Percutaneous absorption of 2-amino-4-nitrophenol in the rat

The absorption of sup1sup4C-labelled 2-amino-4-nitrophenol(ANP) in two hair dyeing formulations was investigated after application to the skin of rats. After 1 and 5 days, 0.21 and 0.36 % respectively, of the adminstered radioactivity was absorbed from formulation 1 which contained carboxymethylcellulose as a thickening agent. Absorption was greater (1.12 % after 1 day, 1.67 % after 5 days) from formulation 2 which contained oleic acid and isopropanol. Complementary studies of absorption after administration of (sup1sup4C)ANP by sc injection or oral gavage were also carried out. The radioactivity was rapidly excreted., predominantly in the urine, in both cases. Biliary excretion was also detected in an oral study. (Author)