COLORIMETRIC DETERMINATION OF THYMOL, OXYPHENBUTAZONE AND MORPHINE HYDROCHLORIDE

Document Type : Original Article

Authors

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Assiut University, Assiut, Egypt

Abstract

A simple colorimetric method has been developed for the determination of thymol, oxyphenbutazone and morphine hydrochloride either in pure forms or in pharmaceutical preparations. The method is based on the formation of an azo dye from the condensation of diazotized 5-chloro-2,4-dinitroaniline with the titled drugs which contain a phenolic hydroxyl group. The absorption spectra for the coupling coloured products, for thymol, oxyphenbutazone and morphine hydrochloride exhibit absorption maxima at 592 nm (e= 46,153), 450 nm (e= 20,689) and 480 nm (e= 11,764) respectively. For each of the three studied drugs a typical calibration curve was obtained from linear regression analysis of absorbance at various drug concentrations. The developed colour for each drug was stable for at least 30 minutes. Optimum conditions for the colour formation have been determined. The application of this procedure to pharmaceutical preparations is given with good recoveries (99.69-100.50%).