Agents for improving potentcy of the urinary bladder which comprise an amine compound of non-carbamate-type having an acetylcholinesterase-inhibiting action. Particularly, crystals of a tricyclic, condensed, heterocyclic derivative are provided, which possess an excellent action to inhibit acetylcholinesterase and an action to improve the excretory potency of the urinary bladder. As an example, crystals of of 8-[3-[1-[(3-fluorophenyl)-methyl]-4-piperidinyl]-1-oxopropyl]-1,2,5,6-tet- rahydro-4H-pyrrolo[3,2,1-ij]quinolin-4-one or a salt thereof and pharmaceutical compositions containing them are disclosed.