Dual resistance dry powder inhaler
Described is a dry powder inhaler for inhalation of a dry powder composition. The inhaler includes an external housing that defines an internal passage. The inhaler also includes a mouthpiece, a compartment for holding a dry powder capsule or powder reservoir, and a powder fluidization and deagglomeration apparatus for directing airflow to the dry powder to generate airborne powder particles within the internal passage. When a user inhales through the mouthpiece, a first airflow pattern is generated that has a first airflow resistance, during which the fluidization and deagglomeration apparatus generates airborne dry powder particles within the internal passage. Upon reaching a threshold negative pressure value within the internal passage of the inhaler, a second airflow pattern is generated having a second airflow resistance that is lower than the first airflow resistance, which pulls the airborne dry powder into the user's lungs during the inhalation. Embodiments of elastomeric valves are also described.
1. A device for inhalation of a dry powder composition, comprising:
an external housing comprising a housing wall and having a proximal end, a distal end and a length therebetween, wherein the housing defines an internal passage having proximal, intermediate and distal regions along the housing length;
a proximal end opening, a distal end opening, and proximal region opening extending through the housing wall, each opening being in connection with the internal passage;
a dry powder compartment within the distal region of the internal passage;
a powder fluidization and deagglomeration apparatus within the intermediate region of the internal passage; and
a valve disposed at the proximal region opening, the valve having a closed position and an open position,
wherein in the closed position a first airflow path extends from the distal end opening to the proximal end opening having a first airflow resistance, and in the open position, a second airflow path is open having a second airflow resistance that is lower than the first airflow resistance and the first airflow path is at least partially blocked by the valve.
2. The device of claim 1 , wherein the valve is configured to open responsive to a threshold negative pressure within the proximal region of the internal passage.
3. The device of claim 1 , wherein the valve comprises a flexible component attached to only a portion of a proximal region opening perimeter.
4. The device of claim 3 , wherein the portion of the flexible component detached from the proximal region opening perimeter forms a flap that separates from the proximal region opening perimeter and at least partially recesses into the internal passage when a threshold negative pressure value is reached within the internal passage.
5. The device of claim 1 , wherein the valve comprises a flexible component having at least one slit to form at least one valve flap.
6. The device of claim 5 , wherein the at least one valve flap at least partially recesses into the internal passage when a threshold negative pressure value is reached within the internal passage.
7. The device of claim 2 , wherein the valve is a mechanical valve.
8. The device of claim 1 , wherein the dry powder compartment is a disposable capsule positioned within the distal region of the internal passage.
9. The device of claim 1 , wherein the dry powder compartment is a reservoir.
10. The device of claim 1 , wherein the powder fluidization and deagglomeration apparatus is in fluid communication with the dry powder compartment.
11. The device of claim 1 , wherein the powder fluidization and deagglomeration apparatus is detachable from the device housing.
12. The device of claim 1 , wherein the powder fluidization and deagglomeration apparatus is integrated with the device housing.
13. The device of claim 1 , wherein the external housing is substantially cylindrical along its length.
14. The device of claim 1 , wherein the valve has a profile that is substantially the same as the profile of the external housing adjacent the proximal region opening.