Erschienen:
Proceedings of the National Academy of Sciences, 2017
Erschienen in:
Proceedings of the National Academy of Sciences, 114 (2017) 14, Seite 3631-3636
Sprache:
Englisch
DOI:
10.1073/pnas.1620636114
ISSN:
0027-8424;
1091-6490
Entstehung:
Anmerkungen:
Beschreibung:
Significance Human skin consists of distinct layers and is designed to prevent water loss and to keep harmful materials out, which makes transcutaneous drug delivery challenging. A model for drug diffusion within skin is introduced that as the only input requires experimental concentration profiles measured at three distinct penetration times. For the specific example of the antiinflammatory drug dexamethasone, the modeling shows that both free-energy and diffusivity profiles are highly inhomogeneous, which reveals the basic mechanism of epidermal barrier function: slow diffusion in the outer stratum corneum hinders fast penetration into the skin, whereas a pronounced free-energy step from the epidermis to the dermis underneath reduces long-time permeation. Targeted drug delivery strategies through skin must reflect these properties.