ABSTRACT
Introduction .................................................................................................................................... 311 Types of Cultured Skin Models...................................................................................................... 313
Epidermal Models....................................................................................................................... 313 Epiderme
ˆ ................................................................................................................................ 313
SkinEthic ..................................................................................................................................... 314 Full-Thickness Models ................................................................................................................ 315
EpidermFTe ˆ
........................................................................................................................... 315 Apligraf.................................................................................................................................... 315 Orcel1................................................................................................................................. 315 Episkine
ˆ ................................................................................................................................. 315
Bioengineered-Human Skin Equivalent................................................................................. 316 Conclusions .................................................................................................................................... 316 References....................................................................................................................................... 317
The skin’s potential as an alternative drug delivery route has only been realized during the past two decades [1]. Transdermal drug delivery provides advantages over other routes of administration by avoiding the first pass effect in hepatic and intestinal tissue and by maintaining steady-state plasma levels [2, 3]. The invasiveness of intravenous therapies and the diligence required for adhering to multiple oral dosing regimens are why many prefer the use of transdermal drug delivery systems [4]. More importantly, there is increased patient compliance when using these devices. Unfortunately, not all
drugs can be delivered in transdermal systems due to the innate barrier function of the skin. The stratum corneum or outermost layer of skin, which is composed of nonliving terminally differentiated stratified keratinocytes, is primarily responsible for this barrier. However, this barrier can sometimes be compromised by the use of permeation enhancers. Permeation enhancers are compounds that circumvent the permeability barrier by temporarily altering the structure of the stratum corneum [5, 6].
