ISSN(Online): 2319-8753 ISSN (Print): 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 4, Issue 1, January 2015 DOI: 10.15680/IJIRSET.2015.0401086 www.ijirset.com 19074 Development and Validation of a Stability Indicating Reverse Phase HPLC Method for Simultaneous Determination of Etodolac and Paracetamol in Its Tablet Dosage Formulation Mithlesh Rajput 1 , Hinna Hamid 2 , Manjeet Aggarwal 3 , Rakesh Kumar Khandal 4 * Department of Drugs and Pharma, Shriram Institute for Industrial Research, Delhi, India 1 Department of Chemistry, Jamia Hamdard, New Delhi, India 2 The National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India 3 Uttar Pradesh Technical University, IET Campus, Sitapur Road, Lucknow, Uttar Pradesh, India 4 ABSTRACT: A simple, sensitive, accurate, HPLC-UV method has been developed for the simultaneous determination of etodolac and paracetamol in presence of their degradation products in tablet combined dosage formulation. Chromatographic separation was achieved successfully by using phenomenex C18 column (150 mm x 4.6 mm, i.d. 5 m particale size) with an optimized mobile phase of ACN:H 2 O:H 3 PO 4 in the ratio of 500:500:0.25 (v/v/v) pH 3.0 with triethyamine. The mobile phase was run at a flow rate of 1 ml / minute under isocratic conditions with injection volume 10μl and the quantification of etodolac and paracetamol was carried out by UV detector at 274 nm based on peak area maeasurment. The reliability and performance of the proposed method were statistically validated with respect to system suitability, linearity, accuracy, precision (inter-day and intra-day), specificity, and robustness, limit of detection and limit of quantification. The method was found to be linear in the wide working range of 2 to 80μg/ml and 2.5-100μg/ml for both the analyte of interest with correlation coefficient 0.999 and 0.999 for etodolac and paracetamol respectively. The proposed method proved to be selective and suitable for indicating stability study for both etodolac and paracetamol in presence of any degradation product formed under different forced stress conditions (acidic, alkaline, oxidation, thermal and photolytic). The proposed validated method was successfully applied to the analysis of etodolac and paracetamol in their combined dosage form and thus can be routinely used for the simultaneous determination of etodolac and paracetamol when present in combined formulation. KEYWORDS: Etodolac, Paracetamol, UV-HPLC, Stability indicating method. I. INTRODUCTION Etodolac is chemically (R, S) -2- (1, 8-Diethyl-4, 9-dihydro-3H-pyrano [3, 4-b] indol-1-yl) acetic acid. Its molecular weight and formula are C 17 H 21 NO 3 and 287.35g/mol respectively [1]. Etodolac works by reducing the levels of prostaglandins, responsible for pain, fever and tenderness that occur with inflammation. Etodolac blocks the enzyme that makes prostaglandins (cyclooxygenase) thereby resulting into lower concentrations of prostaglandins. As a consequence, inflammation, pain and fever are reduced [2] [3].Various methods have been reported for determination of etodolac drug formulations and in biological samples. Reported methods are based on spectrophotometry method [4] [5] HPLC with UV detection [6], HPLC with mass spectrometric detection [7] for the determination of etodolac.