210 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II. Recovery of Triclosan from shampoo-treated rats Recovery at 48 h Application Rinsings Patch Skin Rats (%) (Bg/7.5 cm 2) (Bg) (Bg) (•g cm -2) (No. of 0.05 89 (15 cm 2) 76.5+5.6 1.0 0.15 12 0.10 103 93.7+1.7 2.8+0.6 0.48 3 0.50 474 410 +63 7.4+3.4 1.40 3 0.75 671 563 •38 6.6+4.6 1.75 8 1.0 880 879 +51 18.6+3.4 2.40 3 2.0 1664 1717 +65.6 26.9-4-7.9 3.24 3 To 7.5 cm • (or 15 cm 2) clipped dorsal female rat skin, 0.1 ml (or 0.2 ml) shampoo containing various concentrations (w/v) of [all] Triclosan was applied followed by 0.1 ml (or 0.2 ml) H•O and spread over the skin for 1 min. After a further 9 rain the rats were rinsed, dried, a protective patch applied and transferred to individual meta- bolism cages. At 48 h after treatment the rats were killed and the patch and treated area of skin removed for analysis. in blood, based on the radioactivity expressed as [tg Triclosan, was very low and increased as the concentration of [alii Triclosan in the shampoo was raised (Table III), but it remained constant when the contact time was increased (Table IV). For a shampoo containing 0.055/0 [all] Triclosan the observed penetration was 0.16 [tg cm -2 during a 48 h period. On adjustment for an 81.3•o excretion of a subcutaneously-injected, known dose the corrected penetration figure is 0.197 [tg cm -2. The total amount of [alii Triclosan penetrating through the treated area of skin is, therefore, 2.95 [tg, or 3.3•o of the applied amount. For the other concentrations, the extent of penetration ranged from 2.8• to 4.1•. Application of [all] Triclosan in aerosol deodorai7t The mean amount of spray used per application was 1.454_-0.36 g which at a concentration of [all] Triclosan of 0.13/o meant that 1.45•0.36 mg [all] Triclosan was sprayed at the shielded rats. The mean concentration of [aH] Triclosan in the 1 x 15 cm • of shield around the treatment window was 13.24-6.2 [tg cm -• which was taken as a good measure of [aH] Triclosan applied to the treated area of skin. At 48 h after treatment, the protective patch contained 41 [tg [all] Triclosan and the residue in the treated area of skin was 9.74-4.8 [tg cm -•. Recovery of tritium in the excreta was equivalent to 41.7•_ 11.48 [tg [alii Triclosan for six rats,

PERCUTANEOUS ABSORPTION OF TRICLOSAN 211 o o