| 摘要 |
PURPOSE:To obtain almost uniform polylactic acid microspheres, by preparing finely divided O/W or W/O emulsion containing a physiologically active substance and a polylactic acid and drying the emulsion in a liquid. CONSTITUTION:A physiologically active substance and a polylactic acid are dissolved in a common solvent (e.g. halogenated hydrocarbon, aromatic hydrocarbon, etc.) and the liquid mixture is emulsified in a poor solvent. In the above process, finely divided O/W or W/O emulsion is produced by ultrasonic treatment, the solvent of the mixed liquid is distilled off from the emulsion to form minute particles containing the physiologically active substance, and the particles are separated from the poor solvent by filtration or centrifugal separation and optionally dried to obtain the objective polylactic acid microspheres having an average particle diameter of 0.1-10mum.
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