Development and validation of RP-HPLC method for simultaneous estimation of picroside I, plumbagin, and Z-guggulsterone in tablet formulation

The aim of the present work was to develop and validate a reversed-phase high-performance liquid chromatography method for the simultaneous estimation of picroside I, plumbagin, and Z-guggulsterone in a polyherbal formulation containing Picrorhiza kurroa, Plumbago zeylanica, and Commiphora wightii extracts. The analysis was performed on a C18 column using the mobile phase consisting of solvent A (acetonitrile) and solvent B (0.1% orthophosphoric acid in water) with the following gradient: 0-12 min, 25% A; 12-17 min, 25-80% A; 17-32 min, 80% A; and 32-37 min, 80-25% A at a flow rate of 1 ml/min. Ultraviolet detection was at 255 nm. The method was validated for accuracy, precision, linearity, specificity, and sensitivity as per the norms of the International Conference on Harmonization. From the validation study, it was found that the method is specific, accurate, precise, reliable, and reproducible. Good linear correlation coefficients (r(2)>0.900) were obtained for calibration plots in the ranges tested. Limits of detection were 2.700, 0.090 and 0.099 μg/ml and limits of quantification were 9.003, 0.310, and 0.330 μg/ml for picroside I, plumbagin, and Z-guggulsterone, respectively. Intra and interday relative standard deviation (RSD) of retention times and peak areas was less than 3.0%. Recovery was found to be 100.21% for picroside I, 102.5% for plumbagin, and 103.84% for Z-guggulsterone. The established method was appropriate and the three markers were well resolved, enabling efficient quantitative analysis of picroside I, plumbagin and Z-guggulsterone. The method is a rapid and cost-effective quality control tool for routine quantitative analysis of picroside I, plumbagin, and Z-guggulsterone in tablet dosage form.