Development and Validation of Rp-hplc Method for Simultaneous Estimation of Lisinopril and Amlodipine Besylate in Tablet Dosage Form

A simple, specific, precise, and accurate reversed-phase HPLC method was developed and validated for simultaneous estimation of lisinopril and amlodipine besylate in tablet dosage forms. The separation was achieved by Hypersil ODS-BP C18 column (250 mm × 4.6 mm; 5.0 μm) using methanol: phosphate buffer at pH 6 adjusted with orthophosphoric acid (30: 70, v/v) as eluent, at a flow rate of 1 mL/min. Detection was carried out at wavelength 212 nm. The retention times of lisinopril and amlodipine besylate were 3.88 min and 2.716 min, respectively. The linearity was established over the concentration ranges of 20–80 μg/mL and 20–80 μg/mL with correlation coefficients (r 2 ) 0.9999 and 0.9993 for lisinopril and amlodipine besylate respectively. The mean recoveries were found to be in the ranges of 98.33–101.37% and 98.90–100.70% for lisinopril and amlodipine besylate respectively. The proposed method has been validated as per ICH guidelines and successfully applied to the estimation of lisinopril and amlodipine besylate in their combined tablet dosage form.