Needle assemblies for wet/dry automatic injectors

• US 8,568,367 B2
• Filed: 01/26/2007
• Issued: 10/29/2013
• Est. Priority Date: 10/10/2000
• Status: Active Grant

• Current Assignee: Meridian Medical Technologies Incorporated
• Original Assignee: Meridian Medical Technologies Incorporated
• Inventors: Griffiths, Steven M., Hill, Robert L.
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): GILBERT, ANDREW M
• Application Number:
  US11/698,937
• Publication Number:
  US 20070123818A1
• Time in Patent Office: 2,468 Days
• Field of Search: 604/82, 604 85- 89, 604/92, 604/134, 604/135, 604/190, 604/191, 604240-243
• US Class Current: 604/240
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 2005/287 by displacing occluding plugs
• CPC Class Codes: A61M 2005/3106 Plugs for syringes without needle
• CPC Class Codes: A61M 2005/3131 specially adapted for improving sealing or sliding
• CPC Class Codes: A61M 2005/3132 having flow passages for injection agents at the distal end of the barrel to bypass a sealing stopper after its displacement to this end due to internal pressure increase
• CPC Class Codes: A61M 2202/064 Powder
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2205/7545 for solid matter, e.g. microaggregates
• CPC Class Codes: A61M 5/19 having more than one chamber , e.g. including a manifold coupling two parallelly aligned syringes through separate channels to a common discharge assembly surgical glue applicators A61B17/00491
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/2066 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/284 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/286 upon internal pressure increase, e.g. pierced or burst A61M5/283 takes precedence
• CPC Class Codes: A61M 5/3145 Filters incorporated in syringes
• CPC Class Codes: A61M 5/31513 Piston constructions to improve sealing or sliding
• CPC Class Codes: A61M 5/31596 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: A61M 5/3293 characterised by features of the needle hub
• CPC Class Codes: A61M 5/34 Constructions for connecting the needle , e.g. to syringe nozzle or needle hub connecting catheter tubes to hubs A61M25/0014
• CPC Class Codes: A61M 5/343 : Connection of needle cannula to needle hub, or directly to syringe nozzle without a needle hub A61M5/322 takes precedence
• CPC Class Codes: A61M 5/348 : snap lock, i.e. upon axial displacement of needle assembly A61M5/344 takes precedence

Abstract

An automatic medicament injector having a compartment for a dry medicament component and a compartment for a wet medicament component. The two compartments are separated by a seal structure that converts from a sealing condition to a mixing condition when the device is activated. The seal structure includes a wiper that scrapes the interior walls in the dry component compartment to prevent the dry component from accumulating at the seal/glass interface. A tapered insert funnels the mixed medicament components to an attached needle assembly, but can be removed when the device is filled. A filter is provided between the medicament compartments and the needle assembly. A chamber between the filter and the needle allows for better flow through the filter. An actuation assembly drives the seal structure into the mixing condition and forces the mixed medicament through the needle and into the user.

Claims

1. An automatic injection device containing a pre-loaded charge of medicament for automatically self-administering the medicament upon actuation thereof, the device comprising:

a housing;

a medicament chamber disposed in the housing, the medicament chamber including a first compartment containing a first medicament portion, and a second compartment containing a second medicament portion to be mixed with the first medicament portion;

a seal structure between the first compartment and the second compartment, the seal structure being initially in a sealing condition that maintains the first compartment separate from the second compartment, the seal structure being converted to a mixing condition as a result of activation of the device;

a needle assembly that dispenses the medicament charge from the medicament chamber; and

an activation assembly disposed in the housing and including a stored energy source, wherein activation of the activation assembly releases the stored energy from the stored energy source, causing the seal structure to be converted from the sealing condition to the mixing condition, and thereby causing or allowing the first and second medicament portions to be mixed and forced through the needle assembly;

wherein the needle assembly comprises a needle and a needle support for mounting the needle to the medicament chamber, the needle support defining a needle assembly chamber having a rearward opening in fluid communication with the medicament chamber, the rearward opening has the smallest diameter opening through which fluid flows from the medicament chamber to the rearward opening, the needle assembly chamber having an inner surface tapering radially inward as it extends axially forward towards a rearward end of the needle, the needle support having a passageway connecting the needle assembly chamber to the needle and having a diameter narrower than the outside diameter of the needle, the inner surface of the needle assembly chamber having a diameter at the connection to the passageway that equals the diameter of the passageway.

2. The automatic injection device of claim 1 wherein no rearward portion of the needle protrudes into the needle assembly chamber.

3. The automatic injection device of claim 2 wherein the needle assembly chamber has a substantially hemisphetical shape.

4. The automatic injection device of claim 1 further comprising a fluid distributing member carried by the seal structure.

5. The automatic injection device of claim 1 wherein the seal structure comprises an outer seal structure carrying a wiper portion, a flow path formed in the outer seal structure, and a plug member for sealing the flow path when the seal structure is in the sealing condition, the wiper portion extending axially and forwardly from the outer seal structure.

6. The automatic injection device of claim 5 wherein the seal structure has an outer periphery that forms a peripheral seal with an interior wall of the medicament chamber, and wherein said plug member is spaced radially inward from the peripheral seal that seals the at least one flow path formed in the seal structure.

7. The automatic injection device of claim 6 wherein the first medicament portion comprises a dry medicament portion and the wiper portion carried by the outer seal structure is configured to direct dry medicament particles engaged with the walls of the medicament chamber radially inward as the seal structure is moved through the first compartment.