Water-soluble β-cyclodextrin grafted with chitosan and its inclusion complex as a mucoadhesive eugenol carrier

Inclusion complex between water-soluble βCD-grafted chitosan derivatives (QCD-g-CS) and eugenol (EG) was investigated as a new type of mucoadhesive drug carrier. The QCD-g-CSs were synthesized with various βCD moieties ranging from 5 to 23%. Spontaneous inclusion complex of these derivatives and EG were found and confirmed by FTIR and simulation study. Self-aggregated formations of QCD-g-CS were found, according to fluorescence and TEM studies, where the formations were preferable for QCD11g-CS and QCD5-g-CS. EG can be included in both βCD hydrophobic cavity and hydrophobic core of QCD-g-CS self-aggregates, resulting in varying entrapment efficiencies. Degree of QCD substitution on QCD-g-CS plays an important role on their physical properties, due to steric hindrance. The QCD11-g-CS showed excellent mucoadhesion, compared to the QCD5-g-CS and QCD23-g-CS. Moreover, the inclusion complex between QCD-g-CS and EG tend to express higher antimicrobial activities against Candida albicans, Streptococcus oralis and Streptococcus mutans, than the native QCD-g-CS.