Abstract:
A First order derivative spectroscopy and RP-HPLC methods were developed and validated for simultaneous estimation of Ramipril and Cilnidipine as API and its capsule dosage form. A simple and easy UV spectrophotometric method with good sensitivity has been developed for simultaneous quantification of Ramipril and Cilnidipine. The method employed First order derivative method based on the measurement of absorbance at two wavelengths, 255 and 223.63 nm, ZCP of Ramipril and Cilnidipine, respectively. The calibration curve was linear in a concentration range of 5-30 μg/ml for Ramipril and 2-12 μg/ml for Cilnidipine. The RP-HPLC method has shown adequate separation of Ramipril and Cilnidipine as API and its capsule dosage form. The separation was achieved on a Enable C18 (250 mm X 4.6 mm i.d, 5 μm particle size) with an gradient system of Methanol: Acetonitrile: Water (pH 8 is adjusted with triethyl amine) in the ratio of 50: 40: 10 v/v. The mobile phase at a flow rate of 1.2 ml/min, Injection volume 20 μl and wavelength of detection used was 218 nm. The retention time for Ramipril and Cilnidipine was obtained as 1.663±0.1min and 5.333±0.1min, respectively. The linearity of the proposed method was investigated in the range of 10-60 μg/ml and 10-60 μg/ml for Ramipril and Cilnidipine, respectively. Correlation coefficient was 0.9984 and 0.9972 for Ramipril and Cilnidipine, respectively. The developed method was validated as per ICH guideline, for its accuracy, precision, LOD & LOQ and the results were found to be satisfactory.