Validated high-performance thin-layer chromatography method for determination of trigonelline in herbal extract and pharmaceutical dosage form.

A new, simple, sensitive, selective, precise and robust high-performance thin-layer chromatographic (HPTLC) method for analysis of trigonelline was developed and validated for the determination of trigonelline in herbal extracts and in pharmaceutical dosage forms. Analysis of trigonelline was performed on TLC aluminium plates pre-coated with silica gel 60F-254 as the stationary phase. Linear ascending development was carried out in twin trough glass chamber saturated with mobile phase consisting of n-propanol-methanol-water (4:1:4, v/v/v) at room temperature (25+/-2 degrees C). Camag TLC scanner III was used for spectrodensitometric scanning and analysis in absorbance mode at 269 nm. The system was found to give compact spots for trigonelline (R(f) value of 0.46+/-0.02). The linear regression analysis data for the calibration plots showed good linear relationship with r2=0.9991+/-0.0002 in the concentration range 100-1200 ng spot(-1) with respect to peak area. According to the International Conference on Harmonization (ICH) guidelines the method was validated for precision, recovery, robustness and ruggedness. The limits of detection and quantification were determined. The trigonelline content of herbal extracts quantified and estimated from the formulation was found to be well within limits (+/-5% of the labeled content of the formulations). Statistical analysis of the data showed that the method is reproducible and selective for the estimation of trigonelline.