Study on Improvement of Release Behavior of Protein Drugs from PELA Microspheres
改善蛋白质药物PELA控释微球释放性能的研究

The microspheres for protein controlled release were prepared by W/O/W double emulsion-stepwise solidification method. Monomethoxypoly (ethylene glycol)-b-poly-DL-lactide (PELA) was used as the wall material, with ethyl acetate(EA) as organic solvent of oil phase,and lysozyme as model protein. In order to increase the release rate after the burst release, the effects of polymer composition, the volume of internal aqueous phase and the concentration of NaCl in external aqueous phase were investigated. It showed that the NaCl concentration in external aqueous phase affected the release rate apparently. It was found that when the concentration of NaCl increased from 0.9% to 1.5 % , the release rate increased from 22 % to 45 % after 40 days of release study. Therefore the desired protein release profile could be achieved by selecting suitable concentration of NaCl in external aqueous phase.