Spectrophotometric Determination of chlorpromazineHydrochloride in Pharmaceutical Preparations by Oxidative coupling reaction


A simple , rapid and sensitive spectrophotometric method for the determination ofmicrogram amounts of chlorpromazine Hydrochloride drug in aqueous solution isdescribed. The method is based on the oxidative coupling reaction between chlorpromazinehydrochloride and N,N – dimethyl-p- phenylenediaminedihydrochloride (DMPD) in thepresence of sodium periodate and hydrochloric acid to form an intense red colored productwith maximum absorption at 525 nm . Beer's law is obeyed over the concentration rangeof(4-34) μg.ml-1 with moler absorptivity of 9.239x103 l. mol-1. Cm-1 and sandell's sensitivityof 0.038 μg.cm-2 . The method does not resort to temperature control or to solventextraction . The optimum conditions for all color development are described and theproposed method has been successfully applied for the determination of chlorpromazineHydrochloride in bulk drug and pharmaceutical preparations (Largactil drug).