Preparation of polysaccharide composite films using cyclodextrin-conjugated chitosan for sustained release of hydrophobic drugs

Cyclodextrin-conjugated polysaccharides are often used as functional materials for biological applications, such as drug carriers, because the hydrophobic cavity of the cyclodextrin moiety can encapsulate molecules. Herein, β-cyclodextrin (β-CD)–conjugated chitosan (CD–CHI) for loading and sustained-release of low-molecular-weight hydrophobic drugs was synthesized, and polysaccharide composite films containing β-CD units were prepared from polyion complexes consisting of chondroitin sulfate C and CD–CHI by hot press techniques. β-CD units of the obtained CD–CHI were modified by 9.2% of the amino groups in CHI units. The synthesized CD–CHI was used as a raw material for polysaccharide composite films. The mechanical strength and swelling ratio of the obtained films were comparable to those of films without β-CD. Furthermore, thiabendazole (TBZ) was loaded into the polysaccharide composite films, and it was suggested that the loaded TBZ formed inclusion complexes with the β-CD units in CD–CHI. The loaded TBZ showed sustained-release ability, and the release mechanism from the films was analyzed and described using two kinetic models. Based on these results, polysaccharide composite films using CD–CHI are expected to be used as sustained-release carriers for hydrophobic drugs.