| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for preventing the production of crude particles in a step of freeze-drying an aqueous suspension of polylactic acid fine particles, and to provide a method for producing polylactic acid particles for an eye transparent tissue-visualizing agent. <P>SOLUTION: A method for controlling the production of crude particles on the freeze-drying of an aqueous suspension of polylactic acid fine particles includes (a) a step of preparing an aqueous suspension of polylactic acid fine particles containing a dispersing agent and 3.5-10% of mannitol, wherein the step includes (i) adding a solution obtained by dissolving polylactic acid in a water-miscible organic solvent to a dispersing agent aqueous solution under stirring, and then adding mannitol, or (ii) adding a solution prepared by dissolving the polylactic acid in the solvent to a dispersing agent/mannitol aqueous solution containing the dispersing agent and the mannitol under stirring, and (b) a step of freeze-drying the suspension in a glass container; and a method for producing polylactic acid particles for a transparent tissue-visualizing agent includes the steps (a) and (b). <P>COPYRIGHT: (C)2013,JPO&INPIT |
