An improved method for the colorimetric assay of thiacetazone in pharmaceutical preparations

Abstract

An improved colorimetric procedure for the determination of thiacetazone (tibione) has been developed. It is based on the complete hydrolysis of tibione in a concentrated alkaline medium, after which the hydrolytic product is subjected to diazotisation and coupling with α-naphthylethylenediamine dihydrochloride. The procedure suggested in this paper eliminates some disadvantages of the original method and affords reproducible assay results for tibione in galenical preparations.