J. AOAC Int. 87, 573- 578 (2004). TLC of propanolol/reagent azo adduct (with diazotized 4-amino-3,5-dinitrobenzoic acid) on silica gel with ethyl acetate - methanol 9:1, chloroform - methanol 4:1, methanol - ammonia 200:3 (plate was impregnated with 0.1 M methanolic KOH before spotting). Evaluation under UV light at 254 nm.

IPC 56th 2004, Abstract No. G-28. Neem Oil obtained from the seed kernels of Azardirachla indica (Meliaceae) is a fixed oil known as oil of Margosa. An HPTLC method is reported for the analysis of Neem oil as a bulk drug and formulations containing oil. TLC of neem oil extracted with chloroform, on silica gel with chloroform - n-hexane - methanol 18:2:1. Quantitative determination by scanning at 254 nm. The linearity range was 100 – 500 mg/mL. Formulations were found to contain 0.35 g/g of Neem Oil.

IPC 56th 2004, Abstract No. GP-26. HPTLC of triphala, an ayurvedic formulation containing about 3.60 % of total phenolics. Separation of alcoholic triphala extracts on silica gel with n-hexane - ethyl acetate 2:1. Rf value of the main spot gallic acid was 0.04 in triphala and its formulation. The method was found to be very specific for gallic acid having a linearity range of 0.2 - 1.6 mg/mL. Several formulations analyzed by HPTLC contained 5.2 - 7.6 % of gallic acid. The reported method is suitable for estimation of gallic acid in raw material and formulations.

Abstract G-28, IPC (2005). HPTLC of rosuvastatin on silica gel with chloroform - methanol - toluene 3:1:1. Quantitative determination by absorbance measurement. The hRf value of rosuvastatin was 53, recovery rate was between 98-102 %, LOD was 8 ng/spot and LOQ 26 ng/spot.

Abstract G-19, IPC (2005). HPTLC for estimation of corticosterone in rat plasma on silica gel with chloroform - methanol - water 9:10:1. Quantitative determination by absorbance measurement at 245 nm. Betamethasone was employed as internal standard. The extraction of plasma with ethyl acetate gave an average recovery of >85 %. The linearity was within the range of 30-300 ng/mL with LOQ being 30 ng. The method was found to be rugged and robust.

J. Pharm. Biomed. Anal. 39, 801-804 (2005). HPTLC on silica gel with chloroform - methanol 9:1. Quantitative determination by absorbance measurement at 265 nm. The hRf values of stavudine (SV), lamivudine (LV) and nevirapine (NV) were 25, 67 and 87 respectively. The method was linear within the range of 0.01-0.06 mg/mL, 0.05-0.30 mg/mL and 0.06-0.40 mg/mL for SV, LV, and NV respectively, recovery rates were between 98.2 and 99.9 %. The HPTLC method was compared with the UV and HPLC methods. Accuracy, precision and ruggedness of the method were established.

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.

L. Planar Chromatogr. 19, 135-138 (2006). HPTLC of nitrendipine on silica gel with n-hexane - ethyl acetate - acetone 6:3:2 in a horizontal chamber. Visualization under UV light. Densitometry was performed in absorbance mode at 335 nm. The calibration plot was constructed in the range 0.025 to 0.150 µg/µL (corresponding to 0.5-3.0 µg/spot) with good correlation (r2> 0.990). The method is also characterized by good precision and accuracy.