In response to growing environmental concerns in analytical chemistry, this study developed and validated a robust, efficient HPLC method for simultaneous estimation of Dolutegravir (DLV) and Rilpivirine (RLV) in bulk and tablet formulations. Optimization using Central Composite Design (CCD) within a Design of Experiments (DoE) framework established critical chromatographic parameters on a Phenomenex C18 column (250 x 4.6 mm, 5 μm) with PDA detection at 272 nm. The optimized mobile phase comprised acetonitrile and phosphate buffer (66:34 % v/v) at pH 3.1, with a flow rate of 0.9 mL/min. The method showed retention times of 2.75 min (DLV) and 3.44 min (RLV), resolution > 2.0, and capacity factors (K′) within standard range, ensuring peak separation. Forced degradation studies demonstrated specificity, with drug degradation ranging from 3.25% (photolytic) to 23.9% (alkali), confirming the method's stability-indicating capability. The quadratic and interaction models accounted for over 90% of response variability (R² > 0.90), revealing significant effects of pH, flow rate, and organic phase composition. Validation per ICH Q2(R2) guidelines showed accuracy between 98–102%, precision (%RSD) below 2%, and high robustness. This approach bridges gaps in existing literature by integrating comprehensive degradation profiling, statistical optimization, and design space modeling with risk assessment.
Shelke et al. (Tue,) studied this question.