While the contents in the fluidized bed granulator are flowed, while supplying the binder liquid intermittently or continuously into the fluidized bed granulator, the bulk drug powder is intermittently or continuously fed to the fluidized bed granulator A method for producing a drug substance-containing nucleus having an average particle size of 100 m to 500 m, which comprises charging and granulating, a drug substance containing nucleus, a pharmaceutical composition, and an orally disintegrating tablet.流動層造粒機内の内容物を流動させた状態で、結合液を断続的又は連続的に流動層造粒機内に投入しながら、原薬粉末を断続的又は連続的に流動層造粒機に投入して造粒することを含む、平均粒子径が100μm~500μmの原薬含有核の製造方法、原薬含有核、医薬品組成物、及び口腔内崩壊錠。
