Simultaneous Determination and Stability Assessment of Metformin and Sitagliptin in Pharmaceutical Form by High Performance Liquid Chromatography

Abstract

A simple, rapid and highly selective chromatographic procedure is developed for simultaneous quantification of Metformin and Sitagliptinin tablet formulation. The active ingredients are separated using dihydrogen phosphate buffer (pH 6.00)/acetonitrile mobile phase, flow rate 1.0 mL.min-1, and with DAD detection at 218 nm. The stability and assay separation process are accomplished in 9.0 min with high resolution. The method is precise and accurate. A wide dynamic ranges (1.0-15.0) and (2.0-150.0) mg/L for Metformin and Sitagliptin, respectively, is employed. Both drugs are quantified down to 0.1 and 1.0 mg/L for Metformin and Sitagliptin, respectively, which indicates the high sensitivity of the procedure. Finally, the stability-indicating capability of the procedure is accomplished for tablet formulation (50 mg Metformin and 500 Sitagliptin), and the results indicated that Metformin is unstable to UV and H2O2 with degradation higher than 30.0%. Furthermore, Sitagliptin is unstable at acidic, basic, and oxidation environments