Nasal delivery method

1. A method of delivering a substance to the-nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject; and

delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject, wherein the gas flow entraining a substance is provided by actuation of a supply unit device.

2. The method of claim 1 , wherein the gas flow entraining a substance is separate to an exhalation flow of the subject.

3. The method of claim 2 , wherein the supply unit is actuated by the exhalation flow of the subject.

4. The method of claim 1 , further comprising the step of controlling the flow rate of the gas flow delivered by the supply unit device.

5. A method of delivering a substance to the nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject; and

delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject, wherein the gas flow entraining a substance is provided by an impeller driven by an exhalation flow of the subject.

6. A method of delivering a substance to the nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject;

delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject; and

providing a flow resistance to the gas flow exiting the other nostril of the subject such as to maintain a dynamic positive pressure in the nasal airway of the subject, wherein the gas flow, while under resistance, continues exiting the other nostril.

7. The method of claim 6 , wherein the dynamic positive pressure is of sufficient magnitude as to force open at least one of the auditory tubes or the sinus tubes.

8. The method of claim 6 , further comprising the step of adjusting the flow resistance in maintaining the dynamic positive pressure in the nasal airway of the subject.

9. The method of claim 6 , wherein the dynamic positive pressure is at least 5 cm H 2 O.

10. The method of claim 9 , wherein the dynamic positive pressure is at least 50 cm H 2 O.

11. The method of claim 10 , wherein the dynamic positive pressure is at least 100 cm H 2 O.

12. The method of claim 11 , wherein the dynamic positive pressure is at least 200 cm H 2 O.

13. The method of claim 6 , further comprising the step of providing at least one of a visual or an audible signal when a predeterminable pressure has been achieved in the nasal airway.

14. A method of delivering a substance to the nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject; and

delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject, wherein the gas flow entraining a substance is delivered at a rate of at least 20 liters per minute and provided by actuation of a supply unit device.

15. A method of delivering a substance to the nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject;

and delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject, wherein the gas flow entraining a substance is delivered at a rate of about 1 to 20 liters per minute and provided by actuation of a supply unit device.

16. The method of claim 15 , wherein the gas flow entraining a substance is delivered at a rate of about 3 to 15 liters per minute.

17. The method of claim 6 , 14 , or 15 , further comprising the step of using a pressure-sensitive valve to trigger release of the substance when a predetermined flow rate has been achieved.

18. The method of claim 17 , wherein the pressure-sensitive valve is not opened until the subject has maintained a predetermined flow rate, and can be closed when the flow rate drops below the predetermined flow rate so as to stop delivery of the substance.

19. The method of claim 1 , 6 , 14 or 15 , wherein the gas flow entraining a substance is provided by an exhalation flow of the subject, the substance is a dry powder contained in a dispersion chamber prior to being exposed and entrained in the exhalation flow, and there is a moisture-absorbing element disposed upstream of the dispersion chamber.

20. The method of claim 19 , wherein the moisture-absorbing element is a desiccant.

21. The method of claim 19 , wherein the moisture-absorbing element is a filter.

22. The method of claim 21 , wherein the filter acts as a flow resistor to the exhalation flow.

23. A method of delivering a substance to the nasal airway of a subject, comprising the steps of:

sealing one of the nostrils of a subject to an outlet of a delivery unit such as to prevent the escape of a gas flow through the one nostril;

closing the oropharyngeal velum of the subject; and

delivering a gas flow entraining a substance through the outlet at such a driving pressure as to flow around the posterior margin of the-nasal septum and out of the other nostril of the subject, wherein a metered dose of the substance is mechanically dispensed into a delivery chamber and wherein the gas flow entraining a substance is provided by actuation of a supply unit device.

24. The method of claim 23 , wherein the substance after being dispensed is gradually released from the delivery chamber into the gas flow.

25. The method of claim 1 , 6 , 14 , 15 or 23 , wherein the gas flow entraining a substance is provided by an exhalation flow of the subject, the substance is a dry powder, and the surface properties of the powder have been modified to prevent agglomeration of the powder when it comes into contact with the exhalation flow.

26. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein velum closure is provided by exhalation by the subject.

27. The method of claim 26 , wherein the exhalation is through a flow resistor so as to maintain a positive pressure differential between an oral cavity and the nasal airway of the subject sufficient to maintain the velum in a closed position.

28. The method of claim 27 , wherein the flow resistor is configured to maintain a positive pressure differential of at least about 5 cm H 2 O between the oral cavity and the nasal airway of the subject.

29. The method of claim 1 , 6 , 14 , 15 or 23 , wherein the gas flow entraining a substance is provided by an exhalation flow of the subject.

30. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , further comprising the step of: providing at least one of a visual or an audible signal on exhalation by the subject.

31. The method of claim 30 , wherein the visual signal comprises a movement of a display member into view.

32. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance comprises a dry powder.

33. The method of claim 32 , wherein the powder has a particle size distribution, a major fraction of which is in a range of about 1 to 10 μm.

34. The method of claim 32 , wherein the powder has a particle size distribution substantially in a range of about 1 to 10 μm.

35. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance comprises liquid droplets.

36. The method of claim 35 , wherein the liquid droplets comprise one of a solution or a suspension.

37. The method of claim 35 , wherein the liquid droplets have a particle size distribution, a major fraction of which is in the range of about 1 to 10 μm.

38. The method of claim 35 , wherein the liquid droplets have a particle size distribution substantially in a range of about 1 to 10 μm.

39. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance contains a medicament.

40. The method of claim 39 , wherein the medicament is for a treatment of a nasal condition.

41. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance comprises a cleansing agent for cleansing the nasal airway.

42. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance comprises an irrigating agent for irrigating the nasal airway.

43. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in delivering a substance to a posterior region of the nasal airway.

44. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in the treatment of nasal inflammation.

45. The method of claim 44 , in the treatment of rhinitis.

46. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in the treatment of nasal polyps.

47. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in the treatment of hypertrophic adenoids.

48. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in the treatment of secretory otitis media.

49. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , in the treatment of reduced olfaction.

50. The method of claim 1 , 5 , 6 , 14 , 15 or 23 , wherein the substance comprises a pharmaceutical.