Controlled delivery of taxol from microspheres composed of a blend of ethylene-vinyl acetate copolymer and poly (d,l-lactic acid).

'Large' (30-100 microns) and 'small' (10-30 microns) size range taxol-loaded microspheres composed of a blend of biodegradable poly (d,l-lactic acid) (PLA) polymer and nondegradable ethylene-vinyl acetate (EVA) copolymer were prepared using the solvent evaporation method. Encapsulation efficiencies were between 95-100% for taxol in 50:50 EVA:PLA blend microspheres. Between 10-13% of the total taxol content of the microspheres (0.6% w/v taxol loading) was released in 50 days. Using the chick chorioallantoic membrane (CAM) model, the taxol microspheres released sufficient taxol to produce vascular regression and inhibition of angiogenesis. This taxol-loaded microsphere formulation may have potential for the targeted delivery of taxol to a tumor via arterial chemoembolization.