Objective: The objective of the proposed method was to develop a simple, fast, sensitive, and validated high-performance liquid chromatography (HPLC) method for the simultaneous estimation of metformin and vildagliptin in tablets and human plasma. Materials and Methods: The chromatographic separation was accomplished with a fast monolithic column using a mixture of sodium dihydrogen phosphate and sodium dodecyl sulfate and acetonitrile at pH 4.5 as the mobile phase. In addition, newly developed method was validated as indicated by International Conference on Harmonization guidelines. Results: The method showed good correlation coefficients (r ≥ 0.997) in the range of 0.05-20 μg/mL and 0.1-40 μg/mL for metformin and vildagliptin, respectively. The accuracy and intraday and interday precision results were within the acceptable range for both analytes. The mean extraction recoveries of metformin and vildagliptin from human plasma were 97.51% and 97.18%, respectively. Conclusion: The simple, rapid, sensitive, robust and validated analytical method developed was used for simultaneous estimation of metformin and vildagliptin in formulation and in patient plasma.
Key words: Formulation, high-performance liquid chromatography, metformin, plasma, simultaneous determination, validation, vildagliptin.