Stability‑Indicating RP‑HPLC Method for Simultaneous Estimation of Olaparib and Ibuprofen: Development, Validation and Stress Degradation Profiling

Abstract

A stability‑indicating reverse‑phase high‑performance liquid chromatographic (RP‑HPLC) method was developed and validated for simultaneous quantification of olaparib and ibuprofen. Separation was achieved on a C18 column in isocratic mode using phosphate buffer (pH 3.0) and acetonitrile (55:45, v/v) at 1.0 mL/min with UV detection at 254 nm. Olaparib and ibuprofen eluted at approximately 4.2 and 6.5 min, respectively, with acceptable peak symmetry, efficiency and resolution. The method was linear over 2–80 µg/mL for each analyte (r² ≥ 0.999), accurate (recoveries near 100%), and precise with low variability (%RSD generally ≤ 2%). Deliberate small variations in key parameters demonstrated robustness. Forced degradation under acidic, alkaline and oxidative stress generated degradation peaks that were separated from the parent peaks, confirming stability‑indicating capability. The procedure is appropriate for routine assay and stability profiling of olaparib and ibuprofen during formulation development and quality control.