Claims for Patent: RE44847

Summary for Patent: RE44847

Title:	Needle assisted jet injector
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.
Inventor(s):	Sadowski; Peter L. (Woodbury, MN), Deboer; David M. (Grand Rapids, MI), Berman; Claude L. (Effingham, NH), Lesch, Jr.; Paul R. (Lino Lakes, MN), Holland; Margaret L. (New Haven, CT)
Assignee:	Antares Pharma, Inc. (Ewing, NJ)
Application Number:	13/530,974
Patent Claims:	1. A method of operating a needle-assisted jet-injection device with a proximal and a distal end, the distal end having a movable needle guard concealing a needle with an axial opening through which fluid is ejected, the method comprising the steps of: applying the distal end of the injection device to an injection site so as to gently urge the needle guard to move proximally thereby inserting the needle into the injection site and causing a force-providing mechanism to pressurize a medicament-containing fluid chamber within the jet injection device, wherein the needle is inserted into the injection site to a depth less than 5 mm, wherein the fluid chamber holds from about 0.02 to about 3 ml of a medicament-containing fluid, and wherein the fluid-chamber pressure is sufficient to eject the fluid-chamber contents through the needle in less than about 2.75 seconds as a fluid jet so as to penetrate a certain distance into tissue at the injection site beyond the distal end of the needle. 2. The method of claim 1 wherein fluid communication between the needle and the fluid chamber is provided by twisting the needle guard. 3. The method of claim 1 wherein fluid communication between the needle and the fluid chamber is provided by motion of a distal stopper in the fluid chamber so as to penetrate a proximal end of the needle, the motion caused by the pressurized fluid. 4. The method of claim 1 further comprising the step of retracting the needle into the needle guard after the desired amount of medicament has been delivered into the injection site. 5. The method of claim 1 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. 6. The method of claim 1 further comprising providing fluid communication between the distal tip of the needle and the fluid chamber prior to the step of applying. 7. The method of claim 6 wherein the injection site is subcutaneous and the needle insertion point is at a depth of between about 1 mm and 5 mm. 8. The method of claim 6 wherein the needle insertion point is at a depth of up to about 3 mm. 9. The method of claim 6 wherein the medicament is injected at a rate of at least about 0.40 ml/sec. 10. The method of claim 6 wherein the medicament is injected to the injection site in less than about 2.75 seconds. 11. The method of claim 6 wherein the medicament is injected at a rate so that about 1 ml of the medicament is ejected in about 2 seconds. 12. The method of claim 6 further including applying an injecting pressure to the medicament that is no greater than about 500 p.s.i. 13. The method of claim 6 further including applying an injecting pressure to the medicament that reaches between about 150 and 375 p.s.i. 14. The method of claim 6 wherein the axial opening of the needle distal tip has a diameter of about between about 0.004 to 0.012 inches. 15. The method of claim 6 wherein the needle is a 26 to 27 gage needle. 16. The method of claim 6 wherein the needle comprises: an injecting end portion, including the distal end, that is inserted into the patient to the needle insertion point; and a proximal portion that has common axial cross-sectional dimensions as the injecting end portion and extends proximally into an injection device housing member in which the fluid chamber is disposed during the ejection of the medicament, the proximal portion being longer than the injecting end portion. 17. The method of claim 16 wherein the proximal and injecting end portions have substantially common and continuous inner and outer diameters. 18. The method of claim 17 wherein the needle has a length of about 1-5 mm. 19. The method of claim 6 wherein the needle is extended by a distance of about 1-5 mm from an injection device housing member that houses the fluid chamber. 20. The method of claim 6 wherein the fluid chamber is made of glass. 21. The method of claim 6 wherein the pressure is applied such that the injection site is deeper than the needle insertion point. 22. A method of operating a needle-assisted jet-injection device with a proximal and a distal end, the distal end having a movable needle guard concealing a needle with an axial opening through which fluid is ejected, the method comprising the steps of: providing fluid communication between the distal tip of the needle and a medicament-containing fluid chamber within the jet injection device; and applying the distal end of the injection device to an injection site so as to gently urge the needle guard to move proximally thereby inserting the needle into the injection site and causing a force-providing mechanism to pressurize the fluid chamber to a pressure from around 100 but no more than around 1000 p.s.i., wherein the needle is inserted into the injection site to a depth less than 5 mm, wherein the fluid chamber holds from about 0.02 to about 3 ml of a medicament-containing fluid, and wherein the fluid-chamber pressure is sufficient to eject the fluid-chamber contents through the needle in less than about 2.75 seconds as a fluid jet so as to penetrate a certain distance into tissue at the injection site beyond the distal end of the needle. 23. A method of delivering medicament to an injection site of a patient by operating a needle-assisted jet-injection device with a proximal and a distal end, the distal end concealing a needle with an axial opening through which fluid is ejected, the method comprising the steps of: providing fluid communication between the distal tip of the needle and a medicament-containing fluid chamber within the jet injection device; and extending a needle having a length of approximately 1-5 mm from the distal end of the device for inserting the needle into the skin of the patient such that the distal end of the needle reaches a needle insertion point having a depth of less than 5 mm below the surface of the patient's skin, with the fluid chamber containing at least about 0.02 to 3 ml of the medicament, the needle distal end having an axial opening for ejection of the fluid; and causing a force-providing mechanism to pressurize the fluid chamber to a pressure from around 100 but no more than around 1000 p.s.i. to eject the medicament from the fluid chamber and through the inserted needle by jet injection to create a high-speed jet of the medicament that penetrates patient tissue to the injection site located beyond the needle insertion point and to deliver up to about 3 ml of the medicament to the injection site in less than about 2.75 seconds, wherein the needle insertion point is located more superficially than the injection site; wherein the medicament is ejected at a rate of at least 0.40 ml/sec through the axial opening of the needle distal end to the injection site. .Iadd.24. A method of operating an injection device containing a medicament-containing fluid chamber, said injector device having a distal and a proximal end, and a needle guard a portion of which is located within the distal end of the injection device, said needle guard having an extended position and a retracted position, and an injecting needle having an axial opening, said method comprising the steps of: applying the distal end of the injection device to an injection site so as to gently urge the needle guard to move proximally further into the distal end of the injection device to the retracted position thereby activating a stored energy generating mechanical member to pressurize the medicament-containing fluid chamber and to eject the medicament from the injecting needle into the injection site; removing the distal end of the injection device from the injection site, wherein the needle guard moves from the retracted position to the extended position; and wherein the pressure in the medicament-containing fluid chamber is sufficient to eject the medicament through the injecting needle at a rate of at least 0.02 ml in 2.75 seconds..Iaddend. .Iadd.25. The method according to claim 24, wherein the medicament is ejected from the axial opening of the needle..Iaddend. .Iadd.26. The method according to claim 24, wherein the injection needle is inserted into the injection site..Iaddend. .Iadd.27. The method according to claim 24, further comprising the step of viewing the medicament within the fluid chamber to determine the status of the injection device..Iaddend. .Iadd.28. The method according to claim 24, further comprising the step of removing a safety cap from the distal end of the injector device prior to applying the distal end of the injection device to the injection site..Iaddend. .Iadd.29. The method according to claim 24, further comprising the step of depressing a push button after the distal end of the injection device is applied to the injection site..Iaddend. .Iadd.30. A method of operating an injection device containing a medicament-containing fluid chamber, said injector device having a distal and a proximal end, a push button located at the proximal end and a needle guard a portion of which is located within the distal end of the injection device, said needle guard having an extended position and a retracted position, and an injecting needle having an axial opening, said method comprising the steps of: applying the distal end of the injection device to an injection site so as to gently urge the needle guard to move proximally further into the distal end of the injection device to the retracted position; depressing the push button to thereby pressurize the medicament-containing fluid chamber so to eject the medicament from the needle; removing the distal end of the injection device from the injection site, wherein the needle guard moves from the retracted position to the extended position; and wherein the fluid chamber pressure is sufficient to eject the medicament through the injecting needle at a rate of at least 0.02 ml in 2.75 seconds..Iaddend. .Iadd.31. The method according to claim 30, wherein the medicament is ejected from the axial opening of the needle..Iaddend. .Iadd.32. The method according to claim 30, wherein the injection needle is inserted into the injection site..Iaddend. .Iadd.33. The method according to claim 30, further comprising the step of viewing the medicament within the fluid chamber to determine the status of the injection device..Iaddend. .Iadd.34. The method according to claim 30, further comprising the step of removing a safety cap from the distal end of the injector device prior to applying the distal end of the injection device to the injection site..Iaddend.