The present invention provides an intraoral rapid-disintegrating pharmaceutical composition which exhibits excellent intraoral disintegrating property and high hardness, and which can be applied, in particular, to a pharmaceutically active ingredient which is unstable in water. The pharmaceutical composition, which contains lactose and powdered cellulose, exhibits high hardness without prolongation of its intraoral disintegration time. When a disintegrating agent is further incorporated into the pharmaceutical composition, the hardness of the composition is increased without prolongation of its intraoral disintegration time. When magnesium aluminometasilicate, and one or more species selected from among silicic acid and silicic acid salts other than magnesium aluminometasilicate are further incorporated into the pharmaceutical composition, the composition exhibits higher hardness without prolongation of its intraoral disintegration time. The pharmaceutical composition of the present invention can be produced by means of a generally employed industrial production process without using a special preparation technique.
