Certain molecules, called chemical penetration enhancers (CPEs) help drugs absorb through the skin. After analyzing more than 100 different CPEs to better understand how they manage to increase skin permeability, the researchers engineered more than 300 new CPEs. The design of the new CPEs was based on the researchers' understanding of the molecular forces that are associated with CPE safety and potency. They then screened the new CPEs, first using computer technology and then testing the most promising ones in the laboratory environment. The molecules identified broaden the number of CPEs that can be used in the design of transdermal, cosmetic and pharmaceutical products.
"The methods used in this research not only increase our ability to create effective new CPEs, but they also will expand our ability to evaluate potential new CPEs for safety and efficacy," said Mitragotri. "By enhancing our ability to deliver drugs topically, we will be able to reduce the number of drugs that must be given by injection."
The skin is composed of several layers. The top layer, Stratum Corneum (SC) is made of dead cells that contain proteins and lipid molecules which are arranged in bi-layers. The SC is a significant barrier to the absorption of drug molecules across the skin. CPEs help drug molecules penetrate into the skin by changing the structure of the SC.
Different CPEs penetrate the skin in unique ways. For example, some make microscopic holes in the SC by removing lipids. Others insert themselves
Contact: Barbara Bronson Gray
University of California - Santa Barbara