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.