An automated in vitro dermal absorption procedure: I. Permeation of (14)C-labelled N,N-diethyl-m-toluamide through human skin and effects of short-wave ultraviolet radiation on permeation.

An automated in vitro dermal absorption (AIDA) analysis procedure is reported together with a novel design for an AIDA cell chamber for measuring the permeation of pesticides through human skin and other membranes. Tests to determine the permeation of the insect repellent N,N-diethyl-m-toluamide (DEET) through fresh, frozen and heat-separated split-thickness human breast skin demonstrated permeation of 48.0 ± 10.18, 24.0 ± 7.76 and 42.4 ± 8.57% (mean ± SD), respectively, by 48 hr. permeation through nitrile butyl rubber glove material was not detected whereas 47.2 ± 3.16% permeation through a dialysis membrane was observed. Short-wave ultraviolet (UV) radiation had no significant effect on DEET permeation. The merits of AIDA in facilitating the precise simulation of environmental conditions during permeation testing are discussed.