Method development and validation for simultaneous estimation of olmesartan medoxomil and hydrochlorothiazide by RP-HPLC

Abstract

A simple, fast, precise reverse phase isocratic high performance liquid chromatographic (HPLC) method has been developed for the simultaneous estimation of Olmesartan medoxomil (OM) and hydrochlorothiazide (HCTZ) in marketed formulations. Estimation of drugs in this combination was done with a C18 column [ODS UG 5 column, 250mm × 4.5mm] using mobile phase of composition acetonitrile and phosphate buffer (50:50 v/v, pH 6.8). The flow rate was 1.0 ml/min and the separation was monitored at 260nm. The retention time of HCTZ and OM were 3.6min and 4.3min respectively. The method was found to be linear over a range of 10-70ug/ml for OM and 6-42μg/ml for HCTZ. The method was validated according to the guidelines of International Conference on Harmonisation (ICH) and was successfully employed in the estimation of commercial formulations.