MECHANISM OF PERCUTANEOUS ABSORPTION .3. EFFECT OF TEMPERATURE ON TRANSPORT OF NON-ELECTROLYTES ACROSS SKIN

[摘要] Polar and non-polar molecules appeared to diffuse through normal human abdominal epidermis by different molecular mechanisms characterized by different activation energies. The activation energy was generally higher for a non-electrolyte when it contained more than 1 polar group or when the polar character of the group was increased. Diffusion rates for more polar molecules were correspondingly lower. The high activation energies found for water and the polar alcohols are consistent with the hypothesis that they diffuse through bound-water regions in the hydrated stratum corneum. The activation energies for water, for a polar alcohol, and for a non-polar alcohol diffusing through thoroughly delipidized epidermis were similar and all approached the activation energy for the self-diffusion of water. These compounds probably diffuse through relatively large, water-filled channels in this delipidized tissue.