Novel RP-HPLC–PDA method for comprehensive stability indicating and impurity profiling for concurrent estimation of abiraterone and Niraparib in bulk and tablet formulation
Abiraterone and Niraparib are widely used in cancer treatment particularly for managing prostate and ovarian cancers marketed with brand name Akeega. This study focuses on developing and validating an innovative, precise and stability-indicating RP-HPLC method designed to simultaneously quantify Abiraterone, Niraparib and their respective impurities in bulk and dosage form while also distinguishing degradation products formed under stress conditions. Chromatographic separation was achieved via isocratic elution using a Symmetry Shield RP-18 column (250 × 4.6 mm, 5 µm) with a mobile phase consisting of acetonitrile and buffer in a 40:60 v/v ratio. The flow rate was set at 1 mL/min at room temperature with a sample injection volume of 10 µL and detection was performed at 239 nm over a runtime of 24 min. The method was validated following ICH Q2 (R1) guidelines. Under optimized conditions, the retention times were noted as follows: Impurity A at 3.186 min, Impurity B at 4.771 min, Abiraterone at 6.409 min, Impurity C at 8.147 min, Impurity D at 10.132 min, Niraparib at 11.739 min, Impurity 1 at 13.456 min, Impurity 2 at 15.166 min, Impurity 3 at 16.976 min, and Impurity 4 at 18.396 min. Strong linearity was observed within the concentration ranges of 125–750 µg/mL for Abiraterone and 2.5–15 µg/mL for its impurities (A, B, C, D), as well as 25–150 µg/mL for Niraparib and 2.5–15 µg/mL for its impurities (1, 2, 3, 4). The percentage recovery of both drugs ranged from 99.8 to 100.6% across three concentration levels. The percentage RSD for both precision and robustness was within acceptable limits, while forced degradation studies demonstrated the method’s stability-indicating capacity by clearly differentiating between the active analyte peaks and degradation products. By enabling simultaneous detection and quantification in a single run, this method effectively reduces analysis time and improves efficiency, supporting pharmaceutical quality control processes and ensuring compliance with regulatory standards.