ABSTRACT
The study of the percutaneous absorption and penetration of exogenous
compounds through human skin is relevant to transdermal drug delivery and
risk assessment of toxic chemicals. Around 40% of drugs under clinical evaluation
are related to delivery to or through the skin (1). The transdermal mode of
delivery offers the possibility of eliminating the pain and possible infection associ-
atedwith injections. It also enables thedrug tobypass thehepatic first pass associated
with oral delivery, and can provide sustained release of the drug for up to seven days
(2). An earlier review of transdermal delivery was provided by Roberts et al. (3).