A Preliminary Study of Crosslinked Alginate-Chitosan Microspheres for Delivery System

Glutaraldehyde cross-linked chitosan coated-alginate microspheres were prepared to improve site specificity in colonic drug delivery system. Microspheres were characterized by microscopic image analysis, DSC and IR to study the formation of microspheres structure as well as the chemical interactions between drug and polymer. Microscope observation showed good spherical and homogeneous of microspheres. The glutaraldehyde cross-linked microspheres could produce Schiff base reaction and decrease chitosan hydrogen bonding interaction with mucous membrane. The drug loading of chitosan coated-alginate microspheres reached 43% and in vitro release properties of microspheres without cecal contents reached 20.96% after 12 h. The release profiles indicated that microsphere has a satisfactory sustained release behavior. Glutaraldehyde cross-linked chitosan coated-alginate microspheres have a great potential use in drug delivery system.