloride and hydrochlorothiazide on silica gel with ethyl acetate - methanol - 25 % ammonia 17:2:1 with chamber saturation. The hRf value of hydrochlorothiazide was 21 and of nebivolol 41. Densitometric evaluation at 285 nm. The method was linear in the range of 200-1000 ng/band for nebivolol and 500-2500 ng/band for hydrochlorothiazide. The recovery was 98.9-102.4 %. Comparison of the HPTLC method with a RP-HPLC method and a UV spectroscopic method gave comparable results. The HPTLC method is suitable for routine quality control.

Journal of Pharmacy Research 3(2), 332-334 (2010). HPTLC on silica gel with methylene chloride - methanol - ammonia 17:2:1. The hRf value of amlodipine was 19 and of nebivolol 41. Densitometric evaluation at 285 nm. The method was linear in the range of 100-500 ng/band for both compounds. The average recovery was 99.9-102.1 for both compounds and there was no interference with additives present in tablet dosage forms.

Indian J. Pharma. Educ. Res. 44(4), 341-344 (2010). HPTLC of silica gel with toluene - ethyl acetate - methanol - formic acid 5:16:21. The hRf value was 51. Densitometric evaluation at 220 nm. The method was linear in the range of 300-1800 ng/band. The sample was subjected to different stress conditions (acid, base, oxidative, thermal, and photolytic). Degradation products were well separated from trandolapril, therefore the method can be used for stability studies.

J. of Chromatogr. A 1218 (19), 2648-2660 (2011). Review on the kinetic performance of stabilized particle layers, particle membranes, and thin films for TLC. Forced flow and pressurized planar electrochromatography is best suited to overcome the limited performance achieved by capillary flow for stabilized particle layers. For conventional and high performance plates band broadening is dominated by molecular diffusion at low mobile phase velocities typical of capillary flow systems and by mass transfer with a significant contribution from flow anisotropy at higher flow rates typical of forced flow systems. There are few possible changes to the structure of stabilized particle layers that would significantly improve their performance for capillary flow systems while for forced flow a number of avenues for further study. New media for ultra TLC shows possibilities for miniaturized high performance systems but the realization of their true performance requires improvements in instrumentation for sample application and detection.