DECAY-TYPE NUCLEAR PARTICLE FOR PHARMACEUTICAL FORMULATION

Provided is a core particle for a pharmaceutical preparation, capable of delivering a relatively large amount of a drug active ingredient, in particular, at a predetermined timing. This invention relates to a disintegratable core particle for a pharmaceutical preparation, which core particle is adapted for formation, on the particle surface, of a drug active ingredient-containing film, wherein (1) the core particle includes a pharmaceutically acceptable inorganic material and a disintegration promoting agent, (2) the inorganic material is poorly soluble in water, (3) the inorganic material has a content of from 50 to 95 wt%, and (4) the core particle has a bulk density of at least 0.6 g/mL.