Spectrophotometric Method for Determination of promethazine Hydrochloride in Pharmaceutical formulation Based on coupling with 2-choloraniline in Presence of N-BromoSuccinimide

Abstract

A simple, rapid and sensitive spectrophotometric method for determination of trace amounts of Promethazine hydrochloric in aqueous solution is described. The method is based on using the oxidative coupling reaction of Promethazine hydrochloride with 2-Chloroaniline reagent in acid medium in the presence of N-bromoSuccinimide. The red color product is quickly converted to green colour, water soluble, the product which exhibit maximum absorbance at 595 nm, coefficient of determination 0.9974 Beer's law is obeyed over concentration range of (4-24µg/ml), with a molar absorptivity 7765.78 l/mol.cm, Sandal index of 0.04132 µg/cm2. The average recovery is 99.837% and Detection Limit (D.L) of 0.0435µg/ml, relative standard deviation does not exceed 2.185%, The proposed method was applied successfully for determination of PMZH in it’s pharmaceutical formulations.