Native and polymeric β-cyclodextrins in performance improvement of chitosan films aimed for buccal delivery of poorly soluble drugs

Abstract

β-Cyclodextrin (βCD) and its soluble polymeric derivative (EPIβCD) were used to improve the effectiveness of chitosan-based bucco-adhesive film formulations containing bupivacaine hydrochloride and triclosan as poorly-soluble model drugs. The film formulations were characterized in terms of swelling, mucoadhesion and in vitro drug release, while possible interactions between the components were investigated by DSC and FTIR analyses. For both drugs EPIβCD showed a higher solubilizing efficiency than βCD; however cyclodextrin effectiveness in improving the release rate from film formulations was influenced by their different interactions with chitosan. Free βCD acted as a channelling agent, favouring the film swelling, while EPIβCD due to interaction with chitosan caused an opposite effect. βCD was the optimal partner for bupivacaine-loaded films in terms of film swelling, mucoadhesion and drug release. Contrariwise, EPIβCD was the best partner for triclosan-loaded films, allowing the highest drug release rate increase, due to its higher solubilizing ability with respect to βCD. Addition of the suitable cyclodextrin enabled formulation of buccal films with suitable drug release properties.