Affiliation: Faculty of Health Sciences,Fernando Pessoa University, Porto, Portugal.
Anti-inflammatory agents topically applied are appropriate in the treatment of skin diseases, restricting the therapeutical action to the affected area and reducing systemic side effects. On the other hand, systemic activity is the aim of transdermal delivery, which can be used to minimize the first pass metabolism but also to control systemic side effects, e.g., nonsteroidal anti-inflammatory drugs. The main limitation of this route is to overcome the stratum corneum, the outermost skin barrier. In order to achieve therapeutic concentrations and to improve the drug flux, permeation enhancers are used to optimize drug permeation through the skin. Cyclodextrins and their derivatives are capable of forming inclusion complexes with poor water soluble drugs improving their water solubility, bioavailability and stability, among other features. Cyclodextrins have been used as permeation enhancers although their mechanism it not yet well known. They can also be useful in the design of new drug carriers for skin delivery, by increasing the solubility of drugs hence providing high drug content systems. Improving the drug stability and promoting drug permeation are also desirable properties that cyclodextrins can provide to novel drug carriers. Several anti-inflammatory drugs have been incorporated into various skin delivery cyclodextrin-based systems such as liposomes, solid lipid nanoparticles and microemulsions.