A dry powder inhaler includes a chamber holding an actuator to which a powdered medicament is adhered. Air is drawn into the chamber through an inlet flow channel and exits through an outlet flow channel. The actuator oscillates in response to the air flow, dislodging powdered medicament to be entrained in the air flow and delivered to the patient. A retaining member prevents the actuator from exiting the chamber. Thus, the medicament may be delivered to the patient without the use of carrier particles.