Molecular skin barrier models and some central problems for the understanding of skin barrier structure and function

A better understanding of the structure and function of the human skin barrier is a prerequisite for a more rational design of transdermal drug administration systems. The study of biological structural organisation is, however, confronted with many difficulties, and interpretations of skin barrier-related data should therefore be done with caution. The recently developed 'single gel-phase model' constitutes an attempt to interpret structural and functional skin barrier data from a biophysical standpoint.