Novel Determination of Anti-Hypertensive Combination; Benidipine Hydrochloride and Nebivolol Hydrochloride by High Performance Chromatographic Method

This research work was designed to establish and validate a novel stability indicating RP-HPLC method for the combined determination of Benidipine hydrochloride (BHE) and Nebivolol hydrochloride (NHE) in bulk and tablets, dependent on ICH guidelines.The assay method to analyse BHE and NHE was optimized with isocratic elution using acetonitrile: 0.1M acetate buffer (45:55, pH 5.1), Lichrospher ODS RP-18 column and flow pace of 1 ml/min. Total time for single run was 14 min. The injection quantity was 20μl, and was detected at 249nm. The method was verified on a concentration series of 1.25-10μg/ml (NHE) and 1.0-10μg/ml (BHE) for precision, accuracy and linearity. The LOD values were 0.059µg/ml and 0.028µg/ml for NHE and BHE, respectively. The LOQ values were 0.196µg/ml for NHE and 0.094µg/ml for BHE. The recovery percentages were 98.60-100.11% (BHE) and 98.94-101.50% (NHE) with relative standard deviation 0.250-0.694% (BHE) and 0.183-0.400% (NHE). The method was also observed to be efficient, and was sufficiently specific to measure BHE and NHE in the presence of stress-produced degradation products.