The present invention relates to an inhaler device (1) with a guide gear (7) having teeth each comprising two sections with different profiles/surfaces. An upper section has an inclined/radius surface (3.1) to form a ratchet being engaged by a corresponding pawl (2) to provide an unidirectional rotation. A section close to a base of the guide gear has a flat surface (3.2) around which a strip-shaped blister (5) is rolled. This enables holding blister in a secure manner while providing unidirectional rotation of the gear.
