Quantification of glycyrrhizin in Glycyrrhiza glabra extract by validated HPTLC densitometry

Glycyrrhiza glabra Linn (Family-Fabaceae) is active as an anti-allergic, anti-inflammatory, spasmolytic, mild laxative, antistress, antidepressive, antiulcer, liver protective, estrogenic, emmenagogue, and antidiabetic substance, and is widely used in the Indian system of medicine. The major bioactive constituent is glycyrrhizin. A simple HPTLC method has been developed to control the quality of raw as well as finished glycyrrhiza using glycyrrhizin as the bioactive marker. The solvent system was optimized to chloroform-methanol-water (65 + 36 + 7.5, v/v/v). Extract and standard were dissolved in 70% methanol and applied on a precoated TLC plate. After development, the plate was scanned at 254 nm to create a chromatogram, then the quantity of glycyrrhizin was determined in the extract. The method was validated in terms of specificity, linearity, precision, LOD, and LOQ. Linearity range was found to be 0.96-4.80 microg per spot. The linearity relationship was described by the equation: Y = 612.706 + 1.091X (with r = 0.99904 and SD = 2.52%), where Y is the area under curve and X is the amount of glycyrrhizin (ng). The amount of glycyrrhizin found in the extract was 9.1%. Thus, the method provides a rapid and cost-effective quality measure for Glycyrrhiza glabra hydroalcoholic extract.