Development and Validation of UV Spectrophotometric Method for Simultaneous Estimation of Olmesartan Medoxomil and Chlorthalidone in Bulk and Tablet

Based on the fact that no work has been reported so far for a spectrophotometric method for simultaneous estimation of olmesartan medoxomil and chlorthalidone in pharmaceutical dosage form. A precise and selective UV spectrophotometric method has been developed for the simultaneous estimation of olmesartan medoxomil (OLM) and chlorthalidone (CHL) in bulk and tablet dosage form. The spectrophotometric detection was carried out at an absorption maximum of 256 nm and 275 nm using methanol as solvent. Validation of analytical method was performed as per the ICH guidelines Q2A and Q2B. OLM and CHL demonstrated linearity in the concentration range of 5-20 μg mL with r of 0.998. The method was found to be linear over the range (r values of 0.997 for OLM and 0.998 for CHL), accurate (recovery; 100.51% for OLM and 99.84% for CHL), and highly precise (% RSD of 0.422 for OLM and 0.882 for CHL in intra-day study, and 0.71 for OLM and 0.934 for CHL in inter-day study, respectively) for analysis of both the drugs in bulk and tablet formulations. This method has been found suitable for estimation of both combination drugs in bulk and tablet formulations.