Simultaneous estimation of ramipril and amlodipine in bulk and tablet dosage form by RP-HPLC method

Abstract

A Simple and precise HPLC method was developed for the simultaneous estimation of Ramipril and Amlodipine in pure drug and pharmaceutical dosage forms. The separation was carried out using C18 Column (250 × 4.6 mm i.d. 5 μm particle size), with mobile phase compressing of Acetonitrile, Sodium phosphate buffer and Methanol in the ratio of 50: 20:25 v/v/v, pH= 6.8 (pH adjusted with OPA). The flow rate was 0.8 ml/min and the detection was carried out using PDA detector at 210 nm. The retention times were 2.64 and 7.45 mins for Ramipril and Amlodipine respectively. Calibration curves were linear with correlation coefficient 0.998 and 0.996 over concentration range of 1-16 μg/ml for Ramipril and 0.2-3.2 μg/ml for Amlodipine respectively. Recovery was found in between 100.21% and 100.82% for Ramipril and Amlodipine respectively. Method was found to be reproducible with relative standard deviation (R.S.D) for intra and inter day precision less than 2%. The method was validated by evaluation of different parameters such as accuracy, linearity, precision, LOD and LOQ.