This research paper focuses on the development and validation of a robust and efficient RP-HPLC method for the simultaneous estimation of drug combinations in marketed formulations. The study is divided into two parts, addressing the simultaneous estimation of Metformin & Sitagliptin, and Metformin & Saxagliptin, respectively. The analytical parameters evaluated for method validation include system suitability, specificity, linearity, accuracy, limit of quantification (LOQ), limit of detection (LOD).