Needle assisted jet injector

• US 20020045866A1
• Filed: 02/09/2001
• Published: 04/18/2002
• Est. Priority Date: 08/11/1998
• Status: Active Grant

• Current Assignee: Antares Pharma Incorporated
• Original Assignee: Antares Pharma Incorporated
• Inventors: Lesch, Paul R. Jr., Holland, Margaret L., Berman, Claude L., Sadowski, Peter L., Deboer, David M.
• Granted Patent: US 6,746,429 B2
• Time in Patent Office: Days
• US Class Current: 604/208
• CPC Class Codes: A61M 2005/3247 Means to impede repositioning of protection sleeve from needle covering to needle uncovering position
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/002 Packages specially adapted therefor, e.g. for syringes or needles, kits for diabetics needle protection, e.g. caps, A61M5/3202; for sharps A61B50/3001
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• 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 5/2425 by compression of deformable ampoule or carpule wall
• CPC Class Codes: A61M 5/2466 by piercing without internal pressure increase A61M5/2429 takes precedence
• CPC Class Codes: A61M 5/282 by compression of deformable ampoule or carpule wall
• CPC Class Codes: A61M 5/288 by piercing without internal pressure increase A61M5/283 takes precedence
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• 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 5/3232 Semi-automatic needle retraction, i.e. in which triggering of the needle retraction requires a deliberate action by the user, e.g. manual release of spring-biased retraction means
• CPC Class Codes: A61M 5/3243 being axially-extensible, e.g. protective sleeves coaxially slidable on the syringe barrel devices for protecting guide needles in combination with catheters A61M25/0612
• CPC Class Codes: A61M 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
• CPC Class Codes: A61M 5/3286 Needle tip design, e.g. for improved penetration
• CPC Class Codes: A61M 5/349 using adhesive bond or glues

Abstract

A needle assisted jet injector and method for jet injecting medicament are disclosed. In one embodiment of the injector, the needle is retractably located within an injector nozzle assembly. Upon activation of the force generating source, a portion of the needle extends past the nozzle assembly and penetrates the outer layer of skin to deliver the medicament via jet injection to a deeper region. After activation, the needle retracts back into the nozzle assembly. In another embodiment, the needle is fixed to the end of the nozzle assembly. In both embodiments, the length of the portion of the needle that penetrates the skin is less than 5 mm.

Claims

1. A jet injection device comprising a housing, a retractable injection-assisting needle at a distal end of the injector, a nozzle assembly defining a fluid chamber, having an opening for slidingly receiving at least a portion of the needle and being removably associated with the housing, a plunger movable in the fluid chamber, a trigger assembly, and a force generating source operatively associated with the trigger assembly so that movement of the trigger assembly activates the energy source to move the plunger in a first direction to expel a fluid from the fluid chamber, said retractable injection-assisting needle comprising:

a needle tip located at a distal end of the needle with at least a portion configured and dimensioned to slide through the nozzle assembly opening;

a discharge channel within the needle tip and terminating in an orifice through which the fluid is expelled;

a body portion to direct fluid towards the discharge channel;

a plunger receptor configured and dimensioned to receive at least a portion of the plunger; and

a retraction element operatively associated with the needle and disposed substantially within the nozzle assembly;

wherein the needle is located within the nozzle assembly in a retracted position prior to activation of the force generating source;

movement of the plunger in the first direction upon activation of the energy source results in at least a portion of the needle tip extending beyond the nozzle assembly opening to a needle insertion point, and the fluid is expelled through the needle tip and past the needle insertion point to a needle injection site, the retraction element returns the needle tip to the retracted position after activation of the energy source, wherein the needle insertion point is located at the needle tip, and the needle injection site is distal to the needle tip.

2. The injection device of claim 1, wherein the retraction element is a resilient O-ring, a spring, or a flexible membrane which moves to allow extension of the needle tip beyond the nozzle assembly opening and then returns to its original position to return the needle tip to its retracted position.

3. The injection device of claim 1, wherein the needle body has an exterior surface which includes a ridge or recess for accommodating the retraction element.

4. The injection device of claim 1, wherein a shoulder is disposed between the needle tip and the needle body for accommodating the retraction element.

5. The injection device of claim 1, wherein the needle tip, when extended, has a length of approximately 1-5 mm.

6. A jet injection device comprising:

a housing having distal and proximal ends;

a fluid chamber having a seal at one end and located within said housing for holding at least about 0.02 ml to 3 ml of a medicament;

an injection-assisting needle having an injecting end and a piercing end and coupled to the distal end of said housing and moveable between a medicament storing position and a medicament delivering position wherein said needle is isolated from said fluid chamber when said needle is in said medicament storing position and said piercing end punctures the seal to provide a fluid pathway from the fluid chamber through the needle when said needle is in said medicament delivering position;

a plunger movable within the fluid chamber;

a force generating source capable of providing sufficient force on the plunger to eject an amount up to about 3 ml of the medicament from the fluid chamber in less than 2.75 seconds;

a needle guard located at the distal end of said housing for concealing said needle, the needle guard being moveable between a protecting position and an injecting position; and

an activation element operatively associated with the needle guard;

wherein the needle is located within the needle guard prior to activation of the force generating source so that retraction of the needle guard exposes the injecting end of said needle to an insertion point and activation of the force generating source moves the plunger to expel medicament from said fluid chamber and thereby eject the amount of the medicament through the injecting end of said needle and past the needle insertion point to an injection site in less than 2.75 seconds, the needle insertion point being located at the injecting end of the needle, and the injection site being distal to the injecting end of the needle.

7. The injection device of claim 6, wherein retraction of the needle guard from the protecting position to the injecting position activates the force generating source and the force generating source provides sufficient force to eject an amount of about 1 to 2 ml of the medicament in less than about 2.5 seconds.

8. The injection device of claim 7, further comprising a locking element associated with the needle guard for locking the needle guard in the protecting position after activation of the injection device and after return of said needle guard to the protecting position.

9. The injection device of claim 6, wherein the activation element comprises:

an inner housing located inside the housing and having trigger projections for maintaining the plunger in an idle position; and

a latch located inside the housing and circumferentially surrounding the inner housing, the latch being moveable between a firing position and an armed position;

wherein retraction of the needle guard to the injecting position urges the latch toward the firing position, thereby releasing the trigger projections from the plunger and activating the injection device.

10. The injection device of claim 6, further comprising an elastomeric element acting upon the needle guard and urging the needle guard toward the protecting position;

wherein the elastomeric element returns the needle guard to the protecting position after the medicament has been ejected from the needle, thereby substantially re-enclosing the needle.

11. The injection device of claim 6, wherein the needle is mounted on a needle holder operatively associated with the needle and the distal end of the housing, such that rotation of the needle holder places the needle in fluid communication with the fluid chamber.

12. The injection device of claim 6, further comprising a removable safety cap operatively associated with the distal end of the injection device such that rotation of the safety cap imparts rotation on the needle.

13. The injection device of claim 6, wherein the needle has a tip with a length of approximately 1-5 mm and the medicament is ejected at a at a pressure between around 100 to 1000 p.s.i. (689 to 6895 kPa) and at a rate of at least 0.40 ml/sec.

14. The injection device of claim 6,wherein at least a portion of the housing is made of a transparent or translucent material for allowing viewing of the fluid chamber, and the medicament is ejected at a pressure between around 100 to 500 p.s.i. (689 to 3448 kPa) and at a rate of about 0.50 ml/sec so that about 1 ml of the medicament is ejected in about 2 seconds.

15. The injection device of claim 6, wherein said fluid chamber comprises:

an ampule having a distal end, a proximal end and an opening in each of the distal and proximal ends;

a pierceable seal associated with the opening in the distal end;

a stopper located in the proximal end of the ampule for maintaining the medicament inside the ampule.

16. The injection device of claim 15, wherein activation of the force generating source moves the pierceable seal towards the injection assisting needle to pierce the seal and moves the stopper to eject medicament from the injection assisting needle.

18. The method of claim 17, further comprising the step of retracting the needle into the shield after the desired amount of medicament has been delivered to the injection site and wherein the applied force for ejecting the medicament is sufficient to eject an amount of about 1 to 2 ml of the medicament in less than about 2.5 seconds.

19. The method of claim 17, wherein pressing the shield against the injection site causes activation of the energy mechanism, and the medicament is ejected at a rate of about 0.50 ml/sec so that about 1 ml of the medicament is ejected in about 2 seconds.

20. The method of claim 17, wherein the needle has a length of approximately 1-5 mm and the medicament is ejected at a at a pressure between around 100 to 1000 p.s.i. and at a rate of at least 0.40 ml/sec.

21. The method of claim 17, wherein the medicament is ejected at a pressure between around 100 to 500 p.s.i. and at a rate of about 0.50 ml/sec so that about 1 ml of the medicament is ejected in about 2 seconds.

17. A method of delivering medicament to an injection site of a patient, comprising the steps of:

extending a needle from a shield prior to inserting the needle into the needle insertion point, said shield initially concealing the needle;

inserting the needle into the needle insertion point to a depth of less than 5 mm, with the needle being in fluid communication with a fluid chamber that contains at least about 0.02 to 2 ml of the medicament; and

applying a force sufficient to eject the medicament from the fluid chamber and through the needle to deliver the medicament to the injection site in less than about 2.75 seconds, wherein the needle insertion point is located more superficial than the injection site.