A process for producing microparticles, in which an aqueous solution of purified amylopectin-based starch of reduced molecular weight is prepared, the solution is combined with biologically active substance, an emulsion of starch droplets is formed in an outer phase of polymer solution, the starch droplets are made to gel, the gelled starch particles are dried, and a release-controlling shell is optionally applied to the particles, wherein at least one buffer substance having the ability of keeping the pH of the produced microparticles above 3 if exposing the microparticles to an aqueous evironment is added at any stage during the process.
Microparticles which essentially consist of said starch, have an amino acid content of less than 50 &mgr;g and have no covalent chemical cross-linking and which have the aktivity of keeping the pH above 3 if exposed to a aqueous environment,
一种生产微颗粒的工艺,在该工艺中,制备纯化的
直链淀粉基降低分子量淀粉的
水溶液,将该溶液与
生物活性物质结合,在聚合物溶液的外相中形成淀粉液滴的乳液,使淀粉液滴凝胶化、将凝胶化的淀粉微粒干燥,并在微粒上选择性地涂抹一层释放控制壳,其中,在此过程中的任一阶段添加至少一种缓冲物质,该缓冲物质在将微粒暴露于
水性环境中时,能使所制得的微粒的 pH 值保持在 3 以上。
微粒主要由上述淀粉组成,
氨基酸含量小于 50 微克,没有共价
化学交联,如果暴露在
水环境中,pH 值能保持在 3 以上、