A New RP-HPLC Method for the Assay of Chlorthalidone and Olmesartan in Combined Dosage Forms

A sensitive and reproducible RP-HPLC method was described for the quantitative determination of chlorthalidone and olmesartan in combined dosage form. This method was based on high performance liquid chromatographic (HPLC) separation of chlorthalidone and olmesartan with the use of a reversed phase HPLC column [Hypersil BDS, C18, 100 x 4.6 mm, 5m] at mobile phase consisting of phosphate buffer (pH-3.3) and acetonitrile in the ratio of 55:45 v/v ambient temperature. The flow rate of the mobile phase was adjusted to 1.0mL/min and the injection volume was 10μL. Detection was performed by photodiode array detector at a wavelength of 210nm and the chromatographic runtime was 6 minutes for the analysis. The reliability and analytical performance of the proposed method, including linearity, range, precision, accuracy, detection and quantitation limits, were statistically validated. The proposed method can be useful in the quality control of combination drug products