The invention relates to a
drug sustained release
microsphere for injection and a preparation method thereof. The preparation is a sustained-release
microsphere injection, the prepared microspheres are narrower in
particle size distribution, high in encapsulation efficiency and small in burst release rate, the
drug can be continuously released for four weeks to six weeks, a better administration
route is provided for patients with poor
gastrointestinal absorption, and meanwhile, the
drug tolerance and toxic and side effects can be reduced. The preparation method comprises the following steps: adding a cosolvent, and adjusting the proportion of a medicinal
active component and a biocompatible
high polymer material in an
organic solvent, the
mass percentage of the cosolvent and the
organic solvent, the
mass percentage concentration of a surfactant in an external water phase, and the proportion of the
mass of the
organic solvent and the mass of the external water phase, so as to prepare the biocompatible
high polymer material. The
microsphere preparation containing the active pharmaceutical ingredients is obtained in an emulsification mode, the burst release rate
in vitro within 24 hours is lower than 10%, the encapsulation efficiency is high, the preparation method is simple, and the microsphere preparation can be suitable for industrialization of the production process of the microsphere preparation.