DRUG DELIVERY DEVICE

• US 20080215005A1
• Filed: 05/15/2008
• Published: 09/04/2008
• Est. Priority Date: 03/23/1998
• Status: Active Grant

• Current Assignee: Alkermes Pharma Ireland Limited (Alkermes plc)
• Original Assignee: Alkermes Pharma Ireland Limited (Alkermes plc)
• Inventors: Lavi, Gilad, Tsals, Izrail, Carmel, Ehoud, Gross, Joseph, Yigal, Gil
• Granted Patent: US 7,998,117 B2
• Time in Patent Office: Days
• US Class Current: 604/141
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 31/135 having aromatic rings , e.g. ketamine, nortriptyline methadone A61K31/137
• CPC Class Codes: A61K 33/14 Alkali metal chlorides; Alkaline earth metal chlorides
• CPC Class Codes: A61K 33/22 Boron compounds
• CPC Class Codes: A61M 2005/1405 Patient controlled analgesia [PCA]
• CPC Class Codes: A61M 2005/14204 with gas-producing electrochemical cell
• CPC Class Codes: A61M 2005/1426 with means for preventing access to the needle after use
• CPC Class Codes: A61M 2005/14533 cam actuated
• CPC Class Codes: A61M 2005/31518 designed to reduce the overall size of an injection device, e.g. using flexible or pivotally connected chain-like rod members
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/1454 spring-actuated, e.g. by a clockwork
• CPC Class Codes: A61M 5/155 pressurised by gas introduced into the reservoir
• CPC Class Codes: A61M 5/158 Needles for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body
• CPC Class Codes: A61M 5/2046 Media being expelled from injector by gas generation, e.g. explosive charge
• CPC Class Codes: A61M 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/31571 Means preventing accidental administration for automatic syringes A61M5/20
• CPC Class Codes: A61M 5/31586 performed by rotationally moving or pivoted actuator, e.g. an injection lever or handle
• CPC Class Codes: Y10S 128/12 Pressure infusion
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A drug delivery device having a housing containing a gas generator controlled by an electronic controller. The gas generator generates gas into a reciprocable chamber, whereby reciprocation of the chamber causes a lever to reciprocate a pawl, and this action causes a ratchet to The device may also be provided with manually control for delivering a bolus dose of drug when necessary.

Claims

1. A drug delivery device comprising:

a housing containing a drug reservoir;

means for facilitating expulsion of drug from the drug reservoir;

a mechanism in communication with the facilitation means, operable to undergo incremental advancement and thereby drive the drug from the reservoir;

a member operatively associated with the mechanism to cause the incremental advancement of the mechanism as the member moves in a first direction; and

gas generating means located within the housing and operable to expand in a chamber, the member being in transmission relation to the chamber, whereby the member is driven by the movement of the chamber to advance the mechanism and thereby drive the drug from the reservoir in incremental fashion.

2. The drug delivery device according to claim 1, wherein the mechanism in communication with the facilitation means comprises a ratchet.

3. The drug delivery device according to claim 1, wherein the member moves in a reciprocable fashion.

4. The drug delivery device according to claim 3, wherein the movement of the reciprocable member causes the stepwise advancement of the mechanism.

5. The drug delivery device according claim 3, wherein the member is connected to a wall of the chamber, whereby the reciprocable movement of the member is driven by the expansion and contraction of the chamber.

6. The drug delivery device according to claim 1, wherein the chamber is elastically biased to revert to a contracted state, and wherein a venting means is provided to enable contraction of the chamber after gas generation has expanded the chamber.

7. The drug delivery device according to claim 6, wherein the venting means is passive and allows escape of gas therethrough when the chamber is pressurised relative to atmospheric pressure.

8. The drug delivery device according to claim 7, wherein the gas generator is adapted to generate gas at a rate higher than the rate at which venting occurs, whereby when the gas generator is active, the chamber becomes pressurised and expands, and when the gas generator is inactive, the venting means causes depressurisation and contraction of the chamber.

9. The drug delivery device according to claim 7, wherein the venting means comprises a permeable or semi-permeable member.

10. The drug delivery device according to claim 9, wherein the member is a silicone membrane.

11. The drug delivery device according to claim 1, wherein the mechanism is caused to advance as the chamber undergoes expansion.

12. The drug delivery device according to claim 1, wherein the mechanism is caused to advance as the chamber undergoes contraction.

13. The drug delivery device according to claim 1, wherein the member comprises a lever extending between the chamber and the mechanism.

14. The drug delivery device according to claim 1, wherein the mechanism comprises a rigid ratchet element having spaced formations on a surface thereof.

15. The drug delivery device according to claim 14, wherein the formations have a sawtooth cross section.

16. The drug delivery device according claim 14, wherein the formations are grooves on a surface of the rigid ratchet element.

17. The drug delivery device according to claim 14, wherein the mechanism includes a pawl carried on the member, the pawl being adapted to make ratcheting engagement with the formations on the rigid ratchet element.

18. The drug delivery device according to claim 17, wherein the pawl is resiliently biased against the formations on the rigid ratchet element.

19. The drug delivery device according to claim 18, wherein the pawl is in the form of a substantially flat spring an end of which bears against the formations on the rigid ratchet element.

20. The drug delivery device according to claim 18, wherein the formations are regularly spaced along the rigid ratchet element, and wherein the pawl comprises a pair of pawl members resiliently biased against the rigid ratchet element at different points along the length of the rigid ratchet element, the axial distance between the pair of pawl members being different to the axial distance between successive formations.

21. The drug delivery device according to claim 20, wherein the distance between successive formations is twice the distance between the pawl members.

22. The drug delivery device according to claim 18, wherein the formations are regularly spaced along the rigid ratchet element, and wherein the pawl comprises three or more pawl members resiliently biased against the rigid ratchet element at regular intervals along the length of the rigid ratchet element, the axial distance between each successive pair of pawl members being different to the axial distance between successive formations.

23. The drug delivery device according to claim 22, wherein the distance between successive formations is given by the number of pawl members multiplied by the distance between each successive pair of pawl members.

24. The drug delivery device according to claim 20, wherein the pawl is in the form of a resilient member which terminates in the pawl members which are in the form of a plurality of fingers biased against the ratchet element.

25. The drug delivery device according to claim 1, wherein the mechanism comprises a helical spring and one or more fingers which make a ratcheting engagement with the coils of the spring.

26. The drug delivery device according to claim 25, wherein one or more fixed fingers are mounted in fixed position relative to the housing, and one or more reciprocable fingers are mounted on the mechanism, such that when the one or more reciprocable fingers move in a first direction they engage the coils of the helical spring to drive the helical spring in the first direction, and when the one or more reciprocable fingers move in an opposite direction, the one or more fixed fingers engage with and hold the coils of the helical spring preventing it being driven back in the second direction, whereby the fixed and reciprocable fingers co-operate to drive the helical spring in one direction only.

27. The drug delivery device according to claim 26, wherein the or each finger is inclined in the first direction.

28. The drug delivery device according to claim 26, wherein the position of the one or more fixed fingers relative to the one or more reciprocable fingers is such that the helical spring is driven by the reciprocable fingers towards the fixed fingers.

29. The drug delivery device according to claim 26, wherein the minimum distance between the fixed and reciprocable fingers, respectively, is not greater than ten times the distance between adjacent coils of the helical spring when the helical spring is in a relaxed position.

30. The drug delivery device according to claim 29, wherein the minimum distance between the fixed and reciprocable fingers, respectively, is not greater than five times the distance between adjacent coils of the helical spring when the helical spring is in a relaxed position.

31. The drug delivery device according to claim 30, wherein the minimum distance between the fixed and reciprocable fingers, respectively, is not greater than twice the distance between adjacent coils of the helical spring when the helical spring is in a relaxed position.

32. The drug delivery device according to claim 31, wherein the minimum distance between the fixed and reciprocable fingers, respectively, is approximately equal to the distance between adjacent coils of the helical spring when the helical spring is in a relaxed position.

33. The drug delivery device according to claims 1, wherein the mechanism comprises a flexible ratchet element which is sufficiently stiff to drive medicament from the chamber when driven by the member, and sufficiently flexible to be bent before it meets the member, whereby the overall length of the device is reduced relative to a device in which a rigid ratchet element protrudes linearly from the mechanism before use.

34. The drug delivery device according to claim 33, wherein the mechanism comprises two or more co-operating flexible ratchet elements which are individually sufficiently flexible to be bent before they meet the member but when joined together are together sufficiently stiff to drive medicament from the chamber when driven by the member.

35. The drug delivery device according to claim 34, wherein the two or more co-operating flexible ratchet elements are bent away from one another before they meet the member.

36. The drug delivery device according to claim 1, further comprising electronic control means for controlling the delivery rate.

37. The drug delivery device according to claim 36, wherein the electronic control means comprises a timing mechanism which alternately energises and de-energises the gas generating mechanism for controlled periods.

38. The drug delivery device according to claim 36, wherein the electronic control means is programmable for different delivery programs.

39. The drug delivery device according to claim 1, further comprising means for manually adjusting the delivery rate.

40. The drug delivery device according to claim 39, wherein the member reciprocates to cause the incremental advancement of the mechanism and the means for manually adjusting the delivery rate comprises means for limiting the travel of the member, whereby the volume of drug delivered on each reciprocating stroke is controllable.

41. The drug delivery device according to claim 39, wherein the means for manually adjusting the delivery rate comprises means for delivering a bolus dose of drug.

42. The drug delivery device according to claim 41, wherein the means for delivering a bolus dose of drug comprises means for manually advancing the mechanism by one or more steps independently of the gas generating mechanism.

43. The drug delivery device according to claim 42 wherein the means for manually advancing the mechanism comprises means for manually advancing the lever extending between the chamber and the mechanism, operable from the exterior of the housing.

44. The drug delivery device according to claim 43, wherein the mechanism comprises a ratchet and wherein the means for manually advancing the mechanism comprises a pawl which is manually reciprocable from the exterior of the housing.

45. The drug delivery device according to claim 1 wherein the gas generation means comprises:

a first gas generation chamber having a housing, gas generation means, and a first diaphragm made of a low gas permeable material;

a second gas generation chamber having a housing containing gas generation means therein and a second diaphragm made of a high gas permeable material; and

means for controllably venting excess gas from the first chamber.

46. The device of claim 1 wherein the drug reservoir is in the form of a drug cartridge.

47. The device of claim 46 further comprising means for preventing activation of the gas generating means until the drug cartridge is operational position within the housing.

48. The device of claim 47 wherein the prevention means comprises a sleeve for receiving a drug cartridge, the sleeve slidably received by a recess in the housing, and a lip on the exterior edge of the sleeve for engagement with an interior surface of the housing,

50. The method according to claim 45, wherein the mechanism in communication with the facilitation means comprises a ratchet.

51. The method according to claim 45, wherein the member moves in a reciprocable fashion.

52. The method according to claim 47, wherein the movement of the reciprocable member causes the stepwise advancement of the mechanism.

53. The method according to claim 47, wherein the member is connected to a wall of the chamber, whereby the reciprocable movement of the member is driven by the expansion and contraction of the chamber.

54. The method according to claim 45, wherein the drug reservoir is provided separately from the housing, and the method further comprises the step of adding the drug reservoir to the housing before use.

55. The method according to claim 45, wherein means are provided for advancing the mechanism manually, and the method further comprises the step of manually advancing the mechanism to deliver a bolus dose of drug to the subject.

49. A method of delivering drug to a patient comprising the steps of:

affixing a drug delivery device to the surface of the patient'"'"'s skin, the drug delivery device comprising;

a housing containing a drug reservoir;

means for facilitating expulsion of drug from the drug reservoir;

a mechanism in communication with the facilitation means, operable to undergo incremental advancement and thereby drive the drug from the reservoir;

a member operatively associated with the mechanism to cause the incremental advancement of the mechanism as the member moves in a first direction;

and gas generating means located within the housing and operable to expand in a chamber, the member being in transmission relation to the chamber; and

activating the device whereby the member is driven by the movement of the chamber to advance the mechanism and thereby drive the drug from the reservoir in incremental fashion.