COMBINED TABLETS USING HPLC

A simple, sensitive and isocratic reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed for the simultaneous determination of olmesartan medoxomil and amlodipine in pharmaceutical tablet formulations. HPLC analysis was carried out using reverse phase isocratic elution with a C18 column and a mobile phase of 0.05 M ammonium acetate pH 6.8 and acetonitrile in the ratio of 40:60, v/v. Detection of the analytes was achieved using UV detector at 239 nm. The retention times of olmesartan medoxomil and amlodipine were 2.50 and 3.94 respectively. Linearity of the method was found to be in the concentration range of 16-112 µgml-1 for olmesartan medoximil and 4-28 µgml-1 for amlodipine. The correlation coefficient value was greater than 0.9999 for both the analytes. The method is suitable for the estimation of both the components simultaneously in pharmaceutical tablet formulations