European Journal of Biomedical and Pharmaceutical Sciences

INDIRECT ESTIMATION OF DIPHENHYDRAMINE.HCL IN WASTEWATER AND PHARMACEUTICAL PREPARATIONS

Nief Rahman Ahmed*, Alaa Ali Hussein and Rawya Nathem Rashed

ABSTRACT

A simple, rapid, accurate and sensitive indirect spectrophotometric method for determination of diphenhydramine hydrochloride has been developed. The proposed method is based on the reaction between chloride ion and Mercury(II) thiocyanate (Hg(SCN)2), formation of a colored complex by the reaction between released thiocyanate and ferric ions to form red soluble product with maximum absorption at 462 nm. Beer’s law is obeyed over the concentration range of 2-28μg/ml, with molar absorptivity of 0.759x104 l/mol.cm. The present method is considered to be simple because it does not need either heating or hydrolysis or solvent extraction steps. The ingredients often formulated with diphenhydramine hydrochloride have been shown not to interfere, and the proposed method is suitable for the routine determination of diphenhydramine hydrochloride. The method has been successfully applied for the determination of diphenhydramine hydrochloride in pure form, pharmaceutical preparations(Tablets, Syrup and Ampules) and environmental wastewater sample.

Keywords: Diphenhydramine Hydrochloride, Mercury(II) thiocyanate (Hg(SCN)2).