Dispenser and method for entraining powder in an airflow
AssigneeAstraZeneca AB
InventorsOrest Lastow, Johan Remmelgas, John Briant
Life of this patent
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Abstract
The present disclosure 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 use 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 present disclosure also relates to a medical dispenser, for instance an inhaler, in which the method may be performed.
Claims16
A method for entraining in an airflow, flowing through a passageway having a longitudinal axis, a medicament powder contained in a cavity having a cavity opening in fluid communication with the passageway, wherein the passageway includes a lower surface region containing the cavity opening and an obstacle, which is fixed and rigid, located upstream of the cavity opening, and an upper surface region extending continuously parallel to the longitudinal axis from upstream of the obstacle to downstream of the cavity and located opposite the lower surface region, comprising:
- providing an airflow to be passed generally parallel to the longitudinal axis between the upper surface region and the lower surface region and outside the cavity along the cavity opening, the provided airflow initially having a first flow pattern;
- changing, upstream of the cavity opening, the first flow pattern into a second flow pattern having larger vortices than the first flow pattern;
- and
- passing, along the cavity opening, the airflow having said second flow pattern, thereby generating an eddy in the cavity which contributes to entraining the medicament powder in said airflow to provide less than about 10% retention of, medicament powder within the cavity, wherein the cavity always remains stationary relative to the passageway.
A medical dispenser, comprising:
- a powder containing cavity;
- a flow passage comprising a flat surface region, which is generally flat, located upstream of the cavity, wherein the powder containing cavity is fixedly and rigidly coupled to the flat surface region and the flat surface region comprises an opening from the flow passage into the powder containing cavity;
- and
- an obstacle located in the flow passage upstream of the powder containing cavity and not extending into the powder containing cavity, wherein the obstacle is configured to cause an airflow to pass around and over the obstacle and the obstacle is fixedly and rigidly coupled to and extends from a flow passage-defining wall portion that is positioned upstream of and at an incline with respect to said flat surface region.
Dependencies are inferred from the claim text.