Determination of bioactive marker glycyrrhizin in Glycyrrhiza glabra root and commercial formulation by validated HPTLC-densitometric method

Objective: To develop a simple sensitive high performance thin layer chromatography (HPTLC)densitometric method for quantification of glycyrrhizin in the Glycyrrhiza glabra root methanol extract and licorice root capsule methanol extract. Methods: Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with the green solvents ethyl acetate: glacial acetic acid: methanol: water in proportion of 6:2:1:0.5, v/v/ v/v as mobile phase. Scanning and quantification of developed plate was done densitometrically at 254 nm. The method was validated for detection and quantification limits, precision, recovery and robustness according to International Conference on Harmonization guidelines. Results: The system gave compact spot for glycyrrhizin (Rf=0.280依0.001). The regression curve of standard was found to be Y=4.213x+22.078. The limit of detection (15.7 ng per band), limit of quantification (47.1 ng per band), recovery (99.4%-99.8%) and precision (≤1.62% and ≤1.84%; intraday and interday) were satisfactory for glycyrrhizin. Linearity range for glycyrrhizin was 20200 ng (r 2 =0.996). The content of glycyrrhizin was estimated as 5.9% and 11.2% w/w in glycyrrhizin in the Glycyrrhiza glabra root methanol extract and licorice root capsule methanol extract, respectively. Conclusions: This estimation technique is very much useful for the estimation of glycyrrhizin present in various formulations as well as for quality control of crude drugs containing glycyrrhizin.