Simultaneous Estimation of Phenylephrine Hydrochloride and Benzyl Alcohol by First Derivative Spectrophotometric Method

A simple, precise and economical procedure for the simultaneous estimation of Phenylephrine Hydrochloride (PHE) and Benzyl Alcohol (BEN) in formulation has been developed. PHE is a Vasocostracting agentandBEN is a Local anaesthetic agent. The absorbance values 229.6 nm and 274.2 nm of first derivative spectrum was used for the estimation of PHE and BEN, respectively without mutual interference. This method obeyed beer's law in the concentration range of 25-250 μg/ml and 0.125-1.5 mg/ml forPHE and BEN respectively, in Methanol: Water (1:1) ratio.The slope and intercept for PHE were -0.001 and -0.008 and for BENwere -0.028 and -0.001 respectively as determined by the method of least squares. The results were found satisfactory and reproducible. The method was applied successfully for the estimation of PHE and BEN simultaneously in dosage form without the interference of common excipients.