Spectrophotometric determination of metformin hydrochloride via oxidative coupling reaction with 1-naphthol in pharmaceutical and environmental water sample

Abstract

A simple, rapid, accurate and sensitive spectrophotometric method for determination
of metformin hydrochloride has been developed. The proposed method is based on
the oxidation of 1-naphthol by sodium hypochlorite and coupling with metformin
hydrochloride in the presence of sodium hydroxide to form an intense blue soluble
product with maximum absorption at 580 nm. Beerˈs law is obeyed over the
concentration range of 2-20μg/ml, with molar absorptivity of 3.66x104
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 metformin hydrochloride have been shown not to interfere, and the
proposed method is suitable for the routine determination of metformin
hydrochloride. The method has been successfully applied for the determination of
metformin hydrochloride in pure form, pharmaceutical preparations(Tablets) and
environmental water sample .