Needle assisted jet injector

A jet injection device comprising a housing;

• a nozzle assembly removably associated with the housing and defining a fluid chamber;
• a plunger movable in the fluid chamber of the nozzle assembly;
• a trigger assembly;
• a force generating source operatively associated with the trigger assembly such that movement of the trigger assembly activates the force generating source to move the plunger in a first direction to expel a fluid from the fluid chamber;
• and a fixed, non-retractable injection-assisting needle comprising a needle body fixed to and extending less than about 5 mm from a distal end of the nozzle assembly, and a discharge channel extending through the needle body, in fluid communication at a first end with the fluid chamber, and terminating at a second end in an orifice through which the fluid is expelled at a needle insertion point that is located at a needle tip of the needle, wherein the needle tip has a length sufficient to puncture the epidermis of a patient, and the force generating source provides a force of less than about 40 lbs for moving the plunger to expel the fluid through the needle tip and past the needle insertion point to an injection site that is substantially remote from the needle tip.

A method of delivering medicament by jet injection to an injection site in a patient comprising the steps of:

• inserting a needle into an insertion point by less than 5 mm and being operatively associated with an orifice in a nozzle assembly in fluid communication with an ampule chamber containing the medicament, the needle extending less than about 5 mm from the nozzle assembly orifice when the medicament is expelled;
• activating a force generating mechanism;
• and
• operatively associating a pressure wall member with the force generating member, with the pressure wall member being disposed and movable within the ampule chamber, so that the force generating member exerts a force of less than 40 lbs on the pressure wall member for moving the pressure wall member at a speed sufficient to jet inject the medicament from the ampule chamber through the orifice and needle to deliver a substantial portion of the medicament through the needle and past the insertion point to the injection site, wherein the needle insertion point is located at the needle tip and the needle injection site is substantially remote from the needle tip.

A jet injection device, comprising:

• a housing;
• a nozzle assembly associated with the housing to define a distal end, the nozzle assembly defining a fluid chamber configured for containing a fluid, and the nozzle assembly comprising an injection-assisting needle configured for penetrating an injection point up to the distal end, the needle defining a discharge channel in fluid communication with the fluid chamber and with a needle orifice of the needle, wherein the needle orifice is disposed beyond but less than about 5 mm from the distal end for delivering the fluid;
• a pressure wall associated with the fluid chamber for pressurizing the fluid therein;
• a trigger assembly operable by a user;
• and
• a force generating source associated with the trigger assembly such that the operation of the trigger assembly activates the force generating source for providing a force of less than about 40 lbs on the pressure wall to expel the fluid from the fluid chamber through the discharge channel to an injection site that is substantially remote from the orifice.

A method of delivering medicament by jet injection to an injection site in a patient comprising the steps of:

• inserting a needle into an insertion point, the needle being operatively associated with an orifice in a nozzle assembly in fluid communication with an ampule chamber containing the medicament, the needle having a needle orifice located at a distal end of the needle, the needle extending less than about 5 mm from the nozzle assembly orifice when the medicament is expelled;
• activating a force generating mechanism that is;
• and
• operatively associated with a pressure wall member, the pressure wall member being disposed and movable within the ampule chamber, so that the pressure wall member moves in response to the activation of the force generating mechanism at a speed sufficient to jet inject the medicament from the ampule chamber through the orifice and needle under a pressure of less than about 4000 psi to deliver a substantial portion of the medicament through the needle and past the insertion point to the injection site, wherein the needle insertion point is located at the needle tip and the needle injection site is substantially removed from the needle tip, and the needle tip is part of a retractable needle.