Multicomponent spectrophotometric assay of sulphacetamide and photodegradation products.

A multicomponent, spectrophotometric method has been developed for the simultaneous determination of sulphacetamide, sulphanilamide and major degradation products in photolysed solutions. It is based on a three component (Sulphacetamide, sulphanilamide and azobenzene-4, 4'-disulphonamide) assay at pH 4.0 using 258, 268 and 320 nm as analytical wavelengths. The blue oxidation product of sulphanilamide is determined independently at 550 nm. The reproducibility of the method judged by the analysis of synthetic mixtures, is within +/- 5%. The method is stability indicating for the assay of sulphacetamide in degraded eye-drop preparations and could also be conveniently used for photodegradation studies.