Engineering poly(ethylene oxide) buccal films with cyclodextrin: A novel role for an old excipient?

Inspired by the multiple roles cyclodextrins can play in polymeric systems, here we engineeredpoly(ethylene oxide) (PEO) films with (2-hydroxypropyl)--cyclodextrin (CD) as multipurpose ingre-dient. To shed light on the potential of CD in formulating PEO buccal films for the delivery of poorlywater-soluble drugs, we preliminarily assessed thermal and mechanical properties as well as wettabilityof films prepared at different PEO/CD ratios. PEO/CD platform containing 54% by weight of CD was cho-sen as the optimized composition since it matched acceptable mechanical properties, in terms of tensilestrength and elasticity, with a good wettability. The platform was tested as buccal delivery system for tri-amcinolone acetonide (TrA), a lipophilic synthetic corticosteroid sparely water soluble. Confocal Ramanimaging clearly showed that CD was homogeneously (i.e. molecularly) dispersed in PEO. Nevertheless,homogenous drug distribution in the film without TrA crystallization occurred only in the presence of CD.Finally, CD-containing PEO film placed in simulated buccal fluids provided a useful speed-up of TrA releaserate while showing slower dissolution as compared to PEO film. These results, as well as compliance withquality specifications of pharmaceutical manufacturing products, strongly support the soundness of thestrategy and prompt toward further applications of PEO/CD films in buccal drug delivery.