Evaluation of the percutaneous absorption and metabolism of some aminopropiophenones.

The absorption of diethylpropion (DEP I), dimethylpropion (DMP I) and some of their basic metabolites into and passage through the skin was investigated and a comparison of their metabolism following oral and percutaneous administration made. High percentages (60-80%) of DEP I and its metabolites and a small percentage of DMP I and its metabolites were taken up into the skin in less than 2 min--the remaining percentages of the compounds were absorbed into the skin by a first order process. The rate of appearance of the compounds in the blood, which reflects their rate of passage through the skin, did not correlated with their rate of absorption into the skin. More metabolism occurred with all the compounds after their oral administration than after their percutaneous application.