Background In June 2021, the Central Drug Standards Control Organization approved a fixed-dose combination tablet containing remogliflozin etabonate (100 mg) and teneligliptin (10 mg) to manage type II diabetes. Objective This study aims to develop a stability-indicating RP-HPLC method for quantifying remogliflozin etabonate and teneligliptin in tablet formulations via analytical quality by design (AQbD) principles. Methods Risk assessment, Plackett–Burman design, and central composite design were employed to understand the impact of independent variables on critical analytical attributes. The stationary phase was a HyperClone BDS C18 column, and the mobile phase consisted of acetonitrile and phosphate buffer (20 mM, pH 5) at a 45:55% (v/v) ratio. Results The method, validated per ICH Q2 (R1), resulted in retention times of 3.395 and 12.308 min for teneligliptin and remogliflozin etabonate, respectively. Forced degradation studies confirmed robustness, with clear peak separation and no interference from degradation products. The AGREE score of 0.65 supports its green applicability for tablet analysis in quality control. Conclusion The AQbD-assisted RP-HPLC method developed in this study offers environmental friendliness, efficient separation with well-defined peaks, and simple mobile phase combination.