Development and Validation of Glimepiride and Metformin in Human Plasma by HPLC: An application study

Abstract

A simple and cost effective RP-HPLC method is developed for simultaneous estimation of glimepiride (GLIM) and metformin (MET) at tablet dosage form using C-18 column (4.6 x 250mm, 5?, 100 A?) with a mobile phase composed ofmethanol: water (90:10% v/v) buffered with ortho phosphoric acid at a flow rate of1.0 mL/min (UV detection at 231 nm). The retention time of both drugs (GLIM and MET) are observed as 4.286 and 2.262 respectively. Human plasma spiking studies of both the API and the formulation at the concentration of (0.2g/mL - 1g/mL) for glimepiride and metformin (1g/mL - 5g/mL) expresses the standard correlation coefficients of 0.9998 and 0.9999 respectively for API and 0.9917 and 0.99 respectively for the tablet dosage form. The mean (%) recoveries of glimepiride and metformin are 99.98 and 99.9% respectively. The % RSD below 0.5 shows the high precision of the proposed method. Assay studies revealed that 98.05% of purity is observed for glimepiride and 99.69 for metformin in a tablet dosage form. Human plasma spiking studies revealed that a minimal quantum of glimepiride had been bound with the plasma proteins compare to metformin in the tablet dosage form. The method was validated as per the ICH guidelines.