A preparation for oral administration comprising: a pregelatinized starch comprising N-[4-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]-(2R,3R)- 2,3-tetramethylene-butyl]-(1'R,2'S,3'R,4'S)-2,3- bicyclo[2,2,1]heptanedicarboxyimide hydrochloride (lurasidone) represented by the formula (1) as an active ingredient； a water-soluble excipient； and a water-soluble polymeric binder, the preparation exhibiting an invariant level of elution behavior even when the content of its active ingredient is varied.
