Abstract CP-31, IPC (2005). HPTLC of stigmasterol in leptadernia reticulata on silica gel with n-hexane - ethyl acetate 4:1. Quantitative determination by absorbance measurement at 525 nm after derivatization. Both hydrolyzed and unhydrolyzed samples (2N HCl) were analysed. Unhydrolyzed samples were found to contain a higher amount of stigmasterol. Linearity was in the range of 0.16-0.48 mg/mL. Several market samples were analysed by the proposed method.

Indian Drugs 42 (12), 805-807 (2005). HPTLC of alprazolam and sertraline in tablet dosage form on silica gel with toluene - ethyl acetate - methanol - acetic acid 90:30:20:3 without saturation. Quantitative determination by absorbance measurement at 217 nm. Accuracy, precision, and linearity were established. The linearity range was 20-100 ng for alprazolam and 100-500 ng for sertraline. Recovery rates were between 99.8-100.5 % for both drugs.

whole-plant powder by High-Performance Thin-layer Chromatography. J. Planar Chromatogr. 19, 68-72 (2006). HPTLC of oleanolic acid on silica gel with dichloromethane - toluene - acetone - methanol 30:40:15:3. Detection by spraying with Liebermann-Burchard reagent; quantification by densitometry at 529 nm. Detection and quantitation limits were 0.1 µg and 0.5 µg, respectively. Oleanolic acid response was linear over the range 1 to 9 µg. The validated HPTLC method can be used for routine quality-control analysis of Oldenlandia corymbosa L. whole-plant powder and for quantitative determination of oleanolic acid.

Abstract GP-55, IPC (2005). HPTLC of methanolic extracts of ambroxol and cetirizine combination tablets, on silica gel with methanol - ethyl acetate - toluene - ammonia 40:15:56:10 drops of ammonia. Quantitative determination by absorbance measurement at 231 nm. Rf values of cetirizine was 0.40 and of ambroxol 0.78, linearity range was 0.4-0.8 µg for cetirizine and 4-10 µg for ambroxol. Recovery was 99.3-100.4 % for both compounds. In comparison with a spectrophotometric method the HPTLC method had the advantage of higher throughput.

by automated multiple development. J. Planar Chromatogr. 19, 115-117 (2006). HPTLC of eight ginsenosides on silica gel after cleaning with isopropanol for 1 h with methanol - chloroform. Two gradient programs and two different values of increment in the development distance were compared. Visualization by spraying with A) Godin’s reagent (5% solution of sulfuric acid in ethanol), and B) 1% solution of vanillin in ethanol, followed by heating at 105°C for 10 min. Evaluation by scanning at 540 nm.

J. Planar Chromatogr. 19, 348-354 (2006). HPTLC of puerarin, daidzein, daidzin, and 3’-methoxypuerarin on silica gel, pre-washed with methanol, in an unsaturated twin-trough chamber with chloroform - methanol - ethyl acetate - water 16.2:18.8:52:3. Quantitative determination by absorbance measurement at 254 nm. The relative standard deviation of Rf values, retention times and peak area percentages all meet the national standards.

J. Food Comp. Anal. 19, 118 - 126 (2006). HPTLC of andrographolide (AP) and 14-deoxy-11,12-didehydroandrographolide (DIAP) in the aerial parts of Andrographis paniculata Nees on silica gel with chloroform – methanol 4:1 with chamber saturation for 2 h. Quantitative determination at 254 nm. Good resolution of AP and DIAP was obtained together with symmetrical and reproducible peaks at Rf 0.55 and 0.43, respectively. Linearity is between 10 and 2000 µg/mL; LOD is 3.0 and 3.6 µg/mL; mean recoveries are 97.7 % and 97.8 % and precision analysis shows an intra-assay variation between 0.89 - 0.99 % and an inter-assay variation between 0.86 - 0.98 %. HPTLC method leads to accurate results when compared to the HPLC method.

J. Sep. Sci. 26, 1359-1362 (2003). HPTLC of tramadol and chlorzoxazone (internal standard) on silica gel with ethyl acetate - methanol 7:1 and 1 drop of ammonia. Quantitative determination by absorbance measurement at 275 nm. Linearity of determination of levofloxacin is between 1.0 and 2.5 µg and its average percentage recovery is 104.6 %.