Stability-Indicating HPTLC Determination of Capsaicin in the Bulk Drug

A simple, selective, precise, and stability-indicating high-performance thin-layer chromatographic (HPTLC)method for analysis of capsaicin in the bulk drug has been developed and validated. The method employs aluminum TLC plates precoated with silica gel 60F(254)as stationary phase. The mobile phase was toluene-ethyl acetate 6:4 (v/v). A compact spot was obtained for capsaicin (R-F 0.38 +/- 0.02). Densitometric analysis of capsaicin was performed in absorbance mode at 280 nm. Regression analysis of calibration data revealed a good linear relationship (r(2)> 0.9936)for peak-area data in the concentration range 100-1000 ng per band. The method was validated for accuracy, precision, linearity, limit of detection, limit of quantitation, and robustness. The limits of detection and quantitation were 20 and 60 ng per band, respectively. Capsaicin was subjected to acidic and alkaline hydrolysis, oxidation, and thermal degradation. The drug undergoes degradation under acidic, basic, and oxidizing conditions and at elevated temperatures. Statistical analysis proved the method enables precise, selective, and accurate analysis of capsaicin. The method can be used for identification and quantitative analysis of capsaicin in the bulk drug.