ABSTRACT
Percutaneous absorption is defined as the rate and extent that a chemical is absorbed into and through the skin and into the systemic circulation. A major variable in percutaneous absorption is regional variation, where some body sites show extensive skin absorption, while the other sites show less absorption. Also, we are a world of individuals and percutaneous absorption will vary by individual, as well as anatomic site. Where percutaneous absorption is the passage of chemicals from the outside environment into and through skin, transepidermal water loss (TEWL) is the passage of water in the other direction, from the body through the skin into the outside environment. The question is whether percutaneous absorption and TEWL correlate and are predictable of one another.
