Claims for Patent: 8,376,993

Summary for Patent: 8,376,993

Title:	Multiple dosage injector
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.
Inventor(s):	Cox; Janice L. (St. Paul, MN), Rust; Matthew (Hudson, WI), KraMer; Thomas E. (Coon Rapids, MN), Hoeft; Peter (Lindstrom, MN)
Assignee:	Antares Pharma, Inc. (Ewing, NJ)
Application Number:	12/536,106
Patent Claims:	1. A medicament dispensing mechanism configured to eject successive doses of the medicament from a medicament chamber, comprising: a housing; a plunger rod configured for ejecting the doses of medicament from the chamber; and an actuation mechanism that comprises a trigger associated with the housing and having a ready position and a fired position with respect thereto, 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 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; 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 the rotational spacing between the fired position and 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. The dispensing mechanism of claim 1, wherein the predetermined volume includes a fixed volume. 13. The dispensing mechanism of claim 1, wherein the anti-retrograde mechanism includes a track and at least one tab. 14. 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. 15. The dispensing mechanism of claim 1, wherein the medicament is a parathyroid hormone. 16. An injector, comprising: the dispensing mechanism of claim 1; a cartridge associated with the housing and defining the chamber; a plunger disposed in the 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 chamber for injecting the doses into a patient. 17. A medicament dispensing mechanism configured to eject successive doses of the medicament from a medicament chamber, comprising: a housing; a plunger rod configured for ejecting the doses of medicament from the chamber; an actuation mechanism that comprises a trigger associated with the housing and having a ready and a fired position with respect thereto, the trigger being configured for manipulation by a user for successive movement in: a dosing motion from the ready position to the fired position, during the dosing motion the trigger being associated with the plunger rod to cause the plunger rod to eject one of the doses; 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. 18. The dispensing mechanism of claim 17, wherein: the actuation mechanism 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 for causing 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. 19. The dispensing mechanism of claim 18, 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. 20. The dispensing mechanism of claim 18, 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 to cause the trigger to cam the driver for rotating and driving the plunger rod. 21. The dispensing mechanism of claim 18, wherein the anti-retrograde mechanism is configured for preventing rearward movement of the driver with respect to the housing. 22. The dispensing mechanism of claim 18, wherein the anti-retrograde mechanism is configured for preventing rearward movement of the plunger rod. 23. The dispensing mechanism of claim 22, wherein the anti-retrograde mechanism is configured for preventing the rearward movement of the plunger rod only after a predetermined number of doses have been ejected from the 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 number of doses have 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.

Details for Patent 8,376,993

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Nps Pharmaceuticals, Inc.	NATPARA	parathyroid hormone	For Injection	125511	01/23/2015		2028-08-05