Metabolism and excretion of di(p-aminophenyl) sulphoxide in different animal species.

Rabbits, rats and guinea-pigs were treated with di(p-aminophenyl) sulphoxide and their urines examined by an analytical method which permits the simultaneous determination of this compound and of dapsone [di(p-aminophenyl) sulphone] which is a possible product of metabolic oxidation. The method gives for each drug the total of free compound plus acid-labile conjugates. All three species excreted unchanged drug together with dapsone. With rats and guinea-pigs about 33% of the excretion is dapsone, but with rabbits only 6 to 12%. The rate of combined excretion is much greater in rabbits than in the other two species. These results are discussed in relation to the significance of di(p-aminophenyl) sulphoxide as a drug in the treatment of leprosy.