Development and validation of HPTLC method for simultaneous estimation and stability indicating study of metformin HCl and linagliptin in pharmaceutical formulation A.Rajasekaran*, R. Kavitha, R. Arivukkarasu Department of Pharmaceutical Analysis, KMCH College of Pharmacy, Coimbatore-35, India

A simple, precise, rapid, selective, and economic high-performance thin layer chromatographic method has been established for simultaneous estimation of Metformin Hydrochloride and Linagliptin in formulation. The chromatographic separation was performed on precoated silica gel 60 GF254 plates with acetone-methanoltoluene-formic acid 4:3:2:1 (v/v/v/v) as mobile phase. The plates were developed to a distance of 8 cm at ambient temperature. The developed plates were scanned and quantified at their single wave length of 259 nm. Experimental conditions such as band size, chamber saturation time, migration of solvent front, slit width, etc. was critically studied and the optimum conditions were selected. The drugs were satisfactorily resolved with Rf 0.61 and 0.82 for metformin hydrochloride and linagliptin respectively. The method was validated for linearity, accuracy, precision, and specificity. The calibration plot was linear between 400-2000 (ng/spot) and 20-100 (ng/spot) for metformin hydrochloride and linagliptin respectively. The limits of detection and quantification for metformin hydrochloride and linagliptin 20 (ng/spot) and 10 (ng/spot) respectively.