Rapid RP-HPLC method for the quantification of glabridin in crude drug and in polyherbal formulation

A simple, economic, selective, precise and robust method has been developed and validated for the analysis of glabridin in crude drugs and polyherbal formulations. Reversed-phase chromatography is performed on a C18 column with water and acetonitrile as mobile phase in gradient elution method at a flow rate of 1 mL/min. Detection is performed at 230 nm and a sharp peak is obtained for glabridin at a retention time of 14.9 ± 0.02 min. Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range of 1-500 µg/mL; the regression coefficient is 0.9992 and the linear regression equation is y = 26.683x - 142.17. The method is validated for accuracy, precision, reproducibility, robustness and detection and quantification limits, in accordance with International Conference on Harmonization guidelines. Statistical analysis proved that the method is precise, reproducible, selective and accurate for the analysis of glabridin. The proposed, developed and validated high-performance liquid chromatography method for the quantification of glabridin can be used for the quality control and standardization of licorice (Glycyrrhiza glabra Linn.) and different herbal formulations in which licorice is present as a constituent.