5-fluorouracil-loaded chitosan coated polylactic acid microspheres as biodegradable drug carriers for cerebral tumours

The development of injectable microspheres for anticancer drug delivery int o the brain is a major challenge. The possibility of entrapping 5-fluoroura cil (5-FU) in chitosan coated monodisperse biodegradable microspheres with a mean diameter of 10-25 um was demonstrated. An emulsion of 5-FU (in water ) and polylactic acid (PLA) dissolved in acetone-dichloromethane mixture wa s poured into an aqueous solution of chitosan (or poly-vinyl alcohol) with stirring using a high-speed homogenizer, for the formation of microspheres. 5-FU recovery in microspheres ranged from 44-66% depending on the polymer and emulsification systems used for the preparation. Scanning electron micr oscopy revealed that the chitosan coated microspheres had less surface micr opores compared to PVA based preparations. The drug release behaviour from microspheres suspended in phosphate buffered saline exhibited a biphasic pa ttern. The amount of drug release was much higher initially (similar to 25% ), followed by a constant slow release profile for a 30 days period of stud y. This chitosan coated PLA/PLGA microsphere formulation may have potential for the targeted delivery of 5-FU to treat cerebral tumours.