Original Article DOI: 10.4274/tjps.galenos.2021.48861 Stability Indicating Assay Method For The Quantitative Determination Of Olaparib In Bulk And Pharmaceutical Dosage Form Short title: Stability Indicating Assay Method for Olaparib ANTIMA CHAUDHARY 1 , Rajiv Tonk 1 , Pankaj Dagur 2 , Suddhasattya Dey 3 , Manik Ghosh 2 1 Delhi Pharmaceutical Sciences And Research University, M.b Road, Pushp Vihar, Sector-3, Saket, New Delhi-110017, India 2 Department Of Pharmaceutical Sciences And Technology, Birla Institute Of Technology, Ranchi 3 Bengal College of Pharmaceutical Sciences & Research, Bidhan Nagar, Durgapur, West Bengal 713212 Corresponding Author Information Manik Ghosh manik@bitmesra.ac.in 9430360991 https://orcid.org/0000-0003-2846-2971 31.08.2021 18.10.2021 ABSTRACT Background: Olaparib is an orally active poly (ADP-ribose) PARP (polymerases) inhibitor known to destroy cancer cells with BRCA1 or BRCA2- deficiency. Objectives: An authentic, fast, distinct, and reliable Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) method was developed and promptly validated in tablet formulation for olaparib estimation. Materials and Methods: The proposed method is focusedon the separation of olaparib in reverse phase mode using a WATERS symmetry C18 (150 × 4.6 mm, 5µm) analytical column with a flow rate of 1.0 mL/min and the injection volume was keptat 20µL. The optimized mobile phase consists of ammonium acetate buffer (pH adjusted to 3.5 by glacial acetic acid): methanol in the ratio of 50:50 v/v. Results: The eluents were measured at 254 nm and the retention time for the drug encircled was about 4.32 min. The stress degradation studies of Olaparib were carried out under acidic, alkaline, oxidative, photolytic and thermal conditions in order to demonstrate the stability of the drug. The regression value of 0.998 showed that the developed method was linear over the range of 80µg/mL to 120µg/mL. The developed RP- HPLC method is accurate and precise. The method was statistically validated as per ICH guidelines. Conclusion: The proposed method is suitable and can be applied practically for the quantitative estimation of olaparib without any interference of the excipients used in the drug formulations. KEYWORDS: Olaparib, Poly ADP-ribose polymerase (PARP) inhibitor, RP-HPLC, Waters, ICH and Validation INTRODUCTION During the last decade, inactivation of poly (ADP-ribose) polymerase (PARP), a nuclear enzyme associated with a number of operations including DNA repair and cell death, has emerged as a possible individualised cancer therapeutic approach. 1,2,3,4 In cancer cells with a defective DNA damage repair system, such as those produced by BRCA gene mutations, PARP inhibitors, a new class of anticancer drugs, can cause tumor-specific synthetic lethality. 5,6,7,8 Olaparib (Fig. 1), veliparib, niraparib, and rucaparib are potent PARP inhibitors that have recently moved through advanced clinical studies as combination and/or solo targeted therapies, especially in breast and ovarian malignancies. Olaparib uncorrected proof