Microspheres containing an antimetabolite drug 5-Fluorouracil were prepared from (poly(lactic) acide)(PLA) or poly(lactic acid)-polyethylene glycol(PLA-PEG) as the carrier by using a water-in-oil-in-water emulsion solvent evaporation technique. The conditions of the microspheres preparation such as polymer concentration in organic solvent, relative molecular weight of PLA-PEG and PLA/PEG mass ratio were discussed. The surface morphology and the size of the microspheres were observed by SEM. The drug content of microspheres was examined by TGA and the drug release in vitro was evaluated. According to the results, the drug content increased with the nano-silica used. The highest drug content in this study was 39.9%. The drug-release kinetics satisfied the requirements of controlled drug-release.
