Preparation and characterization of sustained release system based on polyanhydride microspheres with core/shell-like structures

A system for localized drug delivery composed of polyanhydride polymers was studied. The polymers were made via melt-condensation of sebacic acid (SA) with different amount of 1, 3-bis (p-carboxyphenoxy) propane (CPP) as copolymers. By double emulsion technique, microspheres with core/shell-like structure were fabricated. Hydrophilic compound Brilliant Blue G (BBG) was encapsulated in the inner core(s) region with loading efficiencies of 50% ~ 60% for poly (SA) and 40% ~ 45% for poly(SA-CPP) copolymer. Hydrophobic compound, curcumin, was encapsulated in the outer shell region at efficiencies about 90%. Drug release profiles show no initial burst and stable release rates. The studied delivery system was showed to provide stable release for both hydrophilic and hydrophobic compounds simultaneously.