A Novel UV-Spectrophotometric Method for Simultaneous Estimation of Amlodipine and Captopril

Abstract

An UV-spectrophotometric method for simultaneous determination of amlodipine and captopril has been developed and validated. Simultaneous equation method is applied for the quantification of both drugs, which is based upon the measurement of absorbance at two wavelengths, λ_max = 236 and 213 nm for amlodipine and captopril, respectively, in 0.1 N HCl solutions. The calibration curves for amlodipine and captopril are linear in concentration ranges of 0.195 – 100 and 0.39 – 100 μg/mL, respectively. Accuracy of the method is 98 and 99% for amlodipine and captopril, respectively. The inter-day precision for amlodipine and captopril in terms of RSD is 10 and 8%, while the intra-day RSD is 6 and 9%, respectively. Sensitivity of the method in term of the limit of detection for amlodipine and captopril is 0.195 and 0.39 μg, respectively. The method gives 98% reproducible results.