Fluorimetric determination of some thiol compounds in their dosage forms

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 (lambdaEm/Ex). The method is sensitive to 0.5-4.5 mug ml(-1) with minimum detectability 0.05 mug 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. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.