Drug delivery mechanism

Patent metadata

Field	Value
Publication number	US-11766519-B2
Application number	US-201916961762-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 17, 2018
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A flexible plunger rod, drug delivery mechanism, drug delivery device, and methods are described that utilize the flexible plunger rod perform drug delivery operations. In embodiments, the flexible plunger rod can be stored in a curved configuration to thereby reduce a footprint of the drug delivery mechanism and device.

First claim

What is claimed is:

1. A delivery assembly for a drug delivery device, the delivery assembly comprising:
a reservoir having a tubular housing extending along a longitudinal axis and having a delivery opening at a distal end;
a plunger disposed within the reservoir in engagement with the housing;
a flexible plunger rod comprising a spring having a predetermined preload amount and being operably coupled to the plunger; and
a feeding mechanism coupled to the flexible plunger rod and configured to drive the flexible plunger rod along the longitudinal axis of the housing to drive the plunger towards the distal end, the feeding mechanism including a drive gear assembly having a central opening for the spring to extend therethrough, the central opening including a thread configured to engage the spring such that rotation of the drive gear assembly relative to the spring causes the spring to move longitudinally through the drive gear assembly,
wherein the thread includes a shim that is configured to extend between adjacent coils of the spring.

2. The delivery assembly of claim 1 , further comprising a plunger rod housing portion having a curved sidewall configured to bend the flexible plunger rod in a storage configuration.

3. The delivery assembly of claim 1 , wherein a coil member of the spring has a circular or rectangular cross section.

4. The delivery assembly of claim 1 , wherein the thread comprises a threaded cavity configured to engage coils of the spring.

5. The delivery assembly of claim 1 , wherein the feeding mechanism further comprises a motor having a driveshaft operably coupled to the drive gear assembly, and further comprising a controller configured to maintain a generally constant injection speed by controlling the operation of the motor.

6. The delivery assembly of claim 1 , further comprising a coupling member mounted to a distal end of the flexible plunger rod, the coupling member and plunger having cooperating structures configured to engage one another and prevent rotation of the flexible plunger rod relative to the plunger.

7. The delivery assembly of claim 1 , wherein a distal end of the flexible plunger rod is fixed to the plunger.

8. The delivery assembly of claim 1 , further comprising a stabilizer member extending within the flexible plunger rod and coupled thereto, the stabilizer member having an elongate body with a flat configuration to control flexing of the flexible plunger rod.

9. A drug delivery device including the delivery assembly of claim 1 .

10. The drug delivery device of claim 9 , further comprising an insertion assembly including a cannula selectively fluidly connected to the reservoir.

11. The drug delivery device of claim 9 comprising an on-body or an autoinjector drug delivery device.

12. A method for dispensing a drug, the method comprising:
driving a flexible plunger rod, comprising a spring having a predetermined preload amount, through a central opening of a drive gear assembly, the central opening including a thread configured to engage the spring such that driving the flexible plunger rod includes rotating the drive gear assembly relative to the spring to cause the spring to move longitudinally through the drive gear assembly, wherein the thread includes a shim that is configured to extend between adjacent coils of the spring; and
driving a plunger longitudinally within a reservoir containing a drug with the flexible plunger rod.

13. The method of claim 12 , further comprising coupling the flexible plunger rod and the plunger with a coupling member, the coupling member and plunger having cooperating structures such that, with the coupling member mounted to a distal end of the flexible plunger rod, the flexible plunger rod and plunger are restricted from rotating with respect to one another.

14. The method of claim 12 , further comprising storing the flexible plunger rod in a curved configuration.

15. The method of claim 12 , further comprising preloading the flexible plunger rod a predetermined amount.

16. The method of claim 12 , further comprising controlling operation of a motor having a driveshaft operably coupled to the drive gear assembly to maintain generally constant rotation of the drive gear assembly and thereby maintain generally constant movement of the plunger and flexible plunger rod through the reservoir.

Assignees

• Amgen Inc

Inventors

• Dutta Ray Sudeshna
• Gibson Scott R
• Groszmann Daniel Eduardo
• Mojarrad Mehran
• Dees Robert Allen
• Johnson Jonathan Dean
• Murcia Antonio S

Classifications

• A61M5/31583

  based on rotational translation, i.e. movement of piston rod is caused by relative rotation between the user activated actuator and the piston rod · CPC title

• A61M5/2033

  Spring-loaded one-shot injectors with or without automatic needle insertion (multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287) · CPC title

• A61M5/31511 Primary

  Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence) · CPC title

• A61M5/14248 Primary

  of the skin patch type · CPC title

• A61M5/1452

  pressurised by means of pistons · CPC title