The fate of the saccharin impurities toluene-2-sulphonamide and 2,3-dihydrobenz[d]isothiazole 1,1-dioxide in the rat [proceedings].

The Fate of the Saccharin Impurities Toluene-2-Sulphonamide and 2,3-Dihydrobenz( d]isothiazole 1,l-Dioxide in the Rat ANDREW G. R E W I C K * and LOUISE M. BALL? *Faculty of Medicine, University of Southampton, Southampton SO9 3 TU, U.K., and ?Pharmacology Branch, N.I.E.H.S., Research Triangle Park, NC 27709, U.S.A. The non-nutritive sweetener, saccharin (2,3-dihydro-3-oxobenz[d]isothiazole 1,ldioxide) is synthesized from toluene-2-sulphonamide by oxidation and subsequent ring closure. Commercial saccharin frequently contains toluene-2-sulphonamide (Stavric et al., 1974) and the ring-closed compound 2,3-dihydrobenz[d]isothiazole 1,l-dioxide as impurities. A knowledge of their metabolism and excretion is essential in assessing the possible significance of these compounds in the human diet and in long-term toxicity testing of saccharin in rodents.