Pharmacokinetics of the dermal route of exposure to volatile organic chemicals in water: a computer simulation model.

ABSTRACT

A kinetic model of dermal absorption of nonpolar organic nonelectrolytes in dilute aqueous solutions is described. The model uses systems dynamics STELLA software and is designed for a Macintosh computer. The model assumes the outer stratum corneum layer of skin to be the rate-determining barrier to dermal absorption and assumes that both stratum corneum and viable epidermal layers have storage capacity for lipophilic solutes. The model predicts between 30 and 94% of experimental results with humans under the same conditions. The degree of departure between experimental and theoretical results is inversely related to the solute's octanol/water partition coefficient, which is consistent with the most recently hypothesized mechanisms of transport of molecules across the dermal barrier. The model has potentially useful applications for risk assessment if used within its defined limits.