Abstract: A STUDY ON PERCUTANEOUS ABSORPTION OF AZONE WITH ~3H TRACER Shen Zilong; Lin Song （China Pharmaceutical University, Research Center, Nanjing 210009）ABSTRACT Azone is one of the best enhancer of cutaneous Penetration. The distribution of Azone in mice af-ter percutaneous absorption and in vitro diffusion of Azone through excised mice skins using tracer ~3H-Azone are studied． The concentration of Azone in rat’ s blood after percutaneous absorption is studiedalso. The ~3H-Azone is found widely distributed in lung ， liver． kidney ， fat ， heart ， brain and spleen af-ter percutaneous absorption. The total diffusion ratio of ~3H-Azone is 0． 70 per cent in 8 h． The peakconcentration（2．7μg／ml） of Azone in rat’ s blood appears at 2 h after percutaneous absorption， but re-mains l．6μg／ml at 24 h. Key words azone~3H-azone distribution percutaneous absorption