Mixing and Dosing System

Abstract

The injection system includes an injection system body defining a proximal opening at a proximal end thereof and a distal needle interface at a distal end thereof. The system also includes a proximal stopper member and a distal stopper member disposed within the injection system body, forming a proximal drug chamber between the proximal stopper member and the distal stopper member, and forming a distal drug chamber between the distal stopper member and the distal end of the injection system body. The system further includes a plunger member configured to be manually manipulated to insert the proximal stopper member relative to the injection system body. Additionally, the system includes a valve forming an openable barrier between the distal needle interface and at least a portion of the distal drug chamber. The valve is configured to permit flow from a portion of the distal drug chamber to the distal needle interface upon an increase in pressure in the distal drug chamber.

Description

[Technical field]

[0001] The present disclosure relates generally to injection systems, devices and processes for facilitating various levels of control over fluid injection, and more particularly to systems and methods relating to multi-chamber injection systems, with or without safety features, in medical environments. [Background technology]

[0002] Millions of syringes, such as that shown in FIG. 1A (2), are consumed daily in medical settings. A typical syringe (2) includes a tubular body (4), a plunger (6), and an injection needle (8). As shown in FIG. 1B, such syringes (2) can be utilized not only to inject fluids into a patient, but also to withdraw fluids from or expel fluids into a container, such as a vial, bag, or other drug containment system (10). In fact, in some countries, such as the United States, concerns regarding maintaining sterility and regulatory constraints dictate that if a syringe (2) is used with a vial (10) as shown in a particular patient environment, such vial must be used for only one patient and then disposed of, resulting in a lot of medical waste from the waste of the vial and the remaining drug, and also contributing to periodic shortages of certain important drugs. Referring to FIG. 2A, three luer type syringes (12) are shown, each having a distally disposed luer fitting configuration (14) for mating with other devices having a similar fitting configuration, such as the luer manifold assembly (16) shown in FIG. 2B. The luer manifold assembly of FIG. 2B can be used to administer liquid medications intravenously to a patient with or without the use of an intravenous infusion bag. The luer fitting (14) of the syringe in FIG. 2A is sometimes referred to as a "male" luer fitting, and the luer fitting (18) of FIG. 2B is sometimes referred to as a "female" luer fitting, with one of the luer interfaces being threaded (in which case the configuration may be referred to as a "luer lock" configuration) to couple the two through relative rotation, which may also be combined with a compressive load. In other words, in one embodiment of a luer lock, rotation, possibly along with compression, is utilized to engage threads on the male fitting (14), which are configured to engage a flange on the female fitting (18) to bring the device into a fluid-tight bond. In another embodiment, a tapered interface shape may be utilized to provide luer engagement using compression, without threads or rotation (such a configuration may be referred to as a "slip-on" or "conical" luer configuration).Although such luer connections are perceived as relatively safe for the operator, there is a risk of spilling or leaking the drug or of parts breaking during assembly of the luer connection. On the other hand, the use of needle injection configurations poses a risk of the sharp needle contacting or stabbing a person or unwanted structures. For these reasons, so-called "safety syringes" have been developed.

[0003] One embodiment of a safety syringe (20) is shown in FIG. 3, in which a tubular shield member (22) is spring-biased to cover the needle (8) when released from a locked position relative to the syringe body (4). Another embodiment of a safety syringe (24) is shown in FIG. 4A and FIG. 4B. In this configuration, a retractable needle (26) is configured to retract (28, 26) to a safe position within the tubular body (4) as shown in FIG. 4B after the plunger (6) is fully inserted relative to the syringe body (4). Such a self-contained configuration may be associated with issues of blood splatter / aerosolization, safe storage of preloaded energy that may malfunction and actuate too early, loss of precision in delivering a full dose injection due to residual dead space within the spring compression volume, and / or loss of retraction speed control that may be associated with pain or patient anxiety.

[0004] The syringe market has become more complex due to the increasing demand for pre-filled syringe assemblies such as those shown in Figures 5A and 5B, which generally comprise a syringe body or "drug containment and delivery system" (34), a plunger tip, plug or stopper (36), and a distal seal or cap (35) attached to a luer interface (Figure 5A shows the cap 35 in place, while Figure 5B has the cap removed to illustrate the luer interface 14). The liquid drug resides in a volume or drug reservoir (40) between the distal seal and the distal end (37) of the plunger tip (36). The plunger tip (36) may comprise a standard butyl rubber material, coated with a biocompatible lubricious coating (e.g., polytetrafluoroethylene ("PTFE") or the like to facilitate favorable sealing and relative motion characteristics relative to the associated syringe body structure and material. The proximal end of the syringe body (34) in FIG. 5B comprises a conventional one-piece syringe flange (38) that is integrally formed with the material of the syringe body (34). The flange (38) is configured to extend radially from the syringe body (34) and is configured to be fully or partially circumferential around the syringe body (34). A partial flange is known as a "clipped flange" and is formed such that the other flange is not clipped to the syringe body (34). The flange is known as a "full flange." The flange is used to grip the syringe with the fingers and provides support for depressing the plunger to effect an injection. The syringe body (34) preferably comprises a translucent material, such as glass or a polymer. A plunger tip (36) may be disposed within the syringe body (34) to form a contained volume within the chamber or reservoir (40) and aid in the evacuation of the associated fluid through the needle. The syringe body (34) may define a generally cylindrical shape (i.e., such that a plunger tip 36 having a circular cross-sectional shape establishes a seal against the syringe body (34)) or may be configured to have other cross-sectional shapes, such as an elliptical shape.

[0005] Such assemblies are desirable because they can be standardized and precisely mass-produced by the few manufacturers in the world who can afford to meet all of the world's ever-changing regulations regarding filling, packaging, and drug / drug interfacing material selection and component use. However, such simple configurations generally cannot meet new global standards for single-use, safety, auto-disable, and needlestick protection. For this reason, certain suppliers have moved to more "vertical" solutions that attempt to meet all or at least part of the standards in one solution, such as those shown in Figure 5C (41), and as a result of trying to meet those standards in many different scenarios, such products have significant limitations (including those discussed above with reference to Figures 3-4B) and can have relatively high inventory and usage costs.

[0006] In some cases, multi-component infusion systems may mix infusion components (e.g., liquids and / or powders) prior to injection. Some systems utilize a single infusion device to draw liquid components from one container and inject the liquid components into another container to dissolve dry components therein. The dissolved dry components are then drawn into the infusion device for injection into the patient. Such systems require frequent handling of exposed needles and unnecessarily expose the user to one or more uncovered needles. Also, manually transferring liquid components from one container to another container may result in incomplete transfer of liquid components, affecting the ratio of components in the final mixed infusate. Additionally, accessing and manipulating multiple component containers complicates the injection process and increases the risk of user error. Thus, a need exists for a multi-component infusion system that simplifies the manual accessing and mixing of multiple components from multiple containers.

[0007] These limitations are addressed by multi-chamber injection systems configured to mix and inject multiple components. However, there remains a need for precisely controlled multi-chamber injection systems for precise handling, mixing and delivery of multi-component infusates.

[0008] Additionally, many injection fluids (eg, pharmaceuticals) have the added requirement of minimizing the time that the injection fluid is exposed to metal (eg, the stainless steel of a needle).

[0009] It is also desirable to incorporate anti-needle stick technology into the injection system: the ability to at least partially retract the sharp end of the needle within the syringe protects the injector and the patient from inadvertent needle stick injuries.

[0010] There is a need for an injection system that addresses the shortcomings of currently available configurations, particularly a need for a multi-chambered safety injection solution with precise control that can utilize the existing relatively well-controlled supply chain of conventionally sourced pre-filled syringe assemblies, such as those described with reference to Figures 5A and 5B. Summary of the Invention

[0011] Embodiments are directed to infusion systems, and more particularly, to a safe, multiple chamber infusion system that provides precise control over the handling, mixing and delivery of multi-component infusates.

[0012] In one embodiment, the injection system includes an injection system body defining a proximal opening at a proximal end thereof and a distal needle interface at a distal end thereof. The system also includes a proximal stopper member and a distal stopper member disposed within the injection system body, forming a proximal drug chamber between the proximal stopper member and the distal stopper member, and forming a distal drug chamber between the distal stopper member and the distal end of the injection system body. The system further includes a plunger member configured to be manually manipulated to insert the proximal stopper member relative to the injection system body. Additionally, the system includes a valve forming an openable barrier between the distal needle interface and at least a portion of the distal drug chamber. The valve is configured to permit flow from a portion of the distal drug chamber to the distal needle interface upon an increase in pressure in the distal drug chamber.

[0013] In one or more embodiments, the system also includes an elongated fluid transfer member, and the valve is configured to stabilize the elongated fluid transfer member within the distal drug chamber. The valve can define a central opening and can include a central seal. The fluid transfer member can be configured to pass through the central opening, and the central seal can be configured to form a fluid-tight seal against an outer longitudinal surface of the fluid transfer member. The valve can define a distally facing funnel configured to guide a proximal end of the fluid transfer member through the central seal during assembly of the injection system. The valve can define a distally facing peripheral wall configured to provide a space between the valve and the distal end of the injection system body.

[0014] In one or more embodiments, the valve includes a circumferential gasket configured to form a fluid-tight seal with an inner surface of the infusion system body within the distal medication chamber. The circumferential gasket can be made of a resilient material. The resilient material can be any of rubber, thermoplastic elastomer, butyl rubber, or polyisoprene elastomer. The circumferential gasket can be configured to couple the valve to an inner surface of the infusion system body. The valve can include a port configured to be opened by an increase in pressure in the distal medication chamber.

[0015] In one or more embodiments, the valve includes a rigid portion and an elastic portion. The rigid portion can be made of a cyclic olefin copolymer. The elastic portion can be made of rubber, a thermoplastic elastomer, a butyl rubber, or a polyisoprene elastomer. The elastic portion can include an annular flap configured to be disposed adjacent a distal surface of the rigid portion and a circumferential gasket extending from a periphery of the annular flap. The circumferential gasket can be configured to form a fluid-tight seal with an inner surface of the infusion system body within the distal drug chamber.

[0016] In one or more embodiments, the rigid portion can include an annular portion. The annular portion can define a port extending therethrough, and the port can be configured to be removably sealed by an annular flap of the resilient portion. The annular flap of the resilient portion can be configured such that the annular flap is biased to removably seal the port. An increase in pressure in the distal drug chamber can cause the annular flap to move away from the port defined by the annular portion of the rigid portion, thereby unsealing the port. The annular portion can define a raised annular wall surrounding the port, the annular wall extending distally from a distal face of the annular portion. The annular portion can define a distally extending dome. The rigid portion can include a distally extending portion coupled to the annular portion. The distally extending portion can be configured to interact with a distal needle interface to provide a space between the valve and a distal end of the infusion system body.

[0017] In one or more embodiments, the distally extending portion is configured to interact with the distal needle interface to couple the valve to the injection system body such that a distal surface of a circumferential gasket of the valve contacts the distal end of the injection system body. The circumferential gasket can be configured to form a fluid-tight seal with an inner surface of the distal end of the injection system body. The circumferential gasket can have an outer periphery that is smaller than an inner periphery of the injection system body. The distally extending portion can be configured to interact with the distal needle interface to provide a space between the valve and the distal end of the injection system body.

[0018] In another embodiment, an injection system includes an injection system body defining a proximal opening at a proximal end thereof and a distal needle interface at a distal end thereof. The system also includes a proximal stopper member and a distal stopper member disposed within the injection system body, forming a proximal drug chamber between the proximal stopper member and the distal stopper member, and forming a distal drug chamber between the distal stopper member and the distal end of the injection system body. The system further includes a plunger member configured to be manually manipulated to insert the proximal stopper member relative to the injection system body. Additionally, the system includes an elongated fluid transfer member configured to at least partially extend through the proximal stopper member to form a flow path from the distal drug chamber to the proximal drug chamber, the elongated fluid transfer member defining a circumferential shoulder. Additionally, the system includes an insert configured to be disposed in the proximal stopper member. The insert includes a distally facing funnel and a pair of fingers configured to engage a circumferential shoulder of the elongate fluid transfer member to temporarily prevent distal movement of the proximal stop member relative to the elongate fluid transfer member while a flow path is open from the distal drug chamber to the proximal drug chamber.

[0019] In one or more embodiments, the funnel is made from a cyclic olefin copolymer. The pair of fingers can be made from a metal, such as annealed stainless steel. The pair of fingers and the circumferential shoulder can be configured such that an increase in a distally directed force applied to the plunger member after the proximal drug chamber is fully collapsed overcomes the engagement between the pair of fingers and the circumferential shoulder, allowing distal movement of the proximal stopper member relative to the elongated fluid transfer member. The circumferential shoulder can have a larger diameter than the remainder of the elongated fluid transfer member.

[0020] The above and other embodiments of the present invention are described in the following detailed description. [Brief description of the drawings]

[0021] The patent or application file contains at least one color drawing. Copies of this patent or patent application publication with color drawing(s) will be provided by the U.S. Patent and Trademark Office upon request and payment of the necessary fee. [Figure 1] 1A and 1B show various aspects of a conventional injection syringe configuration. [Diagram 2] 2A and 2B show various aspects of a conventional injection syringe configuration. [Diagram 3] FIG. 3 illustrates various aspects of a conventional injection syringe configuration. [Figure 4] 4A and 4B show various aspects of a conventional injection syringe configuration. [Diagram 5] 5A-5C show various aspects of conventional injection syringe configurations. [Figure 6] 6A and 6B are perspective and longitudinal cross-sectional views illustrating various aspects of a syringe-based dual chamber safety injection system that allows the distal needle end / tip to be retracted into a protective configuration after use, according to some embodiments. [Figure 7] 7A-7P are side and longitudinal cross-sectional views illustrating various aspects of a syringe-based dual chamber safety injection system during steps of a method of mixing and injecting using the system according to some embodiments. [Figure 8] FIG. 8 is a perspective view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 9] FIG. 9 is a detailed perspective view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 10] FIG. 10 is a detailed perspective view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 11] FIG. 11 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 12]FIG. 12 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 13] FIG. 13 is an exploded view of a valve for use in a dual chamber injection system according to some embodiments. [Figure 14] FIG. 14 is a perspective view of a valve for use in a dual chamber injection system according to some embodiments. [Figure 15] FIG. 15 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 16] FIG. 16 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 17] FIG. 17 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 18] FIG. 18 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system according to some embodiments. [Figure 19] FIG. 19 is a detailed perspective view illustrating various aspects of a syringe-based dual chamber safety injection system in which the distal needle end / tip retracts into a protective configuration after use, according to some embodiments. [Figure 20] FIG. 20 is a detailed perspective view illustrating various aspects of a syringe-based dual chamber safety injection system in which the distal needle end / tip retracts into a protective configuration after use, according to some embodiments. [Figure 21] FIG. 21 is a detailed perspective view illustrating various aspects of a syringe-based dual chamber safety injection system in which the distal needle end / tip retracts into a protective configuration after use, according to some embodiments. [Figure 22] FIG. 22 is a detailed longitudinal cross-sectional view illustrating various aspects of a syringe-based dual chamber safety injection system in which the distal needle end / tip retracts into a protective configuration after use, according to some embodiments. [Figure 23] FIG. 23 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system with a metal insert according to some embodiments. [Figure 24] FIG. 24 is a detailed cross-sectional view illustrating various aspects of a syringe-based dual chamber injection system with a metal insert according to some embodiments. [Diagram 25] FIG. 25 illustrates various aspects of a syringe-based dual chamber injection system with a metal insert according to some embodiments.

[0022] In order to better understand how the above and other advantages and objects of the various embodiments can be obtained, a more detailed description of the embodiments is provided with reference to the accompanying drawings. It should be noted that the drawings are not drawn to scale and that elements of similar structure or function are designated with similar reference numerals throughout. It should be understood that the drawings depict only certain exemplary embodiments and therefore should not be considered as limiting the scope of the embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Exemplary Prefilled Dual Chamber Safety Infusion System Exemplary Dual Chamber Safety Injection System 6A and 6B, there are shown perspective and longitudinal cross-sectional views of a dual chamber safety injection system having a prior art commercially available pre-filled syringe body (34) with prior art proximal and distal stopper members (32, 36) disposed therein. The proximal and distal stopper members (32, 36) together with the syringe body (34) define proximal and distal drug chambers (40, 42). The proximal and distal stopper members (36, 37) occlude the proximal and distal ends of the proximal drug chamber (40). The distal stopper member (36) occludes the proximal end of the distal drug chamber (42). A needle coupling assembly (606) is disposed at the distal end of the distal drug chamber (42) and has a needle cover member (63) attached for storage. The dual chamber safety injection system controls the transfer of the first drug component from the proximal drug chamber (40) to the distal drug chamber (42) and the expulsion of the mixed / combined drug in a distal direction from the distal drug chamber (42) by the user sequentially inserting the plunger member (44) into the syringe body (34) to various degrees. The plunger member (44) includes a proximal stopper member (32), a plunger housing member (69) and a plunger operation interface (128). The first drug component (252) located in the proximal drug chamber (40) may be a liquid, such as an aqueous or oil-based drug solution, a gel, or the first drug component may be a diluent for mixing with the second drug component (254) in the distal drug chamber (42). The second drug component (254) in the distal drug chamber (42) may be a drug in a dry form, such as a powder, microspheres, emulsion, lyophilized drug or solid drug in a solid form.

[0024] The dual chamber safety injection system has a fixed needle configuration in which, when provided to a user, the needle assembly including the needle coupling assembly (606), needle distal / tip (48), needle binding member and needle proximal end (50) is ready for injection after removal of the needle cover member (63) that includes an elastomeric sealing material on its inner surface for interacting with the needle distal end (48) or the distal housing portion (610) during storage. Alternatively, the needle cover member (63) may include a vent (not shown) to allow pressure due to transfer and mixing of the drug components to escape from the interior of the syringe body (34) while preventing ingress of contamination into the syringe body (34). Although the fixed needle is shown as being fixed in place, the fixed needle may be removably coupled to the syringe body (34) using a luer type interface (not shown) with the proximal end (50) of the needle member extending into the distal drug chamber (42) through the luer type interface. In the embodiment shown in Figures 6A-7P, the majority of the safety needle retraction hardware resides within the plunger housing (69).

[0025] The dual chamber safety injection system (100) has a fixed needle configuration in which, when provided to a user, the needle assembly including the needle spine assembly ("needle") (76) and the needle coupling assembly (606) is ready for injection after removal of the needle cover member (63) which includes an elastomeric sealing material on its inner surface for interacting with the needle distal end (78) and / or the distal housing portion during storage. Alternatively, the needle cover member (63) may include a vent (not shown) that allows pressure caused by transfer of the first drug component / diluent (252) to escape from the interior of the syringe body (34) while preventing ingress of contamination into the syringe body (34). Although the fixed needle is shown as being fixed in place, the fixed needle may be removably coupled to the syringe body (34) using a luer slip or luer lock interface (not shown) with the proximal end (50) of the needle member extending into the distal chamber (42) via the luer interface. Alternatively, the needle may be fixedly or removably attached to a flange on the cartridge body instead of to the syringe. In the embodiment shown in Figures 6A and 6B, most of the safe needle retraction hardware resides within the plunger housing (69).

[0026] 7A-7P, various embodiments of configurations designed to facilitate multi-part medicament injection and needle retraction into a syringe body are shown, where two or more medicament components are mixed to form an injection mixture or solution immediately prior to delivery into a patient's body. In one embodiment, a liquid first medicament component / diluent (252) can be combined with a substantially non-liquid second medicament component (254), such as a powder form of a drug, such as a lyophilized medicament component, immediately prior to injection. The configurations described herein with reference to FIGS. 7A-7P relate to dual chamber configurations, where two or more chambers within the same syringe body (34) are utilized to transport, mix and inject the injection solution.

[0027] 7A and 7B, the proximal and distal medicament chambers (40, 42) are formed by a distal stopper member (36) between two portions of the interior of the syringe body (34), the distal medicament chamber (42) contains an air or gas gap as well as a non-liquid medicament (254), and the proximal medicament chamber (40), opposite the distal stopper member (36), contains a liquid diluent (252) that is proximally contained by the proximal stopper member (32). The liquid diluent (252) is a first component of the medicament, and the non-liquid medicament (254) is a second component of the medicament.

[0028] Referring to FIG. 7C and the associated cross-sectional view of FIG. 7D, various components of the needle coupling assembly are shown (here, a so-called “fixed” needle coupling assembly (606) is shown, although other needle assemblies, as described below, including luer couplings as well as fixed configurations, can be utilized). The lug feature (258) is configured to aid in coupling the needle coupling assembly (606) to the needle cover member (63), as shown, for example, in FIG. 7A. A small O-ring can be utilized as a sealing member (260) around the needle shaft, and a large O-ring can be utilized as a sealing member (262) at the syringe body (34) / needle coupling assembly (606) interface. Alternatively, the small O-ring (260) and the large O-ring (262) can be combined into a single seal that performs both O-ring sealing functions. Also, the small O-ring (260) can be used to both seal around the needle shaft and to the syringe body (34).

[0029] The needle includes multiple (e.g., four) proximal openings / ports (270) configured to allow entry of liquid diluent that exits from a more distally located intermediate opening / opening (266), and a lumen plug (268) occludes the needle lumen to create a flow path from the proximal opening (270) to the intermediate opening (266) under circumstances such as those described above with reference to Figures 6N and 7H. The needle also includes a distal opening (264) opposite the lumen plug (268) from the intermediate opening (266). The distal opening (264) is fluidly coupled through the needle to the needle distal end (48) for injecting liquid into the patient.

[0030] Referring to Figure 7E, a proximal harpoon interface (84) is configured to pierce the proximal and distal stop members (32, 36) in series and mate with a coupling feature of the plunger member (44) (e.g., needle retaining feature-like element (712) shown, for example, in Figures 7N and 7P). Figure 7F shows a spike-style harpoon coupling interface (85) configured to pierce both the proximal and distal stop members (32, 36) in series and mate with a coupling feature of the plunger member (44) to retract the needle member at least partially into the plunger member (44) after an injection has been administered to the patient.

[0031] Figures 7A, 7B, and 7G-7P show a sequence of actions for an injection procedure utilizing a dual chamber safety injection system as described above. With reference to Figures 7A and 7B, the injection assembly is in a stable configuration that can be shipped or carried into an injection patient care scenario, with a first drug component / liquid diluent (252) separated from a second non-liquid drug component (254), each located on either side of the distal stopper member (36) within the syringe body.

[0032] 7G and 7H illustrate the initial insertion movement of the plunger member (44), which advances the distal (36) and proximal (32) stopper members together relative to the syringe body (34). As shown in FIG. 7H, when the proximal end (50) of the needle assembly is advanced sufficiently to penetrate the distal stopper member (36), a fluid pathway is formed between the two pre-isolated chambers (40, 42) of the syringe body (34), such that the liquid first drug component (252) in the proximal drug chamber (40) flows through the transfer pipe (46), into at least one of the proximal openings (270), and out the more distal intermediate opening (266) to reach the non-liquid second drug component (254) in the distal drug chamber (42).

[0033] Figures 7I and 7J show that further insertion of the stopper members (36, 32) until they are immediately adjacent one another causes the liquid first drug component / diluent (252) to move into the distal drug chamber (42) where it merges with the non-liquid second drug component (254). Figures 7K and 7L show that over time and / or manual agitation, the liquid first drug component / diluent (252) and the formerly non-liquid second drug component (254) mix to form a mixed drug solution (272).

[0034] In some embodiments, particularly for lyophilized, non-liquid second drug components, the mixed drug solution (272) may be formed with minimal or no agitation or over time. In other embodiments, particularly for drugs held in suspension or emulsified drugs, vigorous shaking may be required to promote mixing. When shaking vigorously, it is useful for the user to be able to remove his thumb from the plunger operating interface (128). During transfer of the liquid first drug component (252) from the proximal drug chamber (40) to the distal drug chamber (42), pressure may build up in the distal drug chamber (42). This pressure acts on the proximal and distal stopper members (32, 36) to resist stopper movement. The increased pressure may also cause the stopper members (32, 36) and plunger operating interface (128) to move in a proximal direction if the user is not restraining the plunger member (44) with his thumb. A mixing configuration latch or "mix click" on the plunger member (44) can be utilized to provide resistance to movement of the plunger operating interface (128) due to pressure build-up and to allow the user to remove their thumb from the plunger operating interface (128) for shaking or mixing the medicament. The mix click can also provide an audible and / or tactile indication that transfer of the liquid first medicament component (252) is complete. The distal medicament chamber (42) can also include an agitation device to aid in mixing of the medicament components.

[0035] When the assembly is ready to inject the mixed solution (272), the exposed needle distal end (48) can be injected into the patient by removing the needle cover member (63) and depressing / inserting the plunger member (44) and associated stopper members (36, 32), as shown in Figures 7M and 7N. As shown in Figures 7O and 7P, full depression / insertion of the plunger member (44) and associated stopper members (32, 36) can automatically retract the sharp needle distal end / tip (48) at least partially through the distal and proximal stopper members (36, 32) to a safe position within either the syringe body (34), the needle coupling assembly (606), or at least partially within the plunger member (44). Automatic retraction of the needle may occur at least partially within the plunger.

[0036] Exemplary dual chamber injection system with filter FIG. 8 illustrates a dual chamber injection system (800) having a valve (820) disposed therein, according to some embodiments. Similar to the dual chamber injection system illustrated in FIGS. 6A-7P, the dual chamber injection system (800) includes an injection system body (34), proximal and distal stop members (32, 36), a plunger member (44), and an elongated fluid transfer member (50). The proximal and distal stop members (32, 36) together with the injection system body (34) form proximal and distal medicament chambers (40, 42), as described above. The proximal and distal medicament chambers (40, 42) are pre-filled with a liquid first medicament component and a non-liquid second medicament component (not shown for clarity; see 252, 254 in FIGS. 6A and 6B).

[0037] The injection system body (34) includes a distal needle interface (810) at its distal end. In some embodiments, the distal needle interface (810) may be a female luer connector. The distal needle interface (810) may define a number of small spaces. If the non-liquid second drug component migrates into some of the small spaces in the distal needle interface (810), the non-liquid second drug component may block those small spaces and prevent the liquid from exiting the injection system body (34). The non-liquid second drug component in those small spaces may not dissolve, which may change the final concentration of the drug in the mixed drug.

[0038] The valve (820) can perform one, two, three or all of the four functions described below. First, the valve (820) can minimize and / or eliminate migration of the non-liquid second drug component into the distal needle interface (810) during assembly and storage of the injection system (800). Second, the valve (820) can center and stabilize the elongated fluid transfer member (50), thereby facilitating piercing of the distal stopper member (36) by the elongated fluid transfer member (50). Third, the valve (820) can minimize and / or eliminate drug loss during shaking and mixing with vented injection. Fourth, in a vented infusion system (800) in which the distal needle interface (810) is open to the atmosphere to allow air to escape during fluid transfer from the proximal chamber (40) to the distal chamber (42), the valve (820) can prevent loss of the mixed drug from the opening of the distal needle interface (810) during shaking and mixing of the drug components. This fourth function prevents drug loss and protects the environment from toxic drugs. These valve functions, particularly the third and fourth functions, ensure that the drug components in the proximal and distal chambers (40, 42) are thoroughly mixed before the mixed drug is discharged distally through the distal needle interface (810) and out of the infusion system body (34) (e.g., into either a medication bag or a needle).

[0039] As shown in Figure 9, when the valve (820) is open after mixing and pressurizing the distal chamber (42), a fluid flow path (822) is available through the valve (820). The valve (820) may be configured to open after the proximal medicament chamber (40) has collapsed and the liquid first medicament component (252) has been transferred into the distal medicament chamber (42) (see Figures 7I and 7J). At that point, the liquid first medicament component (252) and the non-liquid second medicament component (254) have been mixed, and the mixed medicament is ready to be expelled from the infusion system body (34) for delivery to the patient.

[0040] 10 illustrates in greater detail a dual chamber injection system (800) having a valve (820) disposed therein, according to some embodiments. The valve (820) defines a pair of ports (832) configured to be biased to a closed configuration to minimize and / or prevent the passage of a non-liquid second medicament component. The ports (832) are also configured to change to an open configuration upon increased pressure (e.g., greater than atmospheric pressure) in the distal medicament chamber (42) to allow a liquid (e.g., mixed medicament) to pass therethrough.

[0041] The valve (820) also defines a circumferential gasket (842) configured to form a fluid-tight seal with the inner circumferential surface (34.1) of the infusion system body (34). The fluid-tight seal provided by the gasket (842) is combined with a closed configuration in which the pair of ports (832) are biased to minimize and / or prevent migration of the non-liquid second drug component through the valve (820) and into the distal needle interface (810).

[0042] In the embodiment shown in Figure 10, the valve (820) is restrained from distal movement relative to the injection system body (34) by engagement with the distal end of the injection system body (34). The valve (820) also defines a distally extending member (834) configured to center and / or stabilize the elongate fluid transfer member (50).

[0043] Figure 11 illustrates a detailed longitudinal cross-sectional view of a dual chamber infusion system (800) having a valve (820) disposed therein in a closed configuration, according to some embodiments. The valve (820) includes a rigid member (830) and a resilient member (840), as shown in Figure 13. The rigid member (830) can be fabricated (e.g., molded) from a cyclic olefin copolymer. The rigid member (830) defines a pair of ports (832), a distally extending member (834), and an annular portion (836).

[0044] The resilient member (840) may be fabricated (e.g., molded) from a variety of resilient materials, such as rubber, thermoplastic elastomer, butyl rubber, or polyisoprene elastomer. The resilient member (840) defines a circumferential gasket (842) and an annular flap (844). The circumferential gasket (842) extends from an outer periphery of the annular flap (844) such that the resilient member (840) wraps around the annular portion (836) of the rigid member (830). The circumferential gasket (842) is configured to form a fluid-tight seal with the circumferential inner surface (34.1) of the infusion system body (34). The annular flap (844) of the resilient member (840) is biased to seal / close the pair of ports (832) of the rigid member (830).

[0045] The port (832) is also configured to change to an open configuration that allows liquid (e.g., mixed medication) to pass therethrough when pressure in the distal medication chamber (42) increases (e.g., becomes greater than atmospheric pressure).

[0046] The circumferential gasket (842) is also configured to exert a frictional force against the circumferential inner surface (34.1) of the injection system body (34) to couple the valve (820) to the injection system body (34). As a result, interference between the distally extending member (834) of the rigid member (830) and the distal needle interface (810) is no longer necessary to couple the valve (820) to the injection system body (34). The circumferential gasket (842) coupling the valve (820) to the injection system body (34) allows for a greater tolerance in the distal needle interface (810) and the distally extending member (834). Furthermore, in such an embodiment, the valve (820) can align the distally extending member (834) approximately in the center of the injection system body (34). The distally extending member (834) can prevent the valve (820) from moving too distally within the injection system body (34) and thereby provide space (828) for the valve (820) to open, as described herein.

[0047] FIG. 12 illustrates a detailed longitudinal cross-sectional view of a dual chamber infusion system (800) having a valve (820) disposed therein in an open configuration, according to some embodiments. The valve (820) is in the open configuration due to an increase in pressure (e.g., above atmospheric pressure) in the distal medication chamber (42). The increase in pressure forces the annular flap (844) away from the distal face of the annular portion (836) of the rigid member (830). This opens a fluid flow path (822) through the valve (820). The fluid flow path (822) originates from the distal medication chamber (42), passes through at least one of the pair of ports (832), along the space (824) between the annular flap (844) and the annular portion (836) of the rigid member (830), and distally exits through a central opening (846) defined by the annular flap (844) of the resilient member (840). Thus, when pressure increases in the distal drug chamber (42), the space (824) between the annular flap (844) and the annular portion (836) of the rigid member (830) opens, opening a fluid flow path (822) through the valve (820).

[0048] The amount of pressure required to open valve (820) can be adjusted / tuned by varying various features of valve (820), including but not limited to the size of port (832), the contact force of annular flap (844) on port (832), and the contact stress of annular flap (844) against port (832). In the embodiment of valve (820) shown in FIG. 13, annular portion (836) of rigid member (830) forms a distally facing dome to increase the contact force and contact stress of annular flap (844) against port (832).

[0049] 14 illustrates a rigid member (830') of some embodiments of a valve (820). The rigid member (830') defines a raised annular wall (838) extending distally from around each port (832). The raised annular wall (838) increases the contact stress between the annular flap (844) and the sharp wall edge adjacent the port (832), thereby increasing the pressure required within the distal drug chamber (42) to open the valve (820).

[0050] Figures 15 and 17 show detailed longitudinal cross-sectional views of a dual chamber infusion system (1500) having a valve (1520) disposed therein in a closed configuration, according to some embodiments. The valve (1520) includes a rigid member (1530) and a resilient member (1540). The rigid member (1530) defines a pair of ports (1532), a distally extending member (1534), and an annular portion (1536). Figure 16 shows the valve (1520) prior to being fully inserted into the distal needle interface (1510) of the infusion system body (34).

[0051] The resilient member (1540) defines a circumferential gasket (1542) and an annular flap (1544). The circumferential gasket (1542) extends from an outer periphery of the annular flap (1544) such that the resilient member (1540) wraps around the annular portion (1536) of the rigid member (1530). The circumferential gasket (1542) is configured to form a fluid-tight seal with the distal inner surface (34.2) of the infusion system body (34). The annular flap (1544) of the resilient member (1540) is biased to seal / close the pair of ports (1532) of the rigid member (1530).

[0052] The port (1532) is also configured to change to an open configuration when pressure in the distal drug chamber (42) increases (e.g., becomes greater than atmospheric pressure) to allow liquid (e.g., mixed drugs) to pass therethrough.

[0053] The distally extending member (1534) of the rigid member (1530) is configured to form an interference fit with the distal needle interface (1510) to couple the valve (1520) to the infusion system body (34). Using an interference fit between the distally extending member (1534) and the distal needle interface (1510) to couple the valve (1520) to the infusion system body (34) allows a single valve (1520) to be used with multiple infusion system bodies having various diameters. When pressure in the distal drug chamber (42) increases (e.g., exceeds atmospheric pressure), the annular flap (1544) is displaced from the distal face of the annular portion (1536) of the rigid member (1530). This opens a fluid flow path (not shown) through the valve (1520), as shown in the related embodiment in FIG. 12.

[0054] In the embodiment shown in Figures 15-17, the valve 1520 is precisely positioned relative to the injection system body 34 by an interference fit between the distal needle interface 1510 and the distal extending member 1534 that couples the valve 1520 to the injection system body 34. The distal extending member 1534 prevents the valve 1520 from moving too far distally within the injection system body 34, thereby providing space 1528, see Figure 17, for the valve 1520 to open, as described herein. Figure 18 shows the valve 1520' having moved too far distally within the injection system body 34. As a result, the space 1528' is insufficient for the valve 1520' to open.

[0055] 19-22 illustrate a dual chamber infusion system (1900) having a valve (1920) disposed therein, according to some embodiments. FIGS. 19, 20, and 22 illustrate the valve (1920) in a biased closed configuration. FIG. 21 illustrates the valve (1920) in an open configuration. The valve (1920) includes a rigid member (1930) and a resilient member (1940). The rigid member (1930) defines a pair of ports (1932) and an annular portion (1936). The resilient member (1940) defines a circumferential gasket (1942) and an annular flap (1944). The circumferential gasket (1942) extends from an outer periphery of the annular flap (1944) such that the resilient member (1940) wraps around the annular portion (1936) of the rigid member (1930). The circumferential gasket (1942) is configured to form a fluid-tight seal with the inner circumferential surface (34.1) of the injection system body (34).

[0056] The annular flaps (1944) of the resilient member (1940) are biased to seal / close a pair of ports (1932) in the rigid member (1930), which are also configured to change to an open configuration upon an increase in pressure in the distal medication chamber (42) (e.g., greater than atmospheric pressure) to open a flow passage (1922; see FIG. 21 ) that allows fluid (e.g., mixed medication) to pass through the valve (1920).

[0057] Circumferential gasket (1942) is also configured to exert a frictional force against an inner circumferential surface (34.1) of infusion system body (34) to couple valve (1920) to infusion system body (34). Resilient member (1940) also defines a distally facing annular bump (1948; see FIG. 22) configured to provide sufficient space (1928) for valve (1920) to open.

[0058] The valve (1920) shown in Figures 19-22 is configured for use with a safety injection system in which the fluid transfer member (50) is retractable into the injection system body (34) such that a sharp distal end (not shown) of a needle fluidly coupled to the fluid transfer member (50) is safely disposed within the injection system body (34) as shown in Figures 7O and 7P. To this end, the valve (1920) includes a central seal (1950; see Figure 22) configured to form a fluid-tight seal against an outer longitudinal surface of the fluid transfer member (50). The fluid-tight seal between the central seal (1950) and the fluid transfer member (50) is a light interference fit that allows the fluid transfer member (50) to be retracted through the central seal (1950) during retraction while minimizing or preventing material from passing therethrough. The central seal (1950) also includes a distally facing funnel (1952) configured to guide the proximal end of the fluid transfer member (50) into the central seal (1950) during assembly.

[0059] Exemplary bushing with insert in dual chamber injection system 23-25 ​​illustrate a prefilled dual chamber safety injection system (2300) according to some embodiments. The system (2300) includes a stop bushing (2310) having an insert (2312) disposed therein (see FIGS. 23 and 24). The insert (2312) includes a pair of fingers (2314) configured to interact with a shoulder (2352) formed on a fluid transfer member (2350) to provide resistance to distal movement of a distal stop member (2336) relative to the fluid transfer member (2350) (see FIG. 24).

[0060] Interaction between fingers (2314) and shoulder (2352) of insert (2312) maintains distal stop member (2336) in a transfer position during transfer of the liquid first drug component from proximal drug chamber (40) to distal drug chamber (42). This interaction allows the user to apply a greater range of forces to the plunger member to transfer liquid while minimizing the risk of premature movement of distal stop member (36).

[0061] FIG. 23 illustrates a distal stopper member (36) having a stopper bushing (2310) with an insert (2312) and defining an alignment funnel (2316). The alignment funnel (2316) is configured to guide a proximal end of a fluid transfer member (2350) into the insert (2312). FIG. 23 illustrates a storage / transport configuration of the system (2300). In this configuration, a pointed proximal end (2354) of the fluid transfer member (2350) is disposed adjacent to and partially within the insert (2312). Various characteristics (e.g., geometry, material, etc.) of the proximal end (2354) and the insert (2312) can be altered to adjust the force required to push the proximal end (2354) through the distal stopper member (2336). In some embodiments, the force required to push the proximal end (2354) through the distal stop member (2336) is between about 2 pounds and about 5 pounds, which allows for storage of the prefilled dual chamber system (2300) while minimizing the risk of premature movement of the distal stop member (2336), which could render the system (2300) unusable.

[0062] FIG. 24 illustrates the transfer configuration of the system (2300). In this configuration, a user-applied force on the plunger member pushes the distal stop member (2336) distally past the pointed proximal end (2354) of the fluid transfer member (2350). The proximal end of the groove (2656) of the fluid transfer member (2350) is disposed within the proximal drug chamber (40), thereby allowing liquid to transfer from the proximal drug chamber (40) to the distal drug chamber (42). In this configuration, the shoulder (2352) of the fluid transfer member (2350) is disposed adjacent to the finger (2314) of the insert (2312). Various characteristics of the shoulder (2352) and the insert (2312) (e.g., geometry, material, etc.) can be altered to adjust the force required to push the shoulder (2352) past the finger (2314) of the insert (2312). In some embodiments, the force required to push the shoulder (2352) past the insert (2312) is between about 2 pounds and about 5 pounds. Pressure applied to the plunger member while the system (2300) is held in the transfer configuration shown in FIG. 24 due to the interaction between the shoulder (2352) and the insert (2312) aids in the transfer of liquid from the proximal drug chamber (40) to the distal drug chamber (42). The force required to overcome the interference between the shoulder (2352) and the insert (2312) allows the user more freedom to push the plunger member to aid in the transfer of liquid. This increases the likelihood that the liquid will be completely transferred.

[0063] The shoulder (2352) has a larger diameter than the portion of the fluid transfer member (2350) distal to the shoulder (2352). As a result, as the fingers (2314) of the insert (2312) move distally over the shoulder (2352), the fingers (2314) do not experience significant friction against the fluid transfer member (2350). Additionally, the metal-to-metal interaction of the fingers (2314) with the fluid transfer member (2350) is more repeatable and produces fewer particles. In some embodiments, the insert (2312) is formed from a material that has some elasticity (e.g., annealed stainless steel) to further minimize the forces on the fluid transfer member (2350) after it passes over the shoulder (2352).

[0064] The preset force magnitude can be adjusted to correspond to a combination of system functional requirements and aesthetic impression for the user. If the actuation force is too low, it will actuate but the user may have difficulty applying a light enough force, which may lead to the user overdoing it. On the other hand, if the force is too high, the user may find the system "too hard" to actuate. Fortunately, the range of preset force magnitudes can be "tuned" by modifying the properties of various components.

[0065] Although the above-described embodiments include a dual chamber safety injection system, other multi-chamber safety injection systems are also within the scope of the claims. For a multi-chamber safety injection system having three or more chambers, three or more stopper members can be inserted into the injection system body (e.g., syringe body, cartridge body, etc.) to define a corresponding number of chambers.

[0066] The prefilled dual chamber safety injection system disclosed and described herein includes a syringe with a fixed needle, however, the various configurations / embodiments described herein (e.g., continuous injection, detent dual chamber, threaded plunger member, shielded and vented needle cover) can be used with cartridges, autoinjectors, and needleless injection systems having luer connectors, transfer piping.

[0067] Various exemplary embodiments of the present invention are described herein. These examples are referred to in a non-limiting sense. They are provided to illustrate the broader applicable aspects of the present invention. Various modifications can be made to the described invention and equivalents can be substituted without departing from the true spirit and scope of the invention. In addition, many modifications can be made to adapt a particular situation, material, composition of matter, process, process acts or steps to the objective, spirit or scope of the present invention. Moreover, as will be understood by those skilled in the art, each of the individual variations described and exemplified herein has individual components and features that can be easily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. All such modifications are intended to be within the scope of the claims associated with this disclosure.

[0068] Any of the described devices for performing a subject diagnostic or interventional procedure may be provided in a packaged combination for use in performing such an intervention. These supply "kits" may further include instructions for use and may be packaged in a sterile tray or container as commonly employed for such purposes.

[0069] The present invention includes methods that may be performed with a subject device. The methods may include the act of providing such a suitable device. Such providing may be performed by an end user. That is, the act of "providing" merely requires the end user to obtain, access, approach, place, set up, activate, power on or take other actions to provide the required device in the subject method. Methods described herein may carry out the recited events in any order that is logically possible or in the sequence of events recited.

[0070] Exemplary embodiments of the present invention, together with details regarding material selection and manufacture, have been described above. As for other details of the present invention, they may be understood in conjunction with the patents and publications cited above, as well as generally known or understood by those skilled in the art. For example, those skilled in the art will understand that one or more lubricious coatings (e.g., hydrophilic polymers such as polyvinylpyrrolidone-based compositions, fluoropolymers such as tetrafluoroethylene, PTFE, ETFE, hydrophilic gels, or silicones) may be used in conjunction with various parts of the device, such as relatively large interfaces of movably connected parts, as needed, to facilitate, for example, low-friction manipulation or advancement of such objects relative to other parts of the instrument or nearby tissue structures. The same will be true for method-based embodiments of the present invention with respect to additional actions that are generally or logically taken.

[0071] Furthermore, although embodiments have been described with reference to several examples optionally incorporating various features, the present invention is not limited to those described or disclosed as contemplated for each variation of the present invention. Various modifications can be made to the present disclosure as described, and equivalents (whether described herein or not included for brevity) can be substituted without departing from the true spirit and scope of the present invention. Furthermore, when a range of values ​​is provided, it is to be understood that all intervening values ​​between the upper and lower limits of the range, as well as other stated or intervening values ​​within the stated range, are encompassed within the scope of the present invention.

[0072] It is also contemplated that any feature of the described inventive variation may be described and claimed independently or in combination with any one or more of the features described herein. Reference to a singular item includes the possibility of a plurality of the same items. More specifically, as used in this specification and the claims appended hereto, the singular forms "a," "an," "said," and "the" include plural referents unless otherwise indicated. In other words, the use of articles allows for "at least one" of the subject items in the above description, as well as the claims appended hereto. It is noted that such claims may be drafted to exclude optional elements. Thus, this statement is intended to function as a preceding statement using exclusive terms such as "solely," "only," and the like in connection with the recitation of claim elements, or a preceding statement to use a "negative" limitation.

[0073] Without using such exclusive language, the term "comprising" in any claim appended to this disclosure shall be construed as allowing for the inclusion of any additional elements, regardless of whether a given number of elements are recited in such claim or whether the addition of features would be considered to change the nature of the elements recited in such claim. Except as specifically defined herein, all technical and scientific terms used herein shall be given the broadest possible and commonly understood meaning while maintaining the validity of the claims.

[0074] The breadth of the present invention is not to be limited by the examples and / or subject specification provided, but rather is to be limited only by the scope of the language of the claims appended to this disclosure.

Claims

1. 1. An injection system comprising: an injection system body defining a proximal opening at a proximal end thereof and a distal needle interface at a distal end thereof; a proximal stop member and a distal stop member disposed within the injection system body, the proximal stop member and the distal stop member forming a proximal drug chamber therebetween and a distal stop member and a distal drug chamber between the distal stop member and a distal end of the injection system body; a plunger member configured to be manually manipulated to insert the proximal stopper member into the injection system body; a valve forming an openable barrier between the distal needle interface and at least a portion of the distal medication chamber; 11. An injection system, comprising: a valve configured to permit flow from a portion of the distal drug chamber to the distal needle interface upon an increase in pressure in the distal drug chamber.

2. 2. The system of claim 1, further comprising an elongated fluid transfer member; The system, wherein the valve is configured to stabilize the elongate fluid transfer member within the distal medication chamber.

3. 3. The system of claim 2, the valve defines a central opening and includes a central seal; the fluid transfer member is configured to pass through the central opening; The system, wherein the central seal is configured to form a fluid-tight seal against an outer longitudinal surface of the fluid transfer member.

4. 4. The system of claim 3, The valve defines a distally facing funnel configured to guide a proximal end of the fluid transfer member through the central seal during assembly of the injection system.

5. 4. The system of claim 3, The system, wherein the valve defines a distally facing peripheral wall configured to provide a space between the valve and a distal end of the injection system body.

6. 2. The system of claim 1, The system, wherein the valve comprises a circumferential gasket configured to form a fluid-tight seal with an inner surface of the injection system body within the distal medication chamber.

7. 7. The system of claim 6, The system wherein the circumferential gasket is made from a resilient material.

8. 8. The system of claim 7, The system, wherein the elastic material is rubber, a thermoplastic elastomer, a butyl rubber, or a polyisoprene elastomer.

9. 7. The system of claim 6, The system, wherein the circumferential gasket is configured to couple the valve to an inner surface of the injection system body.

10. 2. The system of claim 1, The system, wherein the valve includes a port configured to be opened by an increase in pressure in the distal medication chamber.

11. 2. The system of claim 1, The system wherein the valve comprises a rigid portion and a resilient portion.

12. 12. The system of claim 11, The system, wherein the rigid segment is made from a cyclic olefin copolymer.

13. 12. The system of claim 11, The system, wherein the elastic portion is made from rubber, a thermoplastic elastomer, a butyl rubber, or a polyisoprene elastomer.

14. 12. The system of claim 11, The elastic portion is an annular flap configured to be disposed adjacent a distal surface of the rigid portion; a circumferential gasket extending from an outer periphery of the annular flap; The system, wherein the circumferential gasket is configured to form a fluid-tight seal with an interior surface of the injection system body within the distal medication chamber.

15. 15. The system of claim 14, the rigid portion comprises an annular portion; the annular portion defining a port extending therethrough; The system, wherein the port is sealed by an annular flap of the elastic portion, which is configured to be removable.

16. 16. The system of claim 15, an annular flap of the resilient portion is biased to removably seal the port; The system is characterized in that the annular flap is configured such that an increase in pressure in the distal drug chamber causes the annular flap to move away from a port defined by the annular portion of the rigid portion, thereby unsealing the port.

17. 16. The system of claim 15, The annular portion defines a raised annular wall surrounding the port, the annular wall extending distally from a distal surface of the annular portion.

18. 16. The system of claim 15, The system wherein the annular portion defines a distally extending dome.

19. 12. The system of claim 11, The system, wherein the rigid portion includes a distally extending portion coupled to an annular portion.

20. 20. The system of claim 19, the distally extending portion configured to engage the distal needle interface to provide a space between the valve and the distal end of the injection system body.

21. 20. The system of claim 19, the distally extending portion is configured to engage the distal needle interface to couple the valve to the injection system body, and a distal surface of a circumferential gasket of the valve is configured to contact a distal end of the injection system body.

22. 22. The system of claim 21, The system, wherein the circumferential gasket is configured to form a fluid-tight seal with an interior surface of a distal end of the injection system body.

23. 22. The system of claim 21, The system of claim 1, wherein the circumferential gasket has an outer periphery that is smaller than an inner periphery of the injection system body.

24. 22. The system of claim 21, the distally extending portion configured to engage the distal needle interface to provide a space between the valve and the distal end of the injection system body.

25. 1. An injection system comprising: an injection system body defining a proximal opening at a proximal end thereof and a distal needle interface at a distal end thereof; a proximal stop member and a distal stop member disposed within the injection system body, the proximal stop member and the distal stop member forming a proximal drug chamber therebetween and a distal stop member and a distal drug chamber between the distal stop member and a distal end of the injection system body; a plunger member configured to be manually manipulated to insert the proximal stopper member into the injection system body; an elongate fluid transfer member configured to extend at least partially through the proximal stop member to define a flow path from the distal medicament chamber to the proximal medicament chamber, the elongate fluid transfer member defining a circumferential shoulder; an insert configured to be disposed in the proximal stop member; an insert including a distally facing funnel and a pair of fingers configured to engage a circumferential shoulder of the elongate fluid transfer member to temporarily prevent distal movement of the proximal stop member relative to the elongate fluid transfer member while a flow path from the distal drug chamber to the proximal drug chamber is open;

26. 26. The system of claim 25, The system wherein the funnel is made from a cyclic olefin copolymer.

27. 26. The system of claim 25, The system wherein the pair of fingers are constructed from a metal, such as annealed stainless steel.

28. 26. The system of claim 25, the pair of fingers and the circumferential shoulder are configured such that an increase in distally directed force applied to the plunger member after the proximal drug chamber is completely collapsed overcomes the engagement between the pair of fingers and the circumferential shoulder, allowing distal movement of the proximal stopper member relative to the elongate fluid transfer member.

29. 26. The system of claim 25, The system according to claim 1, wherein the circumferential shoulder has a larger diameter than a remainder of the elongated fluid transfer member.

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