Simultaneous Estimation of Amlodipine, Atenolol and Hydrochlorothiazide in Bulk and Tablet Dosage Form by RP-HPLC Method

A simple, accurate, rapid and precise isocratic reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous determination of Amlodipine, Atenolol and Hydrochlorothiazide in capsules. The chromatographic separation was carried out on an cosmosil packed column 5C18-MS-I I analytical column (250×4.6 mm; 5 μm) with a mixture of Phosphate buffer:Acetonitrile:Methanol pH 6 adjusted with Ortho phosphoric acid (30:20:50, v/v) as mobile phase; at a flow rate of 1 ml/min. UV detection was performed at 240nm. The retention times were 2.637, 3.148 and 8.492min. for Hydrochlorothiazide, Atenolol and Amlodipine respectively. Calibration plots e linear (r2>0.998) over the concentration range 2-12μg/ml for Amlodipine , 10-60μg/ml Atenolol and 2-12μg/ml for Hydrochlorothiazide. The method was validated for accuracy, precision, specificity, linearity, and sensitivity. The proposed method was successfully used for quantitative analysis of capsules. No interference from any component of pharmaceutical dosage form was observed. Validation studies revealed that method is specific, rapid, reliable, and reproducible. The high recovery and low relative standard deviation confirm the suitability of the method for routine determination of Hydrochlorothiazide, Amlodipine and Atenolol in bulk drug and capsule dosage form.