Percutaneous absorption of triclocarban in rat and man

The route and rate of excretion by rats of the germicide (1 4 C) Triclocarban formerly called trichlorocarbanilide, given by parenteral injection has been investigated. Blood levels based on radioactivity and by chemical determination after parenteral injection have been compared with those obtained after topical application of (1 4 C) Triclocarban in soaps and in dimethylformamide (DMF) through occluded rat skin has been studied. Other soaps and a hand cleanser containing (1 4 C) Triclocarban have been applied to rat skin without occlusion and the effects of duration of contact, concentration and the use of a solubilizer have been investigated. In humans, absorption of Triclocarban through skin after bathing daily for 28 days has been investigated by chemical analysis of blood and urine. The data show that elimination by the rat is rapid and complete principally via the faeces. Blood levels after parenteral injection are low and comparison of the radioactivity and chemical determinations suggest rapid metabolism of the Triclocarban. After application to the skin, blood levels based on 1 4 C are very low. Absorption of (1 4 C) Triclocarban through occluded rat skin was greater from DMF than from soaps. With non-occluded rat skin, absorption from soaps was less and was dependent on concentration but independent of duration of contact. The use of a solubilizer did not increase absorption through skin. No measurable Triclocarban (less than 25 ppb) was present in blood and urine samples of volunteers during or shortly after a 28-day intensive bathing regimen.