A compound represented by the formula (I), salt thereof, or hydrate thereof has an excellent anti-pruritic effect and an excellent effect in terms of metabolism. The topical formulation of the present invention has excellent skin absorption properties of the compound represented by the formula (I), salt thereof, or hydrate thereof. Furthermore, the topical formulation of the present invention is excellent in stability because ingredients are hardly bled after long-term storage.wherein R represents hydroxyl, C1-6 alkoxy optionally substituted with C1-6 alkoxy, or amino optionally substituted with C1-6 alkyl.
