A mouthpiece for use in an inhaler for a particulate medicament, the mouthpiece having: an inlet and an outlet for the particulate medicament; a number of abutments which extend across the mouthpiece and which are arranged in a staggered configuration such that, in use, medicament is caused to break up as the medicament passes through the mouthpiece; wherein the abutments are blades having an elongate cross section in the direction of travel of the medicament.