Polyanhydride microspheres. IV. Morphology and characterization of systems made by spray drying

Abstract

Abstract The morphology of bioerodible polyanhydride microspheres produced by spray drying is described. Microspheres prepared from a variety of homo‐ and copolymers were studied and characterized using X‐ray powder diffraction, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Crystalline polymers, such as poly(sebacic anhydride) (P(SA)) and poly(fumaric acid) (P(FA)), yielded microspheres with a crenelated and porous surface, as judged by SEM. Polymers, with lower crystallinity, such as copolymers of carboxyphenoxypropane and sebacic acid P(CPP‐SA), yielded microspheres with a smooth external surface. Polymer crystallinity decreased after spray drying, for both blank and drug loaded microspheres.