Device, method and resistive element for vaporising a medicament

• US 20050063686A1
• Filed: 10/31/2002
• Published: 03/24/2005
• Est. Priority Date: 10/31/2001
• Status: Active Grant

• Current Assignee: GW Pharmaceuticals Limited (Jazz Pharmaceuticals Plc), Tyco Electronics UK Limited (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: GW Pharmaceuticals Limited (Jazz Pharmaceuticals Plc), Tyco Electronics UK Limited (TE Connectivity Ltd. (United Kingdom))
• Inventors: Downs, David, Whittle, Brian Anthony, Vanhinsberg, Anthony, Harper, Anthony Hamish, Melbourne, Christopher Robert, Bowyer, John Erwin Richard, Dave, Rajiv Bobby
• Granted Patent: US 7,088,914 B2
• Time in Patent Office: Days
• US Class Current: 392/390
• CPC Class Codes: A61K 9/007 Pulmonary tract; Aromatherapy
• CPC Class Codes: A61M 11/002 by flow deviation causing inertial separation of transported particles
• CPC Class Codes: A61M 11/041 using heaters
• CPC Class Codes: A61M 15/0045 using multiple prepacked dosages on a same carrier, e.g. blisters

Abstract

A device for vaporising a medicament (4). The device comprises a resistive element (9) on which the medicament is deposited. The device also comprises a source of electrical power which can be connected across the resistive element to vaporise the medicament. The element is configured to provide a central cool region (11) on which the medicament is deposited and a relatively hotter region (12) surrounding the cool region. Through holes (13) are also provided. The resistive element may be a mesh, foil or a tile on which a resistive pattern is deposited.

Claims

1. A device for vaporisation of a medicament, the device comprising:

a resistive element configured to heat the medicament positioned in thermal communication with the resistive element;

a source of electrical power;

a connector to connect the source of electrical power across the resistive element; and

a controller configured to control a supply of electrical power to the resistive element to vaporise at least a portion of the medicament;

wherein the resistive element is configured to produce, in use, a relatively cool central region and a relatively hot region at least partially surrounding the cool region.

2. A device according to claim 1, wherein the relatively cool central region is created by the absence of resistive material in the central region.

3. A device according to claim 1, wherein the relatively cool central region is achieved by providing at least one constricted region away from the central region which generates a higher current density away from the central region hence preferentially heating the constricted region.

4. A device according to claim 3, wherein the resistive element is configured such that, in use, a respective constricted region is positioned between the medicament and each point at which the element is connected to the source of electrical power.

5. A device according to claim 1, wherein the resistive element is provided with a number of through apertures.

6. A device according to claim 5, wherein the through apertures are slits.

7. A device according to claim 6, wherein the slits are positioned to provide a tortuous conductive path through the element to the central region of the element.

8. A device according to claim 1, wherein the resistive element is a foil.

9. A device according to claim 1, wherein the resistive element is a mesh which is sized so that, in use, the thermal mass of the medicament is sufficient to produce the relatively cool central region.

10. A device for vaporisation of a medicament, the device comprising:

a resistive element configured to heat medicament positioned in thermal communication with the resistive element;

a source of electrical power;

a connector to connect the source of electrical power across the resistive element; and

a controller configured to control a supply of power to the resistive element to vaporise the medicament;

wherein the resistive element is provided with a number of surface inconsistencies to.

11. A device according to claim 10, wherein the surface inconsistencies are through apertures.

12. A device according to claim 11, wherein the resistive element is a mesh.

13. A device according to claim 11, wherein the through apertures are slits.

14. A device according to claim 13, wherein the slits are positioned to provide a tortuous conductive path through the element to a central region of the element.

15. A device according to claim 10, wherein the surface inconsistencies are provided by a roughened surface of the element.

16. A device according to claim 10, wherein the resistive element comprises a physical barrier configured to contain the medicament in its molten state.

17. A device according to claim 10, wherein the medicament is a cannabis extract.

18. A device according to claim 17, wherein the device is configured to vaporize between 0.1 and 10 mg of cannabis extract.

19. A device according to claim 10, further comprising a plurality of resistive elements, each configured to heat medicament positioned in thermal comunication with the resistive element, wherein the device further comprises means for selectively vaporizing the medicament.

20. A device according to claim 19, further comprising means to bring the connector selectively into engagement with each of the resistive elements.

21. A device according claim 20, further comprising a means to advance the plurality of resistive elements selectively to a location where at least one resistive element can be brought into engagement with the connector.

22. A device according to claim 19, wherein the plurality of resistive elements is supplied on a carrier.

23. A device according to claim 22, wherein the carrier is a cassette having a first reel from which the elements are selectively advanced and a second reel on which spent elements are stored.

24. A device according to claim 10, further comprising a chamber configured to receive vaporized medicament, and a mouthpiece communicating with the chamber configured to allow a user to inhale the vapour from the chamber.

25. A device according to claim 24, wherein a one-way valve separates the chamber and the mouthpiece.

26. A resistive element configured to be in thermal communication with a medicament, comprising contact points configured to connect, in use, with an electrical power supply, wherein the resistive element is configured to produce, in use, a relatively cool central region and a relatively hot region at least partially surrounding the cool region.

27. An element according to claim 26, wherein the relatively cool central region is created by the absence of resistive material in the central region.

28. An element according to claim 26, wherein the relatively cool central region is achieved by providing at least one constricted region away from the central region which generates a higher current density away from the central region hence preferentially heating the constricted region.

29. An element according to claim 28, wherein the element is configured such that, in use, a respective constricted region is positioned between the medicament and each point at which the element is connected to the electrical power supply.

30. An element according to claim 26, wherein the resistive element is provided with a number of through apertures.

31. An element according to claim 30, wherein the through apertures are slits.

32. An element according to claim 31, wherein the slits are positioned to provide a tortuous conductive path through the element to the central region of the element.

33. An element according to claim 26, wherein the element is a foil.

34. An element according to claim 26, wherein the element is a mesh which is sized so that, in use, the thermal mass of the medicament is sufficient to produce the relatively cool central region.

35. A resistive element configured to heat medicament positioned in thermal communication with the resistive element, having contact points which are configured to connect, in use, with an electrical power supply, wherein the resistive element is provided with a number of surface inconsistencies to provide keying.

36. An element according to claim 35, wherein the surface inconsistencies are through apertures.

37. An element according to claim 36, wherein the element is a mesh.

38. An element according to claim 36, wherein the through apertures are slits.

39. An element according to claim 38, wherein the slits are positioned to provide a tortuous conductive path through the element to a central region of the element.

40. An element according to claim 35, wherein the surface inconsistencies are provided by a roughened surface.

41. A method for vaporising a substance positioned in thermal communication with a resistive element, the method comprising connecting the resistive element to an electrical power supply and controlling the supply of electrical power to the resistive element to vaporize the substance by varying the duty cycle of the power supply to ensure that the resistive element reaches a target temperature, and then reducing the duty cycle to maintain the target temperature for sufficient time to vaporise the substance.

42. A method according to claim 41, further comprising controlling the power to vaporise the substance without pyrolysis.

43. A method for vaporizing a substance according to claim 41, wherein there are a plurality of resisitive elements, the method further comprising selectively vaporizing the substance on the resistive elements in turn.

44. A method according to claim 43, wherein the selectively vaporising step comprises progressively moving at least one of the resistive elements into a vaporising position and connecting the electrical power supply to the resistive element in the vaporising position.

45. A method according to claim 41, further comprising measuring the resistance once the resistive element is connected to the soure electrical power supply and adjusting the duty cycle of the power supply to compensate for variations in the measured resistance.

46. A method according to claim 41, wherein the substance is vaporised in one inspiratory cycle.

47. A method according to claim 41, wherein the substance is vaporised in a number of inspiratory cycles.

48. A method according to claim 41, wherein the target temperature is selected such that only constituents in the substance which have a relatively low boiling point are vaporized.