Self-injection device

Abstract

An autoinjector comprising a compressed gas source including a rigid container having a non-rigid sealing structure, and a syringe with a seal and a plunger stopper defining a working space between the plunger stopper and the seal. The autoinjector further comprises a puncture needle that is fluidly coupled or connectable to the working space. The puncture needle is further axially aligned and selectively pierces the non-rigid sealing structure of the compressed gas source upon relative axial movement between the non-rigid sealing structure of the compressed gas source and the compressed gas source to fluidly couple the puncture needle to the compressed gas source.

Description

[Technical field]

[0001] This patent disclosure claims priority to U.S. Provisional Patent Application No. 63 / 254,291, filed October 11, 2021, which is incorporated herein by reference for all purposes.

[0002] The present disclosure relates generally to injectable drug delivery devices, related methods and manufacture. In particular, the present disclosure relates to drug delivery devices that administer injection therapy using an energy source contained within the device. [Background technology]

[0003] Self-administration devices are designed to allow patients to administer injectable therapies in a non-clinical environment (e.g., at home) or typically in other non-clinical settings. Traditional syringes require the user to provide the necessary force to administer the injectable medication. This force is characterized using the Hagen-Poiseuille equation. To assist the user, self-administration devices contain a stored energy source, such as a compressed spring, to provide the necessary force to inject the medication. Drug delivery devices in this category include autoinjectors and wearable internal injectors (patch pumps).

[0004] Autoinjectors were first introduced in the 1970s to protect soldiers during chemical warfare. Since then, many medications are increasingly being injected by patients themselves using autoinjectors. The most commonly used autoinjectors include a compression spring that provides the force required to administer the injectable medication. Autoinjectors that use an electromechanical power source to drive the injection of the medication are less common.

[0005] As new pharmaceutical treatments are developed, demands on the performance of autoinjectors increase. Furthermore, as treatment moves from hospitals and clinics to the home environment, more people are using autoinjectors to treat health conditions, creating an even greater demand to ensure that autoinjectors can be used error-free.

[0006] One of the trends in pharmaceutical development is the increasing viscosity of drug formulations, for example, due to more potent (highly concentrated) biologics, larger injection volumes, and long-acting formulations. The higher the viscosity of the drug formulation, the greater the injection force or the longer the injection time. Most of the conventional spring-based autoinjectors would need to employ stronger springs, which would result in a larger size of the autoinjector. Large autoinjectors are inherently difficult to handle, which is considered as a key requirement for self-administration. In addition, large autoinjectors may be unstable during the injection procedure. It has been reported that the glass syringe filled with the drug may break in spring-based autoinjectors. It is believed that the stronger the spring, the greater the amplitude of the impact on the glass syringe when the spring is released. Therefore, incorporating a strong spring into a viscous formulation may not be the optimal method.

[0007] Electromechanical power-based autoinjectors are well positioned to provide additional power for viscous formulations while providing a more compact device. However, these autoinjectors can be expensive. As a result, these autoinjectors are more practical as reusable autoinjectors due to cost and disposal issues.

[0008] Recently, compressed gas has been used as a power source in autoinjectors with small compressed gas cylinders. Compressed gas autoinjectors present a number of design challenges. Compressed gas cylinders are typically manufactured from metal with a welded seal. Breaking the welded seal releases gas that advances a plunger rod that slides within the hermetically sealed cylinder, which pushes against a plunger stopper to inject the medication. Most single-syringe autoinjectors include this plunger rod.

[0009] A large actuation force is required to release the compressed gas because a welded seal must be broken. Therefore, a lever-type actuator is usually required for practical use of compressed gas autoinjectors. Extensive piping is required to deliver the compressed gas to the plunger stopper.

[0010] It is also important to ensure that the puncture pin used to break the weld seal is hermetically sealed and that the compressed gas is transported to the syringe without leakage. The main complaint with compressed gas powered autoinjectors is the leakage of compressed gas during storage and during the injection process. The compressed gas is usually an inert gas such as nitrogen, carbon dioxide, or argon. The release of compressed gas can cause recoil, which can cause the needle to accidentally become dislodged from the injection site.

[0011] With a plunger rod advanced by compressed gas, a large force may be applied to the plunger stopper, and if this applied force is not coaxial, the plunger rod may be thrown off by the plunger stopper, resulting in erroneous drug delivery and compromising the integrity of the container closure.

[0012] Maintaining flow rate can be achieved by ensuring that the volume of drug is much smaller than the total volume that the gas from the compressed gas source can occupy after perforation. Another approach is to incorporate a dual-phase gas in the compressed gas chamber.

[0013] Notwithstanding the above, there are significant advantages to using compressed gas as a power source. The power source is more compact. Also, for the same pressure, the force available to drive the plunger stopper in the syringe using a compressed gas source increases, as the injection volume increases and the cross-sectional area of ​​the syringe increases. Autoinjectors with compressed gas power sources are disposable, making them more practical, which may be an advantage with certain medications.

[0014] For first-time users, autoinjectors are inherently difficult to use without error. One study showed that when operated without instruction, 69% of study participants prematurely removed the autoinjector from the injection site before the injection was completed. This can be particularly problematic for drugs that are injected infrequently, where patients may not have access to a replacement drug. This lost dose occurs when the needle safety mechanism activates shortly after the autoinjector is removed from the injection site. The drug is expelled from the autoinjector despite the needle safety shield being locked. This locking occurs regardless of whether the full dose has been administered. Addressing this skill gap can reduce a significant burden of treatment adherence. Summary of the Invention [Means for solving the problem]

[0015] The disclosed invention details a compressed gas source that is incorporated into multiple embodiments of an autoinjector. The embodiments disclosed herein are intended to improve upon other compressed gas autoinjector technologies and shortcomings of other autoinjectors. The autoinjector embodiments include features that improve ease of use and address some of the gaps in current autoinjector technology. The novel features disclosed herein may be applied to autoinjectors that do not have a compressed gas power source.

[0016] The disclosed invention also outlines a method of manufacture.

[0017] The disclosed invention includes a compressed gas source consisting of a container that is pierceable but has a closure element that hermetically seals around a piercing element (such as a sharp hollow metal tube / needle). When the tube is removed, the pierceable closure element reseals, maintaining high pressure within the compressed gas source.

[0018] This unique feature enables several improvements over the prior art.

[0019] In addition to autoinjectors, it is envisioned that this compressed gas source may also be used in, but is not limited to, wearable internal injectors, drug delivery devices, and the like.

[0020] The disclosed invention is a compact, high performance autoinjector powered by a compressed gas source.

[0021] According to one aspect of the present disclosure, an autoinjector for use in injecting an injectable medicament with compressed gas is provided. The autoinjector includes a compressed gas source and a syringe attached together by a housing. The compressed gas source includes a rigid container defining an interior space and an opening to the interior space, and a non-rigid sealing structure arranged and configured to seal the opening to the interior space so as to maintain the compressed gas in a compressed state. The syringe includes a barrel, a syringe needle fluidly coupled to an interior of the barrel, a plunger stopper arranged to move within the barrel, and a seal arranged to seal the barrel opposite the syringe needle. The plunger stopper is radially disposed within the barrel and separates the interior of the barrel into a medicament space configured to contain an injectable medicament between the plunger stopper and the syringe needle and an operating space between the plunger stopper and the seal. The autoinjector further includes a puncture needle. The puncture needle is axially aligned to selectively pierce the non-rigid sealing structure of the compressed gas source upon relative axial movement between the puncture needle and the compressed gas source to fluidly couple the puncture needle and the compressed gas source. At least one of the compressed gas source and the puncture needle is movably mounted such that the puncture needle selectively pierces the non-rigid sealing structure to selectively fluidly couple the compressed gas source to the working space.

[0022] According to another aspect of the present disclosure, a compact sealed compressed gas source is provided. The compressed gas source includes a rigid container, a non-rigid sealing structure, a crimp sleeve, and a conical rigid structure. The rigid container includes an enlarged neck portion defining an interior space and defining an opening to the interior space. The non-rigid sealing structure is arranged and configured to seal the opening to the interior space. The non-rigid sealing structure is at least partially disposed within the opening. The crimp sleeve includes a generally cylindrical portion disposed around and crimped below the enlarged neck portion of the rigid container and a generally radially extending portion defining an aperture aligned with the opening to the interior space. The crimp sleeve is arranged to prevent outward movement of the non-rigid sealing structure from the enlarged neck. The conical rigid structure is arranged to exert a sealing force against the non-rigid sealing structure. The conical rigid structure may be formed by the crimp sleeve itself or may be formed by another structure such as a conical washer. The compressed gas is disposed within the interior space of the rigid container.

[0023] According to a further aspect of the present disclosure, there is provided a method of making such a compact sealed gas source by inserting a non-rigid sealing structure into an opening to an interior space of the rigid container, disposing a crimp sleeve around an enlarged neck portion of the rigid container such that a conical rigid structure is positioned to exert an inward sealing force on the non-rigid sealing structure, crimping the crimp sleeve around the enlarged neck portion, and filling the rigid container with compressed gas.

[0024] According to yet another aspect of the present disclosure, there is provided a method of fluidly connecting a working volume of a syringe with a compressed gas source to provide compressed gas to axially move a plunger stopper within a barrel of the syringe to inject an injectable medicament. [Brief description of the drawings]

[0025] [Figure 1]FIGURE 1-1 is a schematic diagram of a stepped side elevation of the components of an autoinjector, partially sectioned, in accordance with the teachings of the present disclosure, during administration of an injectable medication. FIGURE 1-2 is a schematic diagram of a stepped side elevation of the components of an autoinjector, partially sectioned, in accordance with the teachings of the present disclosure, during administration of an injectable medication. FIGURE 1-3 is a schematic diagram of a stepped side elevation of the components of an autoinjector, partially sectioned, in accordance with the teachings of the present disclosure, during administration of an injectable medication. [Diagram 2] FIG 2-1 is an exploded perspective view of the compressed gas source of FIG 1. FIG 2-2 is a cross-sectional view of the assembled compressed gas source of FIG 1 and FIG 2-1. FIG 2-3 is an enlarged fragmentary partial cross-sectional view of the compressed gas source of FIG 1, FIG 2-1, and FIG 2-2. [Diagram 3] 1 is a cross-sectional view of components of an alternative embodiment of an autoinjector in accordance with the teachings of the present disclosure, and an enlarged fragmentary cross-sectional view of the autoinjector; [Figure 4] 1A and 1B are exploded and perspective views of an alternative embodiment of a compressed gas source according to aspects of the present disclosure, and a perspective view of an assembled compressed gas source; [Diagram 5] 5-1 and 5-2 are side views of an autoinjector according to an embodiment of the present disclosure, with a cap placed on the housing and the cap removed from the housing, respectively. [Figure 6] FIG. 6 is an exploded perspective view of the autoinjector according to FIG. 5. [Figure 7] FIG. 7 is a side view of the interior of the front and rear housings of the autoinjector of FIGS. 5 and 6. [Figure 8] 7A-7C are a series of partial side views of the needle safety mechanism of the autoinjector of FIGS. 5-6. [Figure 9] Fig. 9-1 is a perspective view of the carrier of the autoinjector of Fig. 5 to Fig. 6. Fig. 9-2 is a perspective view of the carrier of Fig. 9-1 with the compressed gas source and pinion gear of Fig. 5 to Fig. 6. [Figure 10] FIG. 7 is a perspective view of a push rod of the autoinjector of FIGS. 5-6. [Figure 11]11-2 to 11-5 show use of the syringe of FIGS. 5 to 6 with the housing removed. [Figure 12] 1 is a side view of an alternative embodiment of an autoinjector in accordance with the teachings of the present disclosure. FIG. [Figure 13] FIG. 13 is an exploded perspective view of the autoinjector according to FIG. 12. [Figure 14] 14 is a series of side views of the autoinjector of FIGS. 12-13 during an injection procedure. [Figure 15] FIG. 15 is a side view of the interior of the rear housing and a side view of the interior and exterior of the front housing of the autoinjector of FIGS. 12 to 14. [Figure 16] 15A-15C are perspective and side views of a dose indicator disposed through a window in the front housing of the embodiment of FIGS. 12-14, and a partial perspective view of the dose indicator. [Figure 17] FIG. 15 is a perspective view of the relay of the embodiment of FIGS. 12 to 14. [Figure 18] 15A-15C are side views of the slider of FIGS. 12-14 and a series of partial side views of a needle safety mechanism of the autoinjector. [Figure 19] 15A-15C are a series of partial views (with the housing removed) of the use of the syringe of FIGS. 12-14 to deliver a dose. [Figure 20] Fig. 20-1 is a partial side view of the autoinjector of Figs. 12-14 before injection, and Fig. 20-2 is a partial side view of the autoinjector of Figs. 12-14 after injection. [Figure 21] 15A-15C are partial side views of the autoinjector of FIGS. 12-14, respectively, before and after injection. [Figure 22] 11A-11C are a series of side schematic views of a further embodiment of an autoinjector. [Diagram 23] FIG. 7 is a cross-sectional view of the autoinjector of FIGS. 5 to 6. [Figure 24] FIG. 15 is a cross-sectional view of the autoinjector of FIGS. 12 to 14. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] According to the present disclosure, an autoinjector 18 (see Figs. 5 and 6) is provided, which includes a syringe 1 and a compressed gas source 6. Fig. 1 shows a general schematic diagram of administering an injectable medicament 9 contained in the syringe 1 using a compressed gas source 6 according to the present disclosure. The syringe 1 includes a needle 1a connected to a barrel 1b, and a plunger stopper 2 is axially movable through the barrel 1b to administer the injectable medicament 9 through the needle 1a. A needle adapter 3 is connected to the syringe 1 on the opposite side to the needle 1a. With reference to Fig. 1-1, the plunger stopper 2 contacts the injectable medicament 9 on one side and faces the needle adapter 3 on the other side. The syringe 1, the plunger stopper 2, and the needle adapter 3 are coaxially arranged. The needle adapter 3 is hollow and connects an axially extending lumen of the connected puncture needle 5 to the space between the needle adapter 3 and the plunger stopper 2. A circular seal 4 is disposed within the barrel 1b of the syringe 1 between the needle adapter 3 and the plunger stopper 2. The seal 4 isolates the lumen of the needle adapter 3 and the interior of the barrel of the syringe 1 from the outside environment.

[0027] The compressed gas source 6 is in the form of a canister or vial that is generally rigid, but includes a non-rigid portion 7 that can be punctured by the puncture needle 5. An exemplary compressed gas source 6 is described in more detail below with reference to FIG. 2. The compressed gas source 6 is aligned with the puncture needle 5 secured in the needle adapter 3 such that the non-rigid portion 7 of the compressed gas source 6 is directly opposite the tip of the puncture needle 5 extending from the needle adapter 3. In at least one embodiment, the puncture needle 5 is ideally sized at 25G or less and is longer than necessary to fully pierce the non-rigid portion 7 of the compressed gas source 6. The non-rigid portion 7 is made of a non-porous (or low-porosity) elastomeric (or equivalent) material. In at least one embodiment, this component may be coated or infused with an additive to further reduce its porosity.

[0028] 1-1 to 1-3 are schematic diagrams showing the connection of the syringe 1 and the needle adapter 3 to the compressed gas source 6 and the actuation of the injection. FIG. 1-1 shows the state before the needle adapter 3 is connected to the compressed gas source 6 for the actuation of the injection. FIG. 1-2 shows the start of the injection in which the container 6 of the compressed gas source is moved axially toward the puncture needle 5, the tip of the puncture needle 5 passes through and penetrates the non-rigid portion 7 of the compressed gas source 6, and the lumen of the puncture needle 5 and the adapter 3 are connected to the high pressure gas enclosed in the compressed gas source 6. Referring to FIG. 1-3, the compressed gas in the container 6 flows through the needle adapter 3 into the space between the needle adapter 3 and the plunger stopper 2. As long as the pressure of the compressed gas in the space 8 between the needle adapter 3 and the plunger stopper 2 provides sufficient force to overcome the sliding force of the plunger stopper 2 and the force required to overcome the resistance to the flow of the fluid in the syringe, the plunger stopper 2 advances to the end of administration position as shown in FIG. 1-3.

[0029] According to one aspect of the present disclosure, the rigid portion of the compressed gas source 6 is constructed of a material and has a thickness capable of holding compressed gas at high pressure. The material may be, for example, stainless steel, but may also be constructed of plastic, so long as the rigid portion of the compressed gas source 6 is rigid enough to withstand high internal pressures. The puncture needle 5 is formed of any suitable material, such as metal or hard plastic. In at least one embodiment, the outer surface of the puncture needle 5 may be lubricated.

[0030] Although the disclosed compressed gas source 6 has been described in detail and illustrated in the drawings with respect to a syringe 1, those skilled in the art will appreciate that the disclosed configuration may be applied to drug delivery devices other than autoinjectors.

[0031] Those skilled in the art will further appreciate that actuation of the syringe 1 to administer the injectable medicament 9 occurs when the compressed gas source 6 and the needle adapter 3 are moved relatively toward one another. That is, administration may be initiated when the compressed gas source 6 and the needle adapter 3 are physically moved toward one another, when the compressed gas source 6 is moved toward the tip of the puncture needle 5 of the fixed needle adapter 3, or when the needle adapter 3 is moved toward the fixed compressed gas source 6.

[0032] FIG. 2 provides details of one embodiment of the structure of an exemplary compressed gas source 6. The exploded view 2-1 of the compressed gas source 6 shows a rigid container 10, a non-rigid part 11, a pad 12, a conical washer 13, and a crimp sleeve 14. The rigid container 10 is configured to withstand pressure exerted by compressed gas contained therein. For example, the rigid container 10 could be constructed using stainless steel, aluminum, or plastic, or the like. The rigid container 10 includes an enlarged portion 17 that defines an opening to the interior of the rigid container 10. The crimp sleeve 14 includes a generally generally cylindrical outer portion 14c that defines an aperture 14a and is sized to surround the enlarged portion 17. The crimp sleeve 14 may further include a generally radially extending portion 14b that defines the aperture 14a and extends inwardly from the generally cylindrical outer portion 14c, or the generally radially extending portion 14b may be formed by crimping the generally cylindrical outer portion 14c around the enlarged portion 17 of the rigid container. The non-rigid part 11 is placed within an opening in the interior of the rigid container 10 and seals the contents. The non-rigid part 11 is soft enough for a needle to pass through and pliable enough to seal against the surface of the rigid container 10. The pad 12 is placed on top of the non-rigid part 11 and helps prevent the non-rigid part from expanding when high pressure compressed gas is trapped inside. The pad 12 is thick enough to be easily pierced by a needle, but thick enough not to break when resisting pressure from the trapped compressed gas. The diameter of the pad 12 is larger than both the inner diameter of the conical washer 13 and the diameter of the aperture of the crimp sleeve 14. In at least one embodiment, the non-rigid part 11 is pre-placed in the portion of the rigid container 10 that has the smallest cross-sectional area.

[0033] FIG. 2-2 shows a cross-sectional view of the assembled compressed gas source 6 with all the aforementioned components. The assembly is performed by axial compression and simultaneous deformation of a portion of the crimp sleeve 14 towards the axis of the rigid container 10, thereby fixing all the components. It can be seen that the central portion of the conical washer 13, located between the crimp sleeve 14 and the non-rigid part 11 of the compressed gas source 6, is arranged to apply an axially inward force to the non-rigid part 7 of the compressed gas source, here the pad 12 and the non-rigid part 11. In this way, the axially inward force exerted by the conical washer 13 and the crimp sleeve 14 exerts an outward force on the non-rigid part 11 or the neck part of the plug against the inner surface of the rigid container 10, here the inner diameter of the enlarged portion 17 of the region 16. Those skilled in the art will understand that the crimp sleeve 14 and the conical washer 13 may be formed as a unitary structure, i.e., the crimp sleeve 14 may include an inner surface that faces conically inward towards the non-rigid part 11. In an arrangement that does not include the conical washer 13 or another conical structure of the crimp sleeve 14 exerting an inward force on the center of the non-rigid part 11 and is not oriented as shown in FIG. 2-1, the non-rigid part 11 may seal against the rigid container 10 only at region 15 as shown in FIG. 2-3. This may be similar to how a pharmaceutical vial would normally establish a seal to close the container. However, this amount of sealing may be insufficient for the high pressure of the compressed gas. When compressed by the crimp sleeve 14 during assembly, the inverted conical washer 13 (or such integral structure) provides an angled outward compressive force on the non-rigid part 11, allowing additional sealing at region 16. This maintains high pressure within the compressed gas source 6 and reduces the risk of gas leakage.

[0034] FIG. 3 shows an alternative embodiment of the needle adapter and syringe, as well as the compressed gas source 6. In FIG. 3, a cross-sectional view of the embodiment is shown in a partially enlarged view, showing the forces acting on the compressed gas source 6, as well as the puncture of the non-rigid portion 7 by the puncture needle 5 of the needle adapter 3. The arrows indicate the pressure exerted on the non-rigid part 11 by both the compressed gas and the crimp sleeve 14 and washer 13. The presence of the high pressure gas and the opposing pressure exerted by the crimp sleeve 14 and washer 13 compresses the non-rigid part 11 axially, which results in the non-rigid part 11 being pushed out radially. However, the non-rigid part 11 is also radially restrained by the crimp sleeve 14. This effectively reduces or eliminates the porosity of the elastomeric non-rigid part 11. Furthermore, when the puncture needle 5 is inserted into the elastomeric non-rigid part 11, the dynamics described above provide a radial compressive force that seals the inlet around the puncture needle 5, sealing the compressed gas source 6 after the puncture needle 5 is removed. In this way, the non-rigid part 11 effectively acts like a valve. Those skilled in the art will appreciate that in accordance with the teachings of this disclosure and the appended claims, embodiments of an autoinjector can be provided that incorporate a valve for controlling the flow of compressed gas that powers the injection.

[0035] Furthermore, as an alternative to the embodiment of the compressed gas source 6 as described above, various options for modifying the design of the crimp sleeve 14 may allow the need for the washer 13 and / or pad 10 to be avoided.

[0036] In at least one embodiment, the sealing surfaces are highly polished to ensure a good seal. The shape factor of the compressed gas source 6 can be modified to accommodate higher pressures, for example, the rigid container 6a can be provided with a hemispherical bottom, etc. (see FIG. 4). Those skilled in the art will appreciate that modifications to facilitate filling can be provided as well, including the incorporation of valves. In at least one embodiment, the compressed gas source 6 can be filled with pressurized gas using a needle that is inserted at an angle into the non-rigid part 11 for filling and then retraced its path of entry and removed. However, other methods of filling compressed or liquid-phase gas without the use of a needle that pierces the non-rigid part 11 are also contemplated by the present disclosure.

[0037] FIG. 5 illustrates one embodiment of an autoinjector 18 incorporating the compressed gas source 6 described above. FIG. 5-1 illustrates the autoinjector embodiment 18 having a housing 22 and a cap 19. The housing 22 may include a window through which the injectable medication 9 and the syringe plunger stopper 2 are visible. As shown in FIG. 5-2, removal of the cap 19 exposes a needle safety shield 20 that blocks the view of the needle contained in the autoinjector 18. Removal of the cap 19 also removes the needle cover 21.

[0038] According to a feature of at least one embodiment, actuation of an injection is accomplished by fully retracting the needle safety shield 20. Once the injectable medication 9 has been fully delivered and the user has removed the autoinjector 18 from the injection site, the safety shield 20 locks, preventing accidental needle stick injuries from the biohazardous needle.

[0039] FIG. 6 is an exploded view of the autoinjector 18 showing the various components contained therein, and a cross-sectional view of the assembled autoinjector is shown in FIG. 23. Longitudinally split housings 22-1 and 22-2 enclose the components of the autoinjector 18. Although the illustrated embodiment shows a longitudinally split housing, for manufacturing reasons it is also possible to design the housing to be split transversely to the axis of the autoinjector 18. The compressed gas source 6 is housed in a carrier 25 and is biased away from the needle adapter 3 by a biasing element, here a spring 24. The spring 24 is axially supported by a disk 23, which also serves as an axial stop for the syringe 1. The disk 23 includes a centrally located lumen to allow the needle adapter 3 to pass therethrough.

[0040] The syringe 1 is coupled to the housing 22 using a clip 29, which has tabs that screw into the housings 22-1 and a mechanism 32 on the housings 22-1 when closed. The slider 30 surrounds the outer surface of the syringe 1 and is configured to rotate about the axis of the syringe 1. The slider 30 includes a mechanism that serves to retain the needle safety shield 20, which is biased away from the slider 30 by a safety spring 28. As will be explained in more detail with respect to FIG. 10, the push rods 26-1 and 26-2 transfer motion from the safety shield 20 to the carrier 25 via a rack 48 that engages with a pinion gear 27. The cap 19 serves to close the autoinjector 18 and also includes a mechanism that allows the needle shield of the syringe 1 to be removed when the cap is removed. Thus, when the cap 19 is removed, the autoinjector 18 is ready for injection.

[0041] FIG. 7 shows the internal features of the rear housing 22-1 and the front housing 22-2. The two housings can be attached to close the autoinjection device by pushing the cylindrical posts 31 into the slightly undersized hexagonal holes 30. The tracks 32 provide threads for the tabs 29a of the clip 29 to secure the syringe 1. When the tabs 29a ride on the tracks 32, the clip 29 rotates relative to the housing 22. The feature 33 facilitates the positioning of the pinion gear 27 of the push rod 26 within the housings and relative to the mating components. A window 34 allows easy viewing of the injectable medication 9 contained in the syringe 1 mounted within the rear housing 22-1 and the front housing 22-2. The tracks 35 and 36 are configured as axial keying features for the elements of the needle safety shield 20. Slot 37 is configured to receive push rods 26-1 and 26-2 and allows axial movement of push rods 26-1, 26-2 as a result of rotation of pinion gear 27 mounted at 33 and engagement with rack 48. Slot 38 provides axial and rotational retention for disk 23, projection 23a of disk 23 being received within slot 38. Cylindrical slot 39 on both housings provides axial retention for slider 30, cylindrical slot 39 configured to receive flange 30a of slider 30. Cavity 40 is configured to receive carrier 25.

[0042] 8, there is shown a needle safety mechanism which in this embodiment operates independently of the drug delivery mechanism. The slider 30 is a hollow cylindrical structure including a protruding cylindrical flange portion 43 which, when assembled, is received within a slot 39 in the housing 22-1, 22-2 to axially constrain the slider 30 while allowing it to rotate relative to the housing 22. The slider 30 further includes at least one track 41 within an outer wall of the slider 30. The needle safety shield 20 includes at least one pin 44 extending radially inward. The track 41 is configured to allow the at least one pin 44 of the needle safety shield 20 to move along a predetermined path to control the position of the safety shield relative to the slider 30.

[0043] The locking beam 42 prevents the needle safety shield 20 from retracting after the injection procedure is completed, thereby preventing accidental needle stick injuries. Figure 8-1 shows the safety spring 28 between the slider 30 and the needle safety shield 20. In at least one embodiment, at least a portion of the needle safety shield 20' is transparent (see Figure 8-2) to allow the operator to visualize the operation of the needle safety module.

[0044] The radially inwardly directed pin 44 of the needle safety shield 20 is arranged to be positioned and ride within the track 41 to retain the needle safety shield 20' despite the compressed safety spring 28 and to control the relative position of the needle safety shield 20 and the slider 30. When the cap 19 is initially removed from the autoinjector 18, the needle safety shield 20 and the slider 30 are in the position shown in Figs. 8-1 and 8-2. When the autoinjector 18 is pressed axially against a surface and the safety shield 20 is retracted, the pin 44 moves vertically along the track 41. When the pin 44 comes against the surface 50, the surface 50 guides the pin 44 to the position shown in Fig. 8-3, with the slider 30 rotating relative to the needle safety shield 20. This may be considered similar to the situation when a needle is inserted into an injection site. Since the needle safety shield 20' is axially fixed and rotationally constrained in the tracks 35 and 36, the slider 30 rotates slightly with the pin 44 guided by the surface 50. Once the injection is completed and the needle is removed from the injection site, the pin 44 follows another path guided by the surface 51 to a position below the lock beam 42. Since the needle safety shield 20' is axially fixed and rotationally constrained in the tracks 35 and 36, the slider 30 rotates further. That is, the axially acting separation force exerted by the spring 28 may exert a separation force between the needle safety shield 20 and the slider 30. However, as the pin 44 moves downward in the track 41, it engages and moves along the surface 51 of the track 41, causing the slider 30 to rotate further relative to the needle safety shield 20, preventing the pin from returning to the position of FIG. 8-2. Rather, as spring 28 continues to exert a separating force, slider 30 and needle safety shield 20 move to the relative positions shown in FIG. 8-5. At this point, slider 30 may be partially visible or may completely obscure window 34, providing visual confirmation that the device has been used. The height of pin 44 is ideally equal to the wall thickness of slider 30.

[0045] Although the slide and lock arrangement has been described with respect to pins 44 arranged to travel in tracks 41 on slider 30, those skilled in the art will appreciate that alternative arrangements may be provided for controlling the axial movement of needle safety shield 20 between a shield or safety position in which syringe needle 1 a is not axially exposed and an injection position in which syringe needle 1 a is axially exposed for injection. By way of example only, a track may be provided along the inner surface of housing 22, with pins extending radially outwardly from needle safety shield 20.

[0046] Turning now to retention of the compressed gas source 6 within the housing 22, the carrier 25 is shown in Figures 9-1 and 9-2 and includes a retention feature 46 positioned and configured to retain the compressed gas source 6. To facilitate axial movement of the compressed gas source, the carrier 25 further includes at least two linear racks 45 having teeth that mesh with the pinion gears 27. The pinion gears 27 rotate about pins 47 disposed in the mechanism 33 of the rear housing 22-1.

[0047] One of the axial keying features of the needle safety shield 20 is axially aligned with a protrusion 49 on the push rod 26 (shown in FIG. 10). A rack 48 on the push rod 26 meshes with teeth on the pinion gear 27 that are diametrically opposite the rack 45. This arrangement ensures that the push rod 26 and carrier 25 always move axially in opposite directions to each other. Thus, retracting the needle safety shield 20 retracts the push rod 26, which in turn causes the carrier 25 to advance the compressed gas source 6 towards the needle adapter 3 to facilitate administration of the enclosed medicament 9.

[0048] The sequence of steps from start to finish is shown in Figure 11. Figure 11-1 shows the autoinjector 18 with the medication 9 and plunger stopper 2 visible, the cap 19 removed, and the needle safety shield 20 in contact with the surface of the injection site. Figure 11-2 shows the same orientation of the autoinjector 18 without the housings 22-1 and 22-2. Here, it is shown how the axial keying feature of the needle safety shield 20 is axially aligned with the protrusion 49 of the push rod 26. The safety spring 28 is placed in a slightly compressed state between the needle safety shield 20 and the slider 30. This is the "ready to inject" position. Figure 11-2' shows the same "ready to inject" position, but with the autoinjector rotated slightly on its axis to better view the components when describing the operation of the device. In this state, the spring 24 biases the compressed gas source 6, located in the carrier 25, away from the tip of the puncture needle 5 in the needle adapter 3. When the user applies an axial force indicated by the arrow in FIG. 11-3, the needle safety shield 20 pushes the push rod 26 in the direction opposite to the arrow shown, which causes the pinion gear 27 to rotate in the clockwise direction as shown. This causes the carrier 25 and the compressed gas source 6 to advance to the tip of the puncture needle 5 of the needle adapter 3, eventually puncturing the non-rigid part 11 of the compressed gas source 6. Here, the spring 24 disposed between the compressed gas source 6 and the disk 23 is compressed. Similarly, as shown in FIG. 11-3, when the needle 1a of the syringe 1 enters the injection site, the spring 28 disposed between the needle safety shield 20 and the slider 30 is compressed. Here, the plunger stopper 2 moves from the administration start position in FIG. 11-3 to the administration end position in FIG. 11-4 while the needle 1a of the syringe 1 is at the injection site below the surface of the skin.

[0049] After the medication 9 has been fully administered, the autoinjector 18 is removed from the injection site in the direction of the arrow in FIG. 11-5. The spring 24 and safety spring 28 work in conjunction to passively lock the needle safety shield 20 (previously described and shown in FIG. 8). Also, the compressed gas source 6 is decoupled from the tip of the puncture needle 5 of the needle adapter 3. The high pressure in the chamber 8 behind the plunger stopper 2 is then released through the tip of the puncture needle 5 of the needle adapter 3.

[0050] The unique self-sealing properties of the non-rigid parts 11 of the compressed gas source 6 allow this embodiment to release high pressure from the syringe 1 chamber after drug delivery is complete. If desired, depressurization of the compressed gas source 6 after drug delivery can also be accomplished.

[0051] A second embodiment of an autoinjector device 52 incorporating a compressed gas source 6 is shown in FIG. 12. This embodiment of the autoinjector 52 differs from the previous embodiment of the autoinjector 18 in that the compressed gas source 6 is fixed. Also, in this embodiment of the autoinjector 52, a dose indicator 53 is implemented that is tethered to the plunger stopper 2. Also unique to embodiment 52 is how, by slightly modifying the slider 30 from the autoinjector 18 embodiment, the tether indicator 53 activates the needle safety only near the end of dose delivery.

[0052] FIG. 13 is an exploded view of the components of embodiment 52, and a cross-sectional view is provided in FIG. 24. Some components of embodiment 52 are common to embodiment 18. All components are enclosed within a rear housing 60-1 and a front housing 60-2. The front housing 60-2 also has a window 53a through which the dose indicator 53 is visible. A transparent cover (not shown) for the window 53a may be optionally included. The front housing 60-2 may be engraved (or printed) with various visual cues that indicate the status of dose delivery relative to the axial position of the dose indicator 53. The dose indicator 53 is connected to an adapter 54 via a tether 55, which is secured to the plunger stopper 2. The adapter 54 may be coupled to the plunger stopper 2 by any suitable arrangement. For example, the adapter 54 may be threaded onto the plunger stopper 2 or may have barbs for secure attachment to the plunger stopper 2. The adapter 54 may also consist of an O-ring for sealing against the inner surface of the syringe 2, which, at least in some embodiments, eliminates the need for physical attachment to the plunger stopper 2. The connection between the tether 55 and the adapter 54 and / or the dose indicator 53 may be made by any suitable arrangement. For example, such a connection may be provided by crimping or welding or insert molding to ensure a secure attachment. When assembled as a taut tether 55, the movement of the dose indicator 53 is synchronized with the plunger stopper 2.

[0053] The syringe 1 has a staked needle 1a and contains an injectable medication 9. The slider 56 is concentric with the syringe 1 and can rotate about the axis of the syringe 1. The slider 56 has a mechanism for engaging with the needle safety shield 28 arranged coaxially therewith, with the spring 28 arranged therebetween. The slider 56 is axially constrained by mechanisms in the housings 60-1 and 60-2, and also by a shoulder at the bottom of the syringe 1. However, as in the first embodiment, the slider 56 is rotatable about the axis of the syringe 1. The slider 56 also has a mechanism for engaging with a relay 59, which transmits the linear movement of the indicator 53 to facilitate the rotation of the slider 56. The push rod 57 is axially fixed to the needle safety shield 20. The push rod 57 transmits linear motion to actuate the retraction of the needle safety shield 20 to deliver the dose to the puncture needle 61. Before injection (or when received by the user), one tip of the puncture needle 61 points to the compressed gas container but is outside the compressed gas container. The other tip of the puncture needle 61 is embedded inside the syringe 1, past the adapter 58, on the side of the plunger stopper 2 that does not contact the drug. The adapter 58 may be one elastomeric part including an elastomer that forms a seal between the tip of the puncture needle 61 and the inner surface of the syringe 1, or it may be multiple parts. The adapter 58 is axially fixed by the disk 23. The puncture needle 61 and the push rod 57 may be axially fixed to each other or may be manufactured as one part by insert molding the puncture needle 61 to the push rod 57. A biasing element such as a spring 24 biases the push rod 57 (and the puncture needle 61) away from the compressed gas source 6.

[0054] Cap 19 may be designed to be flush with housings 60-1 and 60-2. Cap 19 also engages the needle cap of syringe 1 such that when cap 19 is removed, the needle is exposed.

[0055] FIG. 14 illustrates various steps in the operation of the autoinjector 52. Removal of the cap 19 exposes the needle safety shield 20. In at least one embodiment, the dose indicator 53 is located at the location of the "START" sign engraved on the front housing 60-2. When the autoinjector 52 is pushed towards the surface of the injection site in the direction of the arrow, the dose indicator 53 moves from a "start" position at 14-3 to an "end" position at 14-4, which occurs in synchronism with the movement of the plunger stopper 2 (not shown), which is connected to the dose indicator 53 by a tether 55. When the device embodiment 53 is pulled away from the surface of the injection site, as shown in 14-5, a portion of the slider 56 is visible, while the syringe 1 and its contents are hidden. Those skilled in the art will appreciate that the surface design of the slider 56 can be modified to allow for a visible view of the contents of the syringe 1 corresponding to 14-5.

[0056] FIG. 15 shows the front housing 60-2 and the rear housing 60-1 of the autoinjector 52. Some features inside both housings 60-2 and 60-1 are identical in function to the features on the front housing 22-2 and the rear housing 22-1 and are therefore labeled as such. The longitudinal slits 63 provide a track for the projections 64 (see FIG. 16) of the dose indicator 53 to move from start to end of dose. The features 62 allow the beams 63 (see FIG. 16) of the dose indicator 53 to push in and snap into the indents 71 (see FIG. 16) on the front housing 60-2. The number and pattern (spacing) of the indents can also be altered to create a snap pattern(s) for a more discernible audible indicator(s).

[0057] The relay 59 is shown in FIG. 17. A flat portion of the projection 64 of the dose indicator 53 impacts a surface 65 of the relay 59 near the end of the dose. A pin 66 extending axially inward from the longitudinal member 59a of the relay 59 articulates along a ramp 69 of the slider 56 (see FIG. 18). The slider 56 differs slightly from the slider 30 of the autoinjector 18 of the first embodiment. More specifically, the ramp 41 on the slider 30 of the autoinjector 18 guides the pin 44 past the point of no return 70, whereas the track 68 of the slider 56 of the autoinjector 52 does not itself guide the pin 44 past the point of no return 70. The effect of this is that the locking mechanism of the needle safety shield 20 in embodiment 52 is not believed to be activated unless the pin 44 is guided past the point of no return 70, despite the safety needle shield 20 being retracted multiple times. This requires rotating the slider 56 , which can be achieved by means of a ramp 69 and a pin 66 of the relay 59 .

[0058] 18, a series of partial side views of the needle safety mechanism of the autoinjector 52 are shown. FIGS. 18-1 and 18-1' show the location of the various components as received by the user. When the autoinjector 52 is pressed against the target surface, the user retracts the needle safety shield 20 as shown in 18-2. Once the dose delivery is complete, the axially fixed pin 66 rides on the ramp 69 of the slider 56. Since the position of the slider 56 is axially fixed by the mechanism 67 in the slot 39 of the housings 60-1 and 60-2, the slider 56 is forced to rotate when the pin 66 is driven axially by the dose indicator 53 (not shown). This rotation causes the pin 44 to pass the point of no return as shown in FIG. 18-3. At 18-4, as the spring 28 biases the needle safety shield 20 away from the slider 56, the pin 44 of the needle safety shield 20 passively (without user effort) moves down the ramp 51 by the force provided by the spring 28, and is eventually positioned under the lock beam 42.

[0059] Figure 19 shows various stages of interaction between the dose mechanism and the needle safety mechanism. Figures 19-1 and 19-1' show different angles of the components before the dose delivery starts. Figure 19-2 shows that an axial force is applied to move the autoinjector 52 towards the injection site, which results in the needle safety shield 20 being retracted, moving the plunger stopper 2 from the start of dose position in Figure 19-2 to the end of dose position in Figure 19-3, triggering the start of the injection. At this time, the protrusion 64 of the dose indicator 53 impacts the surface 65 of the relay 59. The plunger stopper 2, which drives the movement of the dose indicator 53 via the tether 55, reaches the end of dose position shown in Figure 19-4. The pin 66 of the relay 59 is now at the bottom of the ramp 69 of the slider 56. In Figure 19-5, when the spring 28 is extended as far as possible, the needle safety shield is locked out and the pin 44 moves downwards along the ramp 51 of the slider 56.

[0060] FIG. 20 shows the selection components before the start of an injection (FIG. 20-1) and at the end of a dose delivery (FIG. 20-2). To activate the autoinjector 52 and start an injection, the needle safety shield 20 (not shown) is retracted to push the push rod 57 perpendicularly against the spring 24. This causes the puncture needle 61 (not shown in FIG. 20-2 and FIG. 20-3), which is axially fixed to the push rod 57, to insert its tip into the non-rigid part 11 of the compressed gas container 6. This allows pressurized gas to enter the puncture needle 61. A path is provided for the compressed gas to travel through tether 55 and puncture needle 61 directly to syringe 1. Axially fixed seal 58 ensures that this compressed gas is directed only to advance plunger stopper 2 towards the end-of-dose position. Since plunger stopper 2 is fixed to dose indicator 53, the dose indicator moves towards the end-of-dose position in synchronism with plunger stopper 2. The inlets of both tether 55 and puncture needle 61 (piercing seal or circumferential seal) are sealed by seal 58.

[0061] FIG. 21 further illustrates the transfer of compressed gas for drug injection. FIG. 21-1 represents the stage before the start of injection. One tip of the puncture needle 61 is placed between the seal 58 and the plunger stopper 2 in the space 8. In FIG. 21-1, the space 8 is at atmospheric pressure. The other tip of the puncture needle 61 points to a compressed gas source spaced away from the non-rigid part 11 of the compressed gas container 6. When the tip of the puncture needle 61 advances past the non-rigid part 11 of the compressed gas container 6 due to the retraction of the needle safety shield 20 (not shown), the compressed gas is provided with a path to the space 8, which advances the plunger stopper 2 to complete the injection, as shown in FIG. 21-2, and the dose indicator 53 is fully advanced at the end of the administration. When the needle safety shield 20 leaves the injection site, the push rod 57 (not shown in FIG. 21-3) moves the puncture needle 61 away from the non-rigid part 11 of the compressed gas container 6. This causes compressed gas to be released from chamber 8 through the tip of the now unsealed puncture needle 61 in the side of compressed gas container 6 .

[0062] As mentioned above, the needle safety shield 20 is not locked out until the end of the dose is reached in the autoinjector 52. This means that if the user removes the embodiment 52 from the injection site before the injection is completed, the safety shield 20 is not locked, but the compressed gas in the chamber 8 is released and the injection is stopped (paused). When the user retracts the needle shield 20 and reinserts the injection needle, the pressurized gas flow is reintroduced and the injection resumes by re-establishing the connection between the compressed gas container 6 and the space 8. It is assumed that the remaining injection will be at a lower flow rate because some of the pressure was released when the injection was paused. Although it is possible to pause an injection multiple times, pausing an injection may only be a last resort. As outlined here, the unique ability to pause an injection may be beneficial for new patients who are not familiar with using an autoinjector. This unique mechanism of pausing and resuming an injection using an autoinjector eliminates the possibility of medication being wasted due to mistakes. There may be several other benefits. The ability to pause an injection is not known to be implemented in non-electronically driven autoinjectors. To the best of our understanding of the state of the art for non-electronically actuated autoinjectors, if the user removes the autoinjector from the injection site (accidentally or otherwise), the device continues to release medication into the environment, wasting medication. A wasted dose is a lost dose. However, even with this mechanism for pausing injection, a small amount of medication may still be lost due to inertia.

[0063] In FIG. 22, another embodiment is shown that allows the suspension of the injection in an autoinjector. In the case of a gas-driven autoinjector, this embodiment allows the injection to be suspended without losing pressure. The schematic shows a dose indicator 53 that can be attached to the plunger stopper 2 or a component that abuts it (only the dose indicator 53 is shown). The ratchet stop 72 has a sawtooth pattern and is biased by a spring 73. The flat part of the sawtooth pattern faces the flat part of the protrusion 64 of the dose indicator 53. In this embodiment, the power source would drive the dose indicator 53 via a connection to the plunger stopper 2 or a component that abuts the plunger stopper 2, but the advancement of the dose indicator 53 is prevented by the ratchet stop 53 as shown in 22-1. When the push rod 57' is fully retracted by the needle safety shield 20 (not shown), the ratchet stop 72 is pushed in a direction perpendicular to the direction of movement of the dose indicator 53. This releases the dose indicator 53 to allow the injection to continue as shown at 22-2. However, when the injection is interrupted by removing the autoinjector from the injection site, this causes the axially fixed push rod 57' to move in the direction shown at 22-3. As a result, the sawtooth ratchet stop 72 re-engages the dose indicator 53 as shown at 22-4. Another view from injection pause to end of injection is shown at 22-5 to 22-7.

[0064] The above approach is believed to be applicable to spring-activated autoinjectors.

[0065] Those skilled in the art will appreciate that based on the teachings of the present disclosure, other configurations for locking out the needle safety shield at the end of an injection can be realized, for example, a cam-based mechanism incorporating the concepts disclosed herein can be implemented.

[0066] The autoinjector housing can be reconfigured to split transversely to the axis of the device rather than a longitudinally split housing design, allowing for better manufacturability and assembly using pre-filled syringes.

[0067] It is envisioned that in either embodiment, the slider may be positioned coaxially with the syringe without axial overlap and still achieve the same results as set forth above.

[0068] Those skilled in the art will appreciate that the teachings of the present disclosure can be applied to embodiments of a variable dose autoinjector to control the length of tether 55 to allow the user to set the dose prior to injection.

[0069] The incorporation of electronic communication components and use of the disclosed inventions in conjunction with electronic methods of data capture, management, and transmission is contemplated as part of this disclosure.

[0070] It will be understood that the foregoing description provides examples of the disclosed autoinjectors and techniques. However, it is envisioned that other implementations of the present disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to refer to the specific examples being discussed at the time, and are not intended to imply any limitations with respect to the scope of the disclosure more generally. All distinctions and expressions of disdain regarding certain features are intended to indicate a lack of preference for those features, but are not intended to completely exclude those features from the scope of the disclosure unless otherwise specified.

[0071] Recitation of ranges of values ​​herein is intended to serve as a shorthand method of referring individually to each separate value falling within that range, unless otherwise stated herein, and each separate value is incorporated into the specification as if it were individually set forth herein. All methods described herein can be performed in any suitable order unless otherwise stated herein or otherwise clearly contradicted by context.

[0072] Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law.Furthermore, this disclosure includes any combination of the above-described elements in all possible variations unless otherwise indicated herein or clearly contradicted by context.

Claims

1. 1. An autoinjector for use in injecting an injectable medication using compressed gas, the autoinjector comprising: a compressed gas source comprising: a rigid container defining an interior space and an opening to the interior space; and a non-rigid sealing structure positioned and configured to seal the opening to the interior space to maintain the compressed gas in a compressed state; a syringe including a barrel, a syringe needle fluidly connected to an interior of the barrel, and a plunger stopper disposed for movement within the barrel, the plunger stopper being radially disposed within the barrel, the plunger stopper separating the interior of the barrel into a medicament space configured to contain the injectable medicament between the plunger stopper and the syringe needle, the syringe further including a seal disposed in contact with the barrel to form a working space within the barrel between the plunger stopper and the seal, the working space being in fluid communication with an exterior of the syringe via the seal; a housing that attaches the compressed gas source and the syringe to one another; and a hollow puncture needle axially aligned to selectively pierce the non-rigid sealing structure of the compressed gas source and fluidly connect the compressed gas source and the puncture needle upon relative axial movement between the puncture needle and the compressed gas source, wherein at least one of the compressed gas source and the puncture needle is movably attached, whereby the puncture needle selectively pierces the non-rigid sealing structure and fluidly connects the compressed gas source and the working space via the puncture needle.

2. 2. The self-injection device of claim 1, further comprising a needle safety shield slidably disposed relative to the syringe such that an axial force exerted on the needle safety shield causes the needle safety shield to slide relative to the syringe from a shielding position in which the syringe needle is not axially exposed to an injection position in which the syringe needle is axially exposed for injection.

3. 3. The autoinjector of claim 2, wherein the needle safety shield is configured to slide back to the shielding position when the axial force is removed.

4. 3. The self-injection device of claim 2, wherein movement of the needle safety shield relative to the syringe initiates relative movement between the puncture needle and the source of compressed gas.

5. An autoinjector as described in claim 4, wherein axial movement of the needle safety shield causes corresponding axial movement of the compressed gas source in an axially opposite direction to the direction of axial movement of the needle safety shield, thereby linking the needle safety shield with the compressed gas source so that the compressed gas source moves toward the puncture needle.

6. An autoinjector as described in claim 4, wherein the needle safety shield is coupled to the puncture needle such that axial movement of the needle safety shield results in corresponding axial movement of the puncture needle toward the compressed gas source, thereby moving the compressed gas source toward the puncture needle.

7. 4. The self-injection device of claim 3, comprising a biasing element arranged to slidably return to the shielded position when the axial force is removed.

8. 4. The self-injection device of claim 3, wherein the needle safety shield is axially locked in the shielding position when the axial force is removed.

9. 3. The autoinjector of claim 2, further comprising a slider, the slider rotatably disposed relative to at least the syringe, and the movement of the needle safety shield being controlled at least in part by a pin and track arrangement, one of the pin and the track being formed with the needle safety shield and the other of the pin and the track being formed with the slider, whereby movement of the pin within the track controls rotation of the slider.

10. 10. The autoinjector of claim 9, further comprising at least one biasing element, wherein the track includes a point of no return, wherein when the axial force is removed when the pin is located in the track proximal to the point of no return, the pin returns the needle safety shield to the shielding position, and when the axial force is removed when the pin is located in the track distal to the point of no return, the pin moves and locks the needle safety shield into the shielding position.

11. 11. The autoinjector of claim 10, wherein when the pin is located within the track proximal to the point of no return and the axial force is removed from the autoinjector, the puncture needle is removed from the compressed gas source such that a second axial force can be applied to the autoinjector to provide a subsequent injection from the syringe.

12. 10. The self-injection device of claim 9, further comprising a member coupled to the plunger stopper, the position of the member indicating the position of the plunger stopper within the barrel, and rotation of the slider being actuated by movement of the member coupled to the plunger stopper.

13. 13. The self-injection device of claim 12, wherein the member coupled to the plunger stopper is a dose indicator.

14. 2. The self-injection device of claim 1, wherein the puncture needle remains fluidly connected to the actuation space and is fluidly disengaged from the compressed gas source at the end of an injection, thereby releasing any remaining compressed gas in the actuation space to the atmosphere.

15. 2. The self-injection device of claim 1, further comprising a biasing element disposed between the puncture needle and the compressed gas source, the biasing element biasing the puncture needle away from the compressed gas source, the biasing element moving the puncture needle out of engagement with the compressed gas source when the axial force is terminated at the end of the injection.

16. The autoinjector of claim 1, further comprising a hollow adapter, the adapter being fluidly connected to the puncture needle and fluidly connected to the working space via an opening in the sealing portion, whereby selectively fluidly connecting the puncture needle and the compressed gas source fluidly connects the compressed gas source to the working space.

17. 2. The self-injection device of claim 1, further comprising a needle tip fluidly connected to the puncture needle on an opposite side of the compressed gas source, the needle tip configured to move axially relative to the syringe to pierce the sealing portion, whereby axial movement of the needle tip relative to the syringe fluidly connects the working space with the puncture needle.

18. 10. The self-injection device of claim 1, further comprising a status indicator that indicates the progress of delivery of the injectable medication from the syringe.

19. 20. The autoinjector of claim 18, wherein the status indicator includes a dosage indicator.

20. 20. The autoinjector of claim 19, wherein the dose indicator is slidably disposed within a dose indicator window, the dose indicator tethered to the plunger stopper such that the position of the dose indicator relative to the dose indicator window indicates the axial position of the plunger stopper relative to the syringe.

21. 20. The self-injection device of claim 19, wherein the syringe is configured to provide a series of fractions of the injectable medication.

22. The autoinjector of claim 1 , further comprising a cap removably coupled to the housing.

23. The rigid container includes an enlarged neck portion defining an opening to the interior space, the non-rigid sealing structure is at least partially disposed within the opening to the interior space, and the compressed gas source comprises: a crimp sleeve disposed around and crimped beneath the enlarged neck portion of the rigid container, the crimp sleeve including: a generally cylindrical portion crimped thereunder; and a generally radially extending portion defining an aperture aligned with the opening to the interior space, the crimp sleeve positioned to prevent outward movement of the non-rigid sealing structure from the enlarged neck portion; a conical rigid structure positioned to exert a sealing force against the non-rigid sealing structure; 10. The self-injection device of claim 1, further comprising: a compressed gas disposed within the interior space of the rigid container.

24. 24. The autoinjector of claim 23, wherein the conical-shaped rigid structure includes at least one of the generally radially extending portion of the crimp sleeve that is concave inward, and a conical washer disposed between the generally radially extending portion of the crimp sleeve and the non-rigid sealing structure.

25. 24. The autoinjector of claim 23, further comprising a pad, said pad being axially disposed along said opening to said interior space and abutting an outwardly facing surface of said non-rigid sealing structure.

26. 2. The self-injection device of claim 1, wherein the puncture needle connects the compressed gas source to the working space during injection, and connects the working space to a space outside the syringe at other times.

27. 1. A compact, sealed compressed gas source, said compressed gas source comprising: a rigid container defining an interior space, the rigid container including an enlarged neck portion defining an opening to the interior space; a non-rigid sealing structure positioned and configured to seal the opening to the interior space, the non-rigid sealing structure being at least partially disposed within the opening to the interior space; and a crimp sleeve disposed around and crimped beneath the enlarged neck portion of the rigid container, the crimp sleeve including: a generally cylindrical portion crimped thereunder; and a generally radially extending portion defining an aperture aligned with the opening to the interior space, the crimp sleeve positioned to prevent outward movement of the non-rigid sealing structure from the enlarged neck portion; a conical rigid structure positioned to exert a sealing force against the non-rigid sealing structure; a compressed gas disposed within the interior space of the rigid container; 1. A compact, sealed compressed gas source, comprising:

28. 28. The compact sealed compressed gas source of claim 27, wherein the conical rigid structure includes at least one of the generally radially extending portion of the crimp sleeve being concave inward, and a conical washer disposed between the generally radially extending portion of the crimp sleeve and the non-rigid sealing structure.

29. 28. The compact sealed compressed gas source of claim 27, further comprising a pad disposed axially along the opening to the interior space and abutting an outwardly facing surface of the non-rigid sealing structure.

30. 28. A method of manufacturing the compact, sealed compressed gas source of claim 27, comprising: inserting the non-rigid sealing structure into the opening into the interior space of the rigid container; placing the crimp sleeve around the enlarged neck portion of the rigid container with the conical rigid structure positioned to exert an axial sealing force against the non-rigid sealing structure; crimping the crimp sleeve around the enlarged neck portion by applying a radially inward deformation force; filling said rigid container with compressed gas; A method comprising:

31. 31. The method of claim 30, further comprising disposing the conical washer between the generally radially extending portion of the crimp sleeve and the non-rigid sealing structure before crimping the crimp sleeve.

32. A method for producing the compact, sealed gas source of claim 27, comprising: The method further comprising placing a pad against an outwardly facing surface of the non-rigid sealing structure.

33. A method of using an injectable medication, the method comprising fluidly connecting an actuation space of a syringe with a source of compressed gas to provide compressed gas to axially move a plunger stopper within a barrel of the syringe to use the injectable medication.

34. 34. The method of claim 33, wherein the fluid coupling occurs as a result of axial movement of the needle safety shield.

35. 1. A syringe for use in injecting an injectable medication, the syringe comprising: a syringe including a barrel, a syringe needle fluidly connected to an interior of the barrel, and a plunger stopper disposed for movement within the barrel, the plunger stopper being radially disposed within the barrel, the plunger stopper separating the interior of the barrel into a medicament space configured to contain the injectable medicament between the plunger stopper and the syringe needle; a slider axially disposed with the syringe, the slider being rotatably disposed with respect to the syringe and being substantially axially fixed with respect to the syringe; a member coupled to the plunger stopper, the position of the member being synchronized with the position of the plunger stopper within the barrel; a needle safety shield slidably disposed relative to the syringe and the slider, such that an axial force exerted on the needle safety shield causes the shield to slide relative to the syringe from a shielding position in which the syringe needle is not axially exposed to an injection position in which the syringe needle is axially exposed for injection; the movement of the needle safety shield is controlled at least in part by a pin and track arrangement, one of the pin and the track being formed with the needle safety shield and the other of the pin and the track being formed with the slider, whereby movement of the pin in the track controls the position of the needle safety shield relative to the slider, the track including a point of no return, wherein when the pin is disposed in the track proximal to the point of no return and an axial force is removed, the pin returns the needle safety shield to the shielding position such that the needle safety shield remains axially movable to the injection position, and when the pin is disposed in the track distal to the point of no return and the axial force is removed, the pin moves the needle safety shield to the shielding position with rotation of the slider and locks it; wherein rotation of the slider is actuated by movement of the member coupled to the plunger stopper, the member positioning the pin distal to the point of no return while rotating the slider to axially lock the needle safety shield in the shielding position when the plunger stopper reaches the end of delivery of the full dose.

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