Development and validation of a TLC-densitometric method for the quantitation of Glycyrrhizinic Acid in herbal formulation

A simple, sensitive, and specific thin-layer chromatography densitometric method has been developed for the quantitation of glycyrrhizinic acid. The poly herbal formulations containing Mulethi were widely used for expectorant and carminative in ancient times. The present paper deals with the development of a densitometric method for fingerprint of Mulethi mainly using glycyrrhizinic acid in the form of densitogram following charring of the chromatographic as internal standard that could be useful for marker-based quality assurance of the poly herbal products containing Glycyrrhiza glabra Linn. The method involves densitometric evaluation of glycyrrhizinic acid after resolving it by high-performance TLC on silica gel plate with chloroform: methanol: water (6.5:3.5:1) as the mobile phase. The method is validated for precision (interday and intraday), repeatability, and accuracy. The relationship between the concentration of standard solutions and the peak response is linear within the concentration range of 100 to 600 ng/spot for glycyrrhizinic acid. Accuracy of the method is checked by recovery study conducted at three different levels and the average percentage recovery was found to be 99.71% for glycyrrhizinic acid. The proposed HPTLC method for the quantitation of glycyrrhizinic acid was found to be simple, precise, specific, sensitive, and accurate, and it can be used for routine quality control of raw material of G. glabra Linn. It also can be applied in quantitating any of these marker compounds in other formulations.