Paper Title Preparation and Evaluation of PLGA Microspheres Containing Bone Morphogenetic Protein for Controlled Release

The method of water in oil in water (w(1)/o/w(2)) was utilized to prepare BMP/PLGA microspheres. Various preparing parameters, including polymer concentration in oil phase, volume ratio of inner water phase to oil phase, emulsification concentration in external water phase were altered during the microspheres production. The effects of these changes on the size of the microspheres, drug loading, encapsulation efficiency were examined. And the morphological characteristics, drug-releasing function of the microspheres were investigated. The results show that the BMP/PLGA microspheres is good at morphology with the particles diameter at 0.5 mu m similar to 5 mu m, the envelopment ratio76.1%, and the ratio of drug loading 1.14%.However, the initial burst release of the microspheres occurred. The initial BMP burst release exceeded 18% within 1.5 days, and approximately 75% of the drugs was released within 43.5 days was observed for BMP from BMP-loaded microspheres and followed the Higuchi matrix model. So, the release behavior of microspheres showed the feasibility of BMP-loaded microspheres as controlled release devices.