QUALITY BY DESIGN-DRIVEN REVERSED PHASE-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD DEVELOPMENT, OPTIMIZATION, AND VALIDATION FOR SIMULTANEOUS ESTIMATION OF SOFOSBUVIR AND VELPATASVIR IN BULK AND TABLET DOSAGE FORM

Abstract

Objective: To create and validate a stability-indicating Reversed Phase-High Performance Liquid Chromatography(RP-HPLC) technique based on Quality by Design (QbD) for the simultaneous measurement of Sofosbuvir (SOF) and Velpatasvir (VEL) in pharmaceutical dosage forms and bulk. Methods: A QbD approach using Central Composite Design (CCD) was applied to evaluate the effect of critical method parameters, including mobile phase composition and flow rate, on analytical performance. Chromatographic separation was achieved using a Denali C18 column (150 × 4.6 mm, 5 µm) with phosphate buffer (pH 4.5) and acetonitrile (57.74: 42.26 % v/v) at a flow rate of 0.9833 ml/min. Detection was performed at 268 nm with a run time of 6 minutes. The method was validated according to the International Council of Harmonisation guidelines (ICH) Q2(R2). Results: The SOF and VEL retention times were 2.20 and 2.89 minutes, respectively. With correlation values of 0.999, linearity was found over 40-240 µg/ml FOR SOF and 10- 60 µg/ml for VEL. Precision displayed a %RSD of less than 2%. Accuracy investigations showed recoveries of 98.90-101.15 % for VEL and 99.06 – 100.21 % for SOF. Good sensitivity was demonstrated by low LOD and LOQ values. Stability- indicating capabilities with well- resolved degradation peaks was demonstrated by forced degradation investigations. A strong design space was created by QbD optimization. Conclusion: The QbD-based RP-HPLC method was developed was straightforward, quick, precise, accurate, and reliable. Sofosbuvir and Velpatasvir in bulk and pharmaceutical formulations can be routinely analyzed for quality using this technology.