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.