Liquid Chromatography Technique for Simultaneous Estimation of Metformin and Vildagliptin. Application to Pharmacokinetic in Diabetic Rabbits

Metformin hydrochloride is biguanide drug and vildagliptin is dipeptidyl peptidase 4 (DPP4) inhibitor which are orally administered as a primary medication to cure Type 2 Diabetes mellitus (T2DM), a widely spread chronic disease. Studies of vildagliptin have shown prominent improvements in glycemic control as an add-on to metformin. This research work is focused to acquire and authenticate a precise method to determine metformin and vildagliptin in rabbit plasma and to implement it for pharmacokinetic studies in diabetic rabbits. The method provides recoveries between the range of 100.13-100.29%, successfully determined the MTF and VLD concentration in rabbit plasma after oral examination of these drugs. The AUC(0-24), AUC(0-infinity) of metformin of reference versus test formulation were 14504.5, 14952.1 ng. h/mL versus 14779.6, 16046.17 ng.h/mL for MTF and 4372.4,3588.6 ng.h/mL versus 3317.8,3433.7 ng.h/mL for VLD and MRT, Vd and CL of reference versus test formulation were 5.7, 568.5 and 68.9 versus 5.1, 564.3, and 67.7 for MTF while 5.67, 42.33 and 14.4 versus 5.5, 46.7, and 15.1 for VLD, which showed no significance difference between pharmacokinetics parameters of both test and reference formulations.