Preparation of starch-based drug delivery system through the self-assembly of short chain glucans and control of its release property

Abstract

Here, we report a starch-based carrier system for the delivery of insoluble bioactive compound via oral route. We utilized the intrinsic characteristics of debranched amylopectins that self-assemble into a spherical microparticle in aqueous environment to encapsulate guest molecules. Upon complexation with β-cyclodextrin, the model bioactive compound, curcumin (CUR), was effectively incorporated into the starch microparticles (SMPs) to form CUR-CD@SMPs during the self-assembly reaction. The stability of encapsulated curcumin against environmental stresses, such as photodegradation and chemical oxidation, was greatly enhanced upon encapsulation. The size of CUR-CD@SMPs could be precisely controlled from 0.3 μm to 2 μm by modulating the rate of debranching reaction. A change of release profiles from concave-downward to sigmoidal form was observed upon increasing the size of CUR-CD@SMPs, suggesting that the release site could be controlled by modulating the crystallinity or size of the carrier microparticles.