A nasal delivery device for and a method of delivering a substance, in particular one of a liquid, as a suspension or solution, or a powder containing a medicament, especially systemic or topical pharmaceuticals, or a vaccine to the nasal airway of a subject.
1. A nasal delivery device for delivering a substance to a nasal airway of a subject, comprising:
a nosepiece adapted for fitting to a nasal cavity of a subject, the nosepiece including a first delivery outlet comprising a nozzle from which a liquid spray of the substance is delivered to the nasal airway of the subject, and a second delivery outlet through which a flow of gas, separate from an exhalation breath of the subject, is delivered to the nasal airway of the subject, wherein the second delivery outlet is separate from the nozzle, and the nozzle and the second delivery outlet are disposed such that the flow of gas that is delivered through the second delivery outlet first interacts with the liquid spray as delivered from the nozzle downstream of the nozzle;
a delivery unit for delivering the substance through the first delivery outlet of the nozzle;
a gas supply unit for supplying the flow of gas through the second delivery outlet;
a mouthpiece unit through which the subject in use exhales to cause closure of an oropharyngeal velum of the subject; and
an actuation mechanism for actuating the delivery unit and the gas supply unit on exhalation by the subject.
2. The delivery device of claim 1 , wherein:
the gas supply unit comprises a gas pump unit for delivering the flow of gas, the gas pump unit including a first chamber containing a gas and a first piston member which is movable in the first chamber to deliver the flow of gas from the first chamber through the second delivery outlet:
the delivery unit includes a pump unit for delivering the substance to the nozzle, the pump unit including a second chamber containing the substance and a second piston member which is movable in the second chamber to deliver the substance from the second chamber through the nozzle; and
the gas supply unit and the delivery unit are formed as an integrated unit and are actuatable by a driving unit for driving the first and second piston members to deliver the flow of gas through the second delivery outlet and the substance through the nozzle.
3. The delivery device of claim 2 , wherein the first piston member is configured to drive the second piston member.
4. The delivery device of claim 3 , wherein the driving unit is configured first to drive the first piston member alone and subsequently drive the first and second piston members in unison.
5. The delivery device of claim 2 , wherein the driving unit is configured to drive the first and second piston members in a single action.
6. The delivery device of claim 5 , wherein the first and second piston members are integrally formed.
7. The delivery device of claim 1 , wherein the second delivery outlet provides a substantially annular outlet.
8. The delivery device of claim 7 , wherein the second delivery outlet is disposed about the nozzle.
9. The delivery device of claim 1 , wherein more than 50% of the particles of the liquid spray have a diameter in the range of from about 1 μm to about 80 μm.
10. The delivery device of claim 9 , wherein more than 50% of the particles of the liquid spray have a diameter in the range of from about 10 μm to about 30 μm.
11. The delivery device of claim 1 , wherein the flow of gas delivered from the second delivery outlet guides the liquid spray that is delivered from the nozzle.
12. The delivery device of claim 1 , wherein the gas supply unit comprises a gas pump unit for delivering the flow of gas, the gas pump unit including a first chamber containing a gas and a first piston member which is movable in the first chamber to deliver the flow of gas from the first chamber through the second delivery outlet.
13. The delivery device of claim 1 , wherein the delivery unit includes a pump unit for delivering the substance to the nozzle, the pump unit including a second chamber containing the substance and a second piston member which is movable in the second chamber to deliver the substance from the second chamber through the nozzle.
14. The delivery device of claim 1 , wherein the actuation mechanism is configured to initiate actuation of the gas supply unit prior to actuation of the delivery unit, whereby the flow of gas is delivered through the second delivery outlet prior to delivery of the liquid spray from the nozzle.