Abstract
Skin drug delivery is an emerging route in the drug development, due to
its great advantages, thus leading to an urgent need to understand the
behaviour of active pharmaceutical ingredients into/through the skin.
This knowledge is crucial in the early stages of product design and
development. Yet, given the skin barrier properties as one of the first
body’s natural defence systems, it can act as an obstacle to the
successful outcome of a skin drug therapy. To unravel the mechanisms
underlying this barrier, reductionist strategies have designed several
models with different levels of complexity and integrity, using
non-biological and biological components. Besides the detail of
information and resemblance to the in vivo Human skin that eachin vitro model offers, the technical and economic efforts
required should be considered when selecting the most adequate model for
the intended research. This review provides an outline of the most
commonly applied skin models, including healthy and diseased conditions,
lab developed systems and commercialized models, their advantages and
limitations and, also an overview of the new trends in skin engineered
models.