Preparation and characterization of spray-dried polymeric nanocapsules

Recently, much interest has been generated by colloidal drug delivery syste ms such as nanocapsules because of the possibilities for controlled release , increased drug efficacy, and reduced toxicity after parenteral administra tion. Nanocapsules of poly-epsilon-caprolactone and Eudragit S90(R) were pr epared. However, these systems present physicochemical instability. To dry these nanocapsule suspensions with the view of obtaining a solid form, the spray-drying process was used. Spray-dried powders of nanocapsules of poly- epsilon-caprolactone and Eudragit S90(R) were prepared by atomization in a Buchi 190 Mini-spray dryer using colloidal silicon dioxide as a technologic al carrier. The morphological analysis of the surface at the powders showed that nanocapsules remain intact, and no change in particle size was detect ed after the spray-drying process. These results suggest that this method c an be an interesting alternative to dry nanocapsule suspensions.