Spectrophotometric methods for the determination of dapsone

Two spectrophotometric methods are proposed for the micro determination of dapsone [Bis- [4-aminophenyl] sulphone] which is commonly used for the treatment of leprosy as antimicrobial drug. In the first method 1, 2 naphthoquinone-4-sulfonate sodium salt was used as a reagent for the colorimetric determination of the cited drug. This reagent was largely used for the determination of primary aromatic amines, a deep red paraquinoid condensation product results which can be measured at 475 nm in 50% acetic acid medium. The second method is coupling of the diazotized primary aromatic amino- groups in dapsone with barbituric acid, a compound possessing an active methylenic group. The concentration range for Beer's law compliance is 1.28-9 mug ml-1 with mean percentage recovery 99.22 +/- 1.697%. The methods were successfully applied for the determination of dapsone in its dosage forms