QBD APPROACH TO HPLC MTHOD DEVELOPMENT AND VALIDATION OF THE SIMULTANEOUS ESTIMATION OF SULBACTUM AND DURLOBACTUM IN PHARMACEUTICAL DOSAGE FORM

A Quality by Design (QbD)-based RP-HPLC method was developed and validated for the simultaneous estimation of Sulbactam (SUB) and Durlobactam (DUB) in pharmaceutical dosage forms. Critical method parameters were optimized using a Box–Behnken experimental design by evaluating the effects of flow rate, buffer pH, and mobile phase composition on chromatographic performance. Separation was achieved on a Hypersil Gold C18 column (3.0 × 150 mm, 3 μm) using Methanol: 0.1% Formic Acid (65:35, v/v) as the mobile phase at a flow rate of 1.0 mL/min, with UV detection at 220 nm. The retention times of SUB and DUB were found to be 2.162 min and 3.441 min, respectively. The method exhibited excellent linearity over the concentration range of 10–50 μg/mL with correlation coefficients (R²) of 0.999 for both analytes. The assay result was 101.2%, while precision studies showed %RSD values below 2%. Recovery ranged from 97.6% to 98.9%, confirming the accuracy of the method. The developed method was validated according to ICH guidelines and demonstrated satisfactory robustness, sensitivity, and reproducibility. Therefore, the proposed AQbD-based RP-HPLC method is suitable for routine quality control analysis of Sulbactam and Durlobactam in pharmaceutical formulations.