¹Division of Chemistry, Department of Sciences and Humanities, Vignan's Foundation for Science, Technology and Research University, Guntur, India DOI : 10.12991/jrp.2018.91 A HPLC method was developed for the estimation of aspirin and omeprazole simultaneously in bulk drug and tablet dosage forms. 0.1 M potassium dihydrogen phosphate and acetonitrile in the ratio of 55:45 v/v at pH of 4.5 was used successfully as the mobile phase for the analysis of the selected drugs. Analysis of the selected drugs was carried out using Zodiac C18 (150 × 3.0 mm, 5 μm) column. The calibration range for omeprazole was 0.08-24 μg/ml, whereas, for aspirin was 0.65-195 μg/ml. The LOD and LOQ values were; 0.199 μg/ml and 0.65 μg/ml for aspirin, 0.024 μg/ml and 0.080 μg/ml for omeprazole, respectively. The percentage recovery of aspirin and omeprazole was found to be 99.75%-99.92% and 99.46%-99.57%, respectively. Percentage relative standard deviation (RSD%) was found to be in the range of 0.083%-0.085% for aspirin and 0.045%-0.047% for omeprazole. Forced degradation studies (such as alkaline, acidic, oxidative, thermal and photolytic degradation conditions) were performed on tablet sample as per the ICH guidelines. The peaks of degradants are well separated from the main peaks of aspirin and omeprazole. The proposed HPLC method was successfully applied for the quantification of aspirin and omeprazole in its pharmaceutical dosage forms without interference from common excipients. Keywords : Aspirin; omeprazole; forced degradation; stability studies; tablet dosage form