Aerosol generator for drug formulation and methods of generating aerosol

• US 6,854,461 B2
• Filed: 04/18/2003
• Issued: 02/15/2005
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Original Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Inventors: Nichols, Walter A., Grollimund, Gary E., Brookman, Donald L., Smith, Ulysses
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): MITCHELL, TEENA KAY
• Application Number:
  US10/418,101
• Publication Number:
  US 20040025865A1
• Time in Patent Office: 669 Days
• Field of Search: 128/200.14, 128/200.21, 128/200.24, 128/203.12, 128/203.16, 128/203.17, 128/203.14, 128/203.15, 128/203.26, 128/203.27, 128/203.28, 128/204.17, 128/205.13, 128/205.15, 128/205.16, 222/52, 222/57, 222/67, 222/92, 222/95, 239/302, 239/304, 239/320, 239/321, 239/329
• US Class Current: 128/203.16
• CPC Class Codes: A61M 11/007 Syringe-type or piston-type sprayers or atomisers
• CPC Class Codes: A61M 11/042 electrical
• CPC Class Codes: A61M 15/0066 with means for varying the dose size
• CPC Class Codes: A61M 15/008 Electronic counters
• CPC Class Codes: A61M 15/025 Bubble jet droplet ejection devices
• CPC Class Codes: A61M 2016/0024 with an on-off output signal, e.g. from a switch

Abstract

An aerosol generator and methods of delivering aerosol to a user inhaling on a mouthpiece when a pressure drop is detected within the mouthpiece are disclosed. A medicated fluid passing through a capillary passage is heated to vaporize the fluid and form the aerosol by condensation or mixture of the vaporized fluid with admixed air. A metering chamber allows consistent delivery of precise doses of fluid to the capillary passage. Once the pressure drop is detected, aerosol can be quickly delivered to the user as the user begins to inhale on the mouthpiece. The quick delivery of aerosol provides more efficient use of the user'"'"'s lung capacity.

Claims

1. An aerosol generator, comprising:

a reservoir containing a liquid;

a flow passage in fluid communication with the reservoir; and

a heater arranged to heat the liquid in the flow passage to produce a vapor, the vapor admixing with air to produce an aerosol;

wherein;

a) the reservoir comprises a chamber, a liquid stored in a bladder in the chamber, and a free weight which compresses the bladder such that the liquid can be subjected to substantially constant pressure;

b) the reservoir is removably attachable to a fluid delivery assembly of the aerosol generator;

c) the flow passage is defined by an elastomeric member which comprises at least a first depression which defines a metering chamber, the first depression being sized to contain a predetermined volume of the liquid; and

/or

d) the flow passage is defined by an elastomeric member which comprises a first depression which defines a metering chamber, a second depression which defines an inlet valve, and a third depression which defines an outlet valve.

2. The aerosol generator of claim 1, further comprising a capillary passage in fluid communication with the metering chamber, a motor and a camshaft, the camshaft including a plurality of camshaft lobes operatively associated with the first depression, second depression and third depression, the camshaft lobes being operable to close the inlet valve, open the outlet valve and compress the metering chamber during an aerosol delivery cycle in which liquid is supplied to the capillary passage.

3. The aerosol generator of claim 2, wherein the camshaft lobes are operable to open the inlet valve and close the outlet valve during a fill cycle in which fluid is supplied to the metering chamber.

4. The aerosol generator of claim 2, further comprising a stepper motor operatively coupled with the camshaft, the stepper motor rotating the camshaft to open and close the inlet valve and outlet valve.

5. The aerosol generator of claim 2, further comprising a dispensing piston which engages the elastomeric member during the aerosol delivery cycle.

6. The aerosol generator of claim 2, further comprising a power supply and a controller, the controller being operable to monitor a parameter of the heater and deliver power from the power supply to the heater such that the heater is maintained at a desirable temperature range during the aerosol delivery cycle.

7. The aerosol generator of claim 1, further comprising a controller and a pressure sensor, the pressure sensor being operable to send the controller a signal when the user inhales on an outlet of a mouthpiece.

8. The aerosol generator of claim 7, wherein the pressure sensor is operable to detect a pressure drop in an interior of the mouthpiece when the user inhales on the outlet of the mouthpiece.

9. The aerosol generator of claim 1, wherein the aerosol generator is a hand-held inhaler including a mouthpiece having an interior and an outlet and a pressure sensor, the interior of the mouthpiece is supplied air only through an air passage, and the aerosol generator further comprises a drive assembly which actuates the inlet valve and outlet valve within a predetermined time period after the pressure sensor detects a pressure drop in the interior of the mouthpiece as the user inhales on the outlet.

10. The aerosol generator of claim 1, wherein the liquid is a liquid medicament comprising a drug and a carrier and the aerosol generator is a hand held inhaler.

11. An aerosol generator, comprising:

a reservoir comprising a chamber, a liquid stored in a bladder in the chamber, and a free weight which compresses the liquid such that the liquid can be subjected to substantially constant pressure;

a flow passage in fluid communication with the reservoir; and

a heater disposed to heat a portion of the flow passage to produce a vapor, the vapor admixing with air to produce an aerosol.

12. The aerosol generator of claim 11, wherein the weight applies the substantially constant pressure to an outer surface of the bladder.

13. The aerosol generator of claim 11, wherein the reservoir is open to the atmosphere.

14. The aerosol generator of claim 11, wherein the weight is sized relative to the chamber so that the weight is constrained to move slidably in the chamber along a rectilinear path.

15. The aerosol generator of claim 11, wherein the weight has a spherical configuration.

16. The aerosol generator of claim 11, further comprising a flow conduit which penetrates a wall of the bladder and is fluid communication with the flow passage.

17. The aerosol generator of claim 11, further comprising a capillary passage in fluid communication with a metering chamber of the flow passage, a motor, a camshaft, an inlet valve, an outlet valve, the camshaft including a plurality of camshaft lobes operatively associated with the inlet valve, the outlet valve and the metering chamber, the camshaft lobes being operable to close the inlet valve and open the outlet valve and compress the metering chamber during an aerosol delivery cycle in which liquid is supplied to the capillary passage.

18. The aerosol generator of claim 17, wherein the camshaft lobes are operable to open the inlet valve and close the outlet valve during a fill cycle in which fluid is supplied to the metering chamber.

19. The aerosol generator of claim 17, further comprising a stepper motor operatively coupled with the camshaft, the stepper motor rotating the camshaft to open and close the inlet valve and outlet valve.

20. The aerosol generator of claim 11, further comprising a controller and a pressure sensor, the pressure sensor being operable to send the controller a signal when the user inhales on an outlet of a mouthpiece.

21. The aerosol generator of claim 11, wherein the liquid is a liquid medicament comprising a drug and a carrier and the aerosol generator is a hand held inhaler.

22. An aerosol generator, comprising:

a reservoir containing a liquid, the reservoir being removably attachable to a fluid delivery assembly of the aerosol generator;

the fluid delivery assembly including a flow passage and a heater, the flow passage being in fluid communication with the reservoir, the heater being arranged to heat the liquid in the flow passage to create a vapor which admixes with air to produce an aerosol.

23. The aerosol generator of claim 22, wherein the fluid delivery assembly is removably attachable to the aerosol generator.

24. The aerosol generator of claim 22, further comprising a drive assembly which is operably associated with the fluid delivery assembly to cause the liquid to move through the flow passage.

25. The aerosol generator of claim 24, further comprising control electronics, a mouthpiece and a pressure sensor, the pressure sensor being operable to detect a pressure drop caused by a user inhaling on the mouthpiece, the control electronics activating the drive assembly and the fluid delivery assembly so as to generate the aerosol when the pressure sensor detects a predetermined pressure drop.

26. The aerosol generator of claim 24, further comprising control electronics and a manually activated switch, the control electronics activating the drive assembly and fluid delivery assembly so as to generate the aerosol when a user activates the switch.

27. The aerosol generator of claim 24, wherein the fluid delivery assembly and the drive assembly are removably attached to each other by a snap-fit or twist-on engagement.

28. The aerosol generator of claim 22, wherein the liquid is a liquid medicament comprising a drug and a carrier and the aerosol generator is a hand held inhaler.

29. The aerosol generator of claim 28, wherein the liquid medicament is contained in a bladder in the reservoir.

30. An aerosol generator, comprising:

a reservoir containing a liquid;

a flow passage in fluid communication with the reservoir, the flow passage being defined at least in part by an elastomeric member, the elastomeric member including a depression defining a metering chamber sized to contain a predetermined volume of the liquid;

a capillary passage in fluid communication with the metering chamber; and

a heater arranged relative to the capillary passage so as to heat at least a portion of the capillary passage sufficiently to volatilize liquid contained in the portion of the capillary passage.

31. The aerosol generator of claim 30, wherein the elastomeric member comprises an elastomeric membrane which extends between inlet and outlet ends of the flow passage.

32. The aerosol generator of claim 30, further comprising a depression actuator operatively associated with the depression, the depression actuator being movable to deform the elastomeric material so as to remove liquid contained in the metering chamber.

33. The aerosol generator of claim 32, further comprising a rotatable camshaft including a lobe operably associated with the depression actuator to move the depression actuator.

34. The aerosol generator of claim 32, further comprising an inlet valve operable to allow liquid to enter the flow passage from the reservoir, and an outlet valve operable to allow liquid to enter the capillary passage.

35. The aerosol generator of claim 34, further comprising an inlet valve actuator which is operable to open and close the inlet valve, and an outlet valve actuator which is operable to open and close the outlet valve.

36. The aerosol generator of claim 35, wherein the camshaft further comprises lobes operably associated with the inlet valve actuator and the outlet valve actuator to open the inlet valve, close the outlet valve, and maintain the metering chamber in a condition to be filled by the liquid.

37. The aerosol generator of claim 36, wherein the camshaft is operable to close the inlet valve, open the outlet valve, and compress the metering chamber to deliver the liquid from the metering chamber into the capillary passage.

38. The aerosol generator of claim 30, wherein the liquid is a liquid medicament comprising a drug and a carrier and the aerosol generator is a hand held inhaler.

39. An aerosol generator, comprising:

a reservoir containing a liquid;

a flow passage in fluid communication with the reservoir, the flow passage being defined at least in part by an elastomeric member, the elastomeric member comprising first, second and third depressions, the first depression comprising an inlet valve, the second depression comprising an outlet valve, and the third depression defining a metering chamber sized to contain a predetermined volume of the liquid;

a capillary passage in fluid communication with the metering chamber; and

a heater arranged relative to the capillary passage so as to heat at least a portion of the capillary passage sufficiently to volatilize liquid contained in the portion of the capillary passage.

40. The aerosol generator of claim 39, wherein the first, second and third depressions each have a dome shape.

41. The aerosol generator of claim 39, wherein the elastomeric member comprises an elastomeric membrane which extends between inlet and outlet ends of the flow passage.

42. The aerosol generator of claim 39, further comprising a first actuator operatively associated with the first depression, a second actuator operatively associated with the second depression, and a third actuator operatively associated with the third depression, the third depression being movable by the third actuator to deform the elastomeric material so as to remove liquid contained in the metering chamber.

43. The aerosol generator of claim 42, further comprising a rotatable camshaft including a first lobe operably associated with the first actuator, a second lobe operably associated with the second actuator, and a third lobe operably associated with the third actuator.

44. The aerosol generator of claim 43, wherein the camshaft is rotatable to open the inlet valve, close the outlet valve, and maintain the metering chamber in a condition to be filled by the liquid.

45. The aerosol generator of claim 43, wherein the camshaft is rotatable to close the inlet valve, open the outlet valve, and compress the metering chamber to deliver the liquid from the metering chamber into the heater.

46. The aerosol generator of claim 39, wherein the liquid is a liquid medicament comprising a drug and a carrier and the aerosol generator is a hand held inhaler.