Isosters of transkarbam 12 as transdermal penetration enhancers

SUMMARY: Diploma thesis - Isosters of Transkarbam 12 as skin penetration enhancers Transkarbam 12 (5-(dodecyloxycarbonyl)pentylammonium-5-(dodecyloxycarbo- nyl)pentylcarbamate, T12) is a highly effective skin permeation enhancer. In this diploma thesis, T12 analogs with carbamate and carbonate function groups replacing the ester one were synthetised, and evaluated in vitro as skin permeation enhancers on excised porcine skin, using theophiline as a model drug. The results were expressed by an enhancing ratio and compared with the biological activity of T12. The enhancing activity decreases in the following sequence: ester, carbonate, carbamate. The results thus show that it is the ester group in the molecule of T12 which is essential for its extraordinary effect. In addition, homologues with a different length of the ending and connecting carbon chains were evaluated. While the length of the connecting carbon chain does not influence the biological activity significantly, nonyl to decyl ending carbon chains show the highest acceleration ability. It indicates that the length of the carbon chain, and not its lipofility, is important for the enhancing activity