A simple, rapid, accurate, precise and economical reverse phase high performance liquid chromatographic method was developed for simultaneous quantification of two anti-hypertensive drugs, viz., Olmesartan medoxomil and Chlorthalidone. The separation of both the drugs was achieved on ODS C 18 column (250 × 4.6 mm id, 5 μm particle size) using a mobile phase of Potassium dihydrogen ortho phosphate buffer solution (at pH 4): Acetonitrile (25:75 v/v). The flow rate was 1.2 ml/min and detection was done at 240 nm. The retention time of Chlorthalidone and for Olmesartan medoxomil was 2.3 mins and 3.7 mins respectively. The proposed method was validated as per ICH guidelines. The linearity of the method was evaluated at a range of 50 to 300μg/ml and 31.25 to 187.5μg/ml for Olmesartan medoxomil and Chlorthalidone respectively. The Correlation Coefficient of Olmesartan Medoxomil and Chlorthalidone were 0.999 each. Precision studies were carried out and % RSD of peak areas of Olmesartan Medoxomil and Chlorthalidone was about 0.69 and 0.64 respectively. The percentage recoveries of both the drugs Olmesartan Medoxomil and Chlorthalidone from the tablet formulation were 100.12% and 100.10% respectively. Results obtained for LOQ, LOD and Robustness were well within the acceptance criteria. Validation results indicated that the method is linear, accurate, precise, and robust. The simple mobile phase composition makes this method cost effective, rapid, and non-tedious and can also be successfully employed for simultaneous estimation of both drugs in commercial products.
