| 摘要 |
PROBLEM TO BE SOLVED: To provide sustained-release microparticles having a release profile which can effectively maintain the blood concentration of a drug over a long time, and at the same time allowing a smooth initial release after medication also when applying a hydrophobic drug.SOLUTION: The present invention relates to sustained-release microparticles containing a poorly water-soluble drug which contain a poorly water-soluble drug and a divalent or trivalent metal ion salt of polylactic acid comprising at least one carboxyl group at a terminal or a derivative thereof. The poorly water-soluble drug is entrapped into the divalent or trivalent metal ion salt of the polylactic acid or the derivative thereof. The sustained-release microparticles containing the poorly water-soluble drug have a particle diameter of 1-400 μm and contain no amphipathic block copolymer. Preferably, the polylactic acid or the derivative thereof has a number average molecular weight of 500-5,000 Dalton. Preferably, the poorly water-soluble drug is olanzapine, risperidone, ziprasidone, rivastigmine, naloxone naltrexone, sirolimus, tacrolimus, or the like. |
