Objective: To develop and validate stability indicating RP-HPLC gradient method for simultaneous estimation of impurities and degradation products from Olmesartan Medoximil and Hydrochlorothiazide tablet.Methods: The chromatographic separation was achieved by using Inertsil ODS (250 mm x 4.6 mm, 5μ) column. The mobile phase-A consists of 0.01M potassium dihydrogen phosphatebuffer pH 3.2 adjusted using orthophosphoric acids and acetonitrile as mobile phase-B. The flow rate was 1 ml/min, and chromatograms extracted at wavelength 225 nm.Results: The method was found linear from LOQ to 0.4% level with respect to target concentrations of Olmesartan Medoximil (1.6 mg/ml) and Hydrochlorothiazide (0.5 m/ml) for all impurities, with correlation coefficient found greater than 0.99. The method found robust in all deliberate variations of method parameters as a resolution between adjacent peaks found greater than 2.0. The % RSD results for precision and intermediate precision found less than 5.0%.Conclusion: The proposed analytical method was found to be robust, stability indicating and can be used for estimation of impurities and degradation products of Olmesartan Medoximil and Hydrochlorothiazide from tablet dosage form.Keywords: Stability indicating, RP-HPLC, ICH, Olmesartan Medoximil and Hydrochlorothiazid
