Multiple dosage injector

• US 8,915,889 B2
• Filed: 01/30/2013
• Issued: 12/23/2014
• Est. Priority Date: 08/05/2008
• Status: Active Grant

• Current Assignee: Antares Pharma Incorporated
• Original Assignee: Antares Pharma Incorporated
• Inventors: Cox, Janice L., Rust, Matthew, KraMer, Thomas E., Hoeft, Peter
• Primary Examiner(s): Vu, Quynh-Nhu H
• Assistant Examiner(s): Zhang, Jenna
• Application Number:
  US13/754,092
• Publication Number:
  US 20130158508A1
• Time in Patent Office: 692 Days
• Field of Search: 604 68- 72, 604134-139, 604/110, 604207-211, 604/220
• US Class Current: 604/208
• CPC Class Codes: A61M 2005/2403 Ampoule inserted into the ampoule holder
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31545 Setting modes for dosing
• CPC Class Codes: A61M 5/31566 Means improving security or handling thereof
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31593 Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir

Abstract

A medicament dispensing mechanism is disclosed that is configured to eject successive doses of the medicament from a medicament chamber. An embodiment of the dispensing mechanism includes a housing and a plunger rod configured for ejecting the doses of medicament from the chamber. The dispensing mechanism further includes an actuation mechanism that comprises a trigger associated with the housing and having a ready and a fired position with respect thereto. The trigger is configured for manipulation by a user for successive movement in a generally axial dosing motion from the ready position to the fired position in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the doses of a predetermined volume and a resetting motion from the fired position to the ready position that comprises axial rotation, wherein the trigger is uncoupled from the plunger rod during the resetting motion.

Claims

1. A dispensing mechanism configured to eject successive doses of a medicament from a medicament chamber, the dispensing mechanism comprising:

a housing;

a dosage adjuster configured to adjust a volume of each of the successive doses of medicament;

a plunger rod aligned along an axis, the plunger rod configured for ejecting the successive doses of medicament from the chamber;

an actuation mechanism that comprises a trigger associated with the housing and having a ready position and a fired position with respect to the housing, the trigger being configured for manipulation by a user for successive movement in;

a dosing motion from the ready position to the fired position in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the successive doses of medicament, and

a resetting motion from the fired position to the ready position that comprises axial rotation of the actuation mechanism with respect to the housing, wherein the trigger is uncoupled from the plunger rod during the resetting motion; and

an anti-retrograde mechanism associated with the actuation mechanism and configured to prevent movement of the actuation member in a direction opposite to an operational direction associated with each of the dosing motion and the resetting motion;

wherein the anti-retrograde mechanism prevents the actuation mechanism from returning to the ready position associated with the dosing motion from the fired position associated with the dosing motion.

2. The dispensing mechanism of claim 1, wherein the trigger comprises a plurality of ready positions and fired positions disposed in sequence with each other, and wherein the ready positions are circumferentially spaced about the housing.

3. The dispensing mechanism of claim 1, wherein the anti-retrograde mechanism prevents movement of the actuation mechanism in a direction opposite the operational direction associated with each of the dosing motion and the resetting motion through at least a portion of the dosing motion and resetting motion.

4. The dispensing mechanism of claim 3, wherein the anti-retrograde mechanism is associated with the trigger for preventing rearward movement thereof from the ready position against the direction of the resetting motion, and wherein the anti-retrograde mechanism is associated with the trigger for preventing rearward movement thereof from the fired position against the direction of the dosing motion.

5. The dispensing mechanism of claim 4, wherein:

one of the trigger and housing includes a projection; and

the other of the trigger and housing includes a track for receiving the projection and defining the dosing and resetting motions, wherein the track has a first tab disposed therein with a free end configured for engaging the projection and preventing rearward movement thereof from the fired position against the direction of the dosing motion, and wherein the track has a second tab disposed therein with a free end configured for engaging the projection and for preventing rearward movement thereof from the ready position against the direction of the resetting motion.

6. The dispensing mechanism of claim 1, wherein the actuation mechanism comprises a driver rotatably associated with the housing and driven to rotate in a driving direction by the trigger during the dosing motion.

7. The dispensing mechanism of claim 6, wherein the driving direction is in an opposite rotational direction than a rotational spacing between the fired position and an adjacent ready position of the trigger, the driver being associated with the plunger rod for causing the plunger rod to eject said one of the doses.

8. The dispensing mechanism of claim 6, wherein:

one of the housing and trigger includes a first projection, and the other of the trigger and housing includes a first track, wherein the first track is configured for receiving the first projection and defines the dosing and resetting motions of the trigger with respect to the housing; and

one of the trigger and driver includes a second projection, and the other of the trigger and driver includes a second track, wherein the second track is configured for receiving the second projection, applying a force to the second projection during the dosing motion of the trigger to rotate the driver in the driving direction, and allowing the resetting motion of the trigger without rotating the driver.

9. The dispensing mechanism of claim 8, wherein the housing defines the first track and the trigger defines the first projection, and wherein the trigger defines the second track and the driver defines the second projection, wherein the first track defines a succession of a plurality of the ready positions interposed in continuous series by a plurality of the fired positions and paths for the corresponding dosing and resetting motions therebetween, and wherein the second track comprises a plurality of driving portions for causing the trigger to rotate the driver in each of the dosing motions connected in continuous series by alternately applying a force to the second projection during successive dosing motions of the trigger to rotate the driver in the driving direction.

10. The dispensing mechanism of claim 8, wherein the second track has a resetting portion aligned substantially axially to allow the resetting motion of the trigger without rotating the driver.

11. The dispensing mechanism of claim 6, wherein the driving direction is opposite from the direction of rotation of the trigger in the resetting motion.

12. An injector, comprising:

the dispensing mechanism of claim 1;

a cartridge associated with the housing and defining the medicament chamber;

a plunger disposed in the medicament chamber to seal the medicament therein, wherein the plunger rod is associated with the plunger for forcing the plunger in a distal direction for ejecting the doses; and

a needle in fluid communication with the medicament chamber configured for introducing the doses into a patient.

13. The dispensing mechanism of claim 1, wherein the volume of each of the successive doses of medicament is a fixed volume.

14. The dispensing mechanism of claim 1, wherein the volume of two or more doses of the successive doses of medicament are different.

15. The dispensing mechanism of claim 1, wherein the anti-retrograde mechanism includes a track and at least one tab.

16. The dispensing mechanism of claim 1, wherein the operational direction associated with the dosing motion includes a distal translation and the operational direction associated with the resetting motion includes a rotation and a proximal translation.

17. The dispensing mechanism of claim 1, wherein the medicament is a parathyroid hormone.

18. A dispensing mechanism configured to eject successive doses of a medicament from a medicament chamber, the dispensing mechanism comprising:

a housing;

a dosage adjuster configured to adjust a volume of each of the successive doses of medicament;

a plunger rod aligned along an axis, the plunger rod configured for ejecting the successive doses of medicament from the chamber;

an actuation mechanism that comprises a trigger associated with the housing and having a ready position and a fired position with respect to the housing, the trigger being configured for manipulation by a user for successive movement in;

a dosing motion from the ready position to the fired position generally in axial translation in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the successive doses of medicament, and

a resetting motion from the fired position to the ready position, wherein the trigger is uncoupled from the plunger rod during the resetting motion; and

an anti-retrograde mechanism associated with the actuation mechanism for preventing movement thereof against the direction of operation of the actuation mechanism through at least a portion of the dosing motion and the resetting motion;

wherein the anti-retrograde mechanism prevents the actuation mechanism from returning to the ready position associated with the dosing motion from the fired position associated with the dosing motion.

19. The dispensing mechanism of claim 18, wherein:

the actuation mechanism further comprises a driver rotatably associated with the housing and driven to rotate by the trigger during the dosing motion;

the driver is associated with the plunger rod and configured to cause the plunger rod to eject said one of the doses;

the anti-retrograde mechanism is configured for preventing rearward movement of the driver with respect to the trigger against the dosing motion;

one of the trigger and driver includes a projection; and

the other of the trigger and driver includes stepped surfaces facing a relative path of the projection during the dosing motion, the stepped surfaces configured for engaging the projection during rearward movement therebetween for preventing rearward movement of the trigger.

20. The dispensing mechanism of claim 19, wherein the stepped surfaces are substantially flat and face axially, and wherein the projection defines a notch to receive an edge of the stepped surfaces.

21. The dispensing mechanism of claim 19, wherein said other one of the trigger and driver comprising a sloped surface opposite the stepped surfaces and engaged with the projection during the dosing motion, the sloped surface configured to cause the trigger to cam the driver for rotating and driving the plunger rod.

22. The dispensing mechanism of claim 19, wherein the anti-retrograde mechanism is configured for preventing rearward movement of the driver with respect to the housing.

23. The dispensing mechanism of claim 19, wherein the anti-retrograde mechanism is configured for preventing rearward movement of the plunger rod.

24. The dispensing mechanism of claim 23, wherein the anti-retrograde mechanism is configured for preventing the rearward movement of the plunger rod only after a predetermined volume of medicament has been ejected from the medicament chamber and disabling the actuation mechanism by including a flexible arm disposed within the housing, the plunger rod being configured to force a portion of the flexible arm axially outwardly after the predetermined volume of medicament has been ejected from the chamber, and the flexible arm being configured to engage a portion of the trigger to prevent further motion of the trigger in the resetting motion to disable the actuation mechanism.

25. A method of dispensing a medicament from an injector having a dispensing mechanism configured to eject successive doses of a medicament from a medicament chamber, including

a housing;

a plunger rod aligned along an axis, the plunger rod configured for ejecting the successive doses of medicament from the chamber;

an actuation mechanism that comprises a trigger associated with the housing and having a ready position and a fired position with respect to the housing, the trigger being configured for manipulation by a user for successive movement in;

a dosing motion from the ready position to the fired position in which the trigger is associated with the plunger rod to cause the plunger rod to eject one of the successive doses of medicament, and

a resetting motion from the fired position to the ready position that comprises axial rotation of the actuation mechanism with respect to the housing, wherein the trigger is uncoupled from the plunger rod during the resetting motion; and

an anti-retrograde mechanism associated with the actuation mechanism and configured to prevent movement of the actuation member in a direction opposite to an operational direction associated with each of the dosing motion and the resetting motion;

wherein the anti-retrograde mechanism prevents the actuation mechanism from returning to the ready position associated with the dosing motion from the fired position associated with the dosing motion, the method comprising;

controlling or adjusting a volume of a dose of medicament; and

ejecting the dose of the medicament.