Development and Validation of Stability Indicating LC Method for Olmesartan Medoxomil

Abstract

The present method provides the detailed description of development and validation of a simple stability indicating reverse phase column liq. chromatog. method for olmesartan in the presence of its impurities namely Imp-A, Imp-B, Imp-C, Imp-D, Imp-E, Imp-F and Imp-G and degrdn. products generated from forced degrdn. studies. The drug substance was subjected to stress conditions of aq. hydrolysis, Oxidative, photolytic and thermal stress degrdn. The degrdn. of olmesartan was obsd. under acid hydrolysis, base hydrolysis and peroxide. The drug was found to be stable to other stress conditions attempted. Successful sepn. of the drug from synthetic impurities and degrdn. products formed under stress conditions was achieved on symmetry C18, 150 mm × 4.6 mm, 5 μ column using a phosphate buffer, Acetonitrile and Milli Q water. The developed LC method was validated with respect to specificity, linearity, accuracy, precision, raggedness and robustness. The assay method was found to be linear in the range of 250 μg·mL-1 to with 1000 μg·mL-1 correlation coeff. of 0.9999 and the linearity of the impurities was established from LOQ to 0.4%. Recoveries of assay and impurities were found between 98.5% and 101.2%. The developed LC method to det. the related substances and assay detns. of olmesartan can be used to evaluate the quality of regular prodn. samples and stability samples. To best of the authors' knowledge, the validated stability indicating LC method which separates all the impurities disclosed in this investigation was not published elsewhere. [on SciFinder(R)]