Fluorimetric determination of some thiol compounds in their dosage forms

Abstract

A simple fluorimetric procedure was adopted for determination of three pharmaceutical compounds containing thiol groups namely, captopril, D-penicillamine and N-acetylcysteine. In this method, the drugs are treated with 1,2-naphthoquinone-4-sulfonic acid. The latter is reduced to 1,2-dihydroxynaphthalene-4-sulfonic acid which has a maximum fluorescence intensity at 480/318 nm (λEm/Ex). The method is sensitive to 0.5-4.5 μg ml-1 with minimum detectability 0.05 μg ml-1 (S/N=2), and has been applied to determine these three thiols in their dosage forms. The results obtained are compared favourably with those obtained by their pharmacopeial methods. © 2002 éditions scientifiques et médicales Elsevier SAS. All rights reserved.