Stability-indicating HPLC Method for Simultaneous Determination of Atenolol, Aspirin, Lisinopril and Simvastatin in Bulk and Tablets

A Simple, accurate, specific and rugged reverse phase liquid chromatographic method was developed for the simultaneous estimation of atenolol, lisinopril, aspirin and simvastatin in bulk and tablet dosage form. A reverse phase gradient program has been developed to separate all the four active ingredients. A gradient programming has been done using 0.05M Phosphate buffer pH 2.5 adjusted with dilute phosphoric acid, acetonitrile in the ratio 70:30 from 0 min to 10 min, further increase the acetonitrile ratio from 30 to 70 from 10 min to 20 min, on a reverse phase C8 column (250×4.6 mm, 5 µ) with a flow rate 1 ml/min, monitored at 232 nm. The mean retention times of atenolol, lisinopril, aspirin and simvastatin were found to be 3.9, 5.8, 9.5 and 18.3min, respectively. The linearity was established for atenolol 12.5 to 75 µg/ml, lisinopril 2.5 to 15 µg/ml, aspirin 18.75 to 112.5 µg/ml, simvastatin 5 to 30 µg/ml. The proposed method was validated in terms of linearity, range, accuracy, precision, specificity, robustness and ruggedness and the method was successfully applied to the estimation of atenolol, lisinopril, aspirin and simvastatin in combined tablet dosage form.