The invention relates to a method for entraining in an airflow a medicament powder contained in a cavity having a cavity opening. Large airflow vortices are provided, for instance, by means of an obstacle in a flow passage. The airflow with large vortices is arranged to by-pass the cavity opening, thereby generating an eddy in the cavity which contributes to entraining the powder in said airflow. The invention also relates to a medical dispenser, for instance an inhaler, in which said method may be performed.
