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

## TL;DR

Researchers created a new type of film that can slowly release hydrophobic drugs using a chitosan-cyclodextrin material, showing potential for drug delivery applications.

## Contribution

A novel polysaccharide composite film using β-cyclodextrin-conjugated chitosan for sustained release of hydrophobic drugs was developed.

## Key findings

- The composite films showed mechanical strength and swelling comparable to films without β-CD.
- Thiabendazole formed inclusion complexes with β-CD units and exhibited sustained release.
- Two kinetic models were used to describe the drug release mechanism from the films.

## Abstract

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.

Polysaccharide composite films were prepared from polyion complexes composed of chondroitin sulfate C and β-cyclodextrin-conjugated chitosan by hot press techniques. The film can be used as a hydrophobic drug carrier with a tunable loading amount.