In vitro gentamicin sustained and controlled release from chitosan cross-linked films

A novel wound dressing film was investigated for controlled and sustained delivery of gentamicin, while covering and protecting the wound. Chitosan was cross-linked with Hexamethylene 1,6-bis (aminocarboxysulfonate) to prepare the wound dressing films. Cross-linking reaction was required to control the water retention and release of encapsulated gentamicin. Cross-linked films swell less and became more hydrophilic than chitosan film itself. However, this behavior was inversely proportional to the degree of cross-linking. In vitro gentamicin release from the cross-linked films, at physiological conditions of pH and temperature, was studied for 2 weeks. The effects of gentamicin initial concentration and cross-linking ratio on the kinetics of gentamicin release were evaluated. Results showed that the diffusion rate was governed by initial concentration of gentamicin and degree of cross-linking, since higher gentamicin initial concentration and degree of cross-linking promoted the slower release, while lower gentamicin initial concentration and degree of cross-linking promoted the faster one.