Tomáš Holas

l-Serine and glycine based ceramide analogues as transdermal permeation enhancers: polar head size and hydrogen bonding

Novel transdermal permeation enhancers related to stratum corneum ceramides were investigated. The synthesis of a series of simple compounds based on two selected amino acids, L-serine and glycine, and their enhancement activities are reported. Glycine derivative 3 enhanced the permeation of theophylline through human skin in vitro 12.5+/-0.5 times. The relationships between properties of the polar head of the compounds and their activity are discussed.

Transkarbams with terminal branching as transdermal permeation enhancers

Transkarbams (T) represent novel group of highly active, non-toxic transdermal permeation enhancers. This study was focused on the influence of small symmetrical terminal branching on their enhancing activity. Series of T with terminal methyl or ethyl branching was prepared and their permeation-enhancing activity was compared to that of their linear analogues. The results showed completely a different behaviour from similarly branched alcohols, supporting the key role of the ammonium-carbamate polar head in the enhancing activity of T.