Cyclodextrins as skin-penetration enhancers

Abstract

Cyclodextrins (CDs) constitute a class of penetration enhancers that have advantages over other conventional penetration enhancers. Some CD derivatives form complexes with drug molecules to quickly establish equilibrium with free molecules of drug in the formulation, resulting in increased availability. CDs ameliorate the transdermal availability of drugs by improving their solubility and/or stability. They can also be used to avoid undesirable side effects associated with some drugs intended for transdermal application. Current research is examining the effectiveness of CDs as percutaneous penetration enhancers. The authors review the advances made in this field, compare various CDs as percutaneous absorption enhancers, and discuss their possible mechanisms of action and their safety profiles.