Author(s): M.G.Revanth Kumar, N. Murali
A simple, rapid and accurate reversed phase HPLC method has been developed for the simultaneous estimation of olmesartan medoxomil and hydrochlorothiazide in bulk drug. The chromatographic method was based on reversed phase liquid chromatography using a shimpack GWS C18 column (250 x 4.6mm, 5µ) with UV detection at 274nm. The mobile phase consisting of acetonitrile and water in a ratio range (65:35) and at a flow rate of 1ml/min. Validation parameters such as system stability, linearity, precision accuracy, specificity, limit of detection (LOD), and limit of quantification (LOQ), stability of sample and standard stock solutions and robustness were studies to report in the ICH guidelines. The retention time of olmesartan and hydrochlorothiazide was 1.9 and 3.1min respectively. The method was linear over the concentration for olmesartan medoxomil 8- 24µg/mL and for hydrochlorothiazide 5-15µg/ml and the R2 is 0.999 & 0.999. The recoveries of olmesartan medoxomil and hydrochlorothiazide were found to be in the range of 98.7% and 99.6% respectively. The method was validated and was successfully employed for the analysis of pharmaceutical formulation containing olmesartan medoxomil and hydrochlorothiazide in combined tablet dosage form.