1998 Volume 58 Issue 3 Pages 155-163
The penetration of four drugs through a living skin equivalent (LSE) was compared with that via Wistar rat and human cadaver skins. Comparatively rapid penetration of 5-fluorouracil, indomethacin and dexamethasone through LSE was observed compared with that through rat and human skins, with flux 15-54 times larger than that of human skin and with a much shorter lag time. Penetration through LSE was enhanced by 2.5-4 times in the presence of d-limonene as compared with that without the enhancer. Scanning electron microscopic observations showed that the stratum corneum (SC) of LSE has many cracks and cell junctions were not fully closed, probably due to the lack of organized extracellular lipids, whereas rat skin had closed intercellular spaces and human skin was tightly closed. Thus, the LSE had an incomplete barrier function which was not fully equivalent to that of human SC. Our results attested that since permeability through LSE was much larger than that via Wistar rat and human skins, LSE was not a good model for evaluating skin permeation. The permeability coefficient (Kp) values predicted from physicochemical properties hardly agreed with experimental Kp for human skin.
