Abstract: A dry-powder, breath-powered inhaler device comprising at least one air inlet, a flow chamber and an air outlet leading to a mouthpiece, the flow chamber further comprising at least one drug-containing volume and at least one scraping means and a rotor assembly comprising an axis and at least one blade; wherein the inhalation action of the patient applied at the air outlet causes air to enter the at least one air inlet such that the air interacts with the at least one rotor blade causing the rotor to rotate and thus generate breath-driven, relative motion between the at least one drug-containing volume and the at least one scraping means, such that fine particles of powder are released from the drug-containing volume; the arrangement being such that the air exits the flow chamber via the periphery of the flow chamber, carrying out the fine particles to the outlet to be inhaled by the patient.