WO2024054430A1

WO2024054430A1 - Auto-injector

Info

Publication number: WO2024054430A1
Application number: PCT/US2023/031975
Authority: WO
Inventors: Jeffrey Richard Held; Steven Michael Madland; John Bartholomew
Original assignee: University Hospitals Cleveland Medical Center
Current assignee: University Hospitals Cleveland Medical Center
Priority date: 2022-09-06
Filing date: 2023-09-05
Publication date: 2024-03-14
Anticipated expiration: 2025-03-06

Abstract

An auto-injector is disclosed. The auto-injector includes a housing, a syringe support, a syringe assembly, an activation sleeve, a lower compression spring, a drive spring sleeve, and an upper compression spring. In an initial state, the activation sleeve and the drive spring sleeve engage each other via hooks and hold the syringe assembly within the housing. When the activation sleeve is pushed into the housing, the hooks separate and the upper compression spring pushes the drive spring sleeve and the syringe assembly downwards to expose the needle and inject the medication. The lower compression spring is compressed, and then extends to push the activation sleeve back out to cover the needle. The hooks on the drive spring sleeve then lock the activation sleeve in place.

Description

AUTO-INJECTOR

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 63/404,018, filed on September 6, 2022, which is incorporated by reference in its entirety.

BACKGROUND

[0002] The present disclosure relates to auto-injectors used to deliver medication through the skin of a patient through a needle. Several medications are commonly administered via auto-injection devices by parents or caregivers. For example, insulin is administered for the treatment of diabetes. Another common medication administered by parents or caregivers includes epinephrine for treating severe allergic reactions.

[0003] There is a need for further automatic injection devices.

BRIEF DESCRIPTION

[0004] The present disclosure relates to auto-injection devices. The auto-injectors include multiple components that work together to deliver medication. An activation sleeve extends from the housing in an initial state. When the auto-injector is pressed against the user and pushes the activation sleeve into the housing, a drive spring sleeve is released from a locked position, and a syringe assembly extends from the housing into the patient and releases the medication. The activation sleeve is then pushed out from the housing again to act as a needle shield.

[0005] Disclosed in various embodiments are auto-injectors. The auto-injectors comprise a housing, a syringe support, a syringe assembly, an activation sleeve, a lower compression spring, a drive spring sleeve, and an upper compression spring. The housing has an orifice at a lower end thereof. The syringe support is fixed in place in the lower end of the housing, and includes an upper tube, a support ledge and a lower tube. The syringe assembly has an upper end surrounded by a syringe carrier, a plunger rod extending through the syringe carrier, and a lower end located within the syringe support. The activation sleeve is located within the lower tube of the syringe support. The activation sleeve includes a lower end extendable through the orifice of the housing and an upper end having a plurality of hooks thereon. The lower compression spring is biased against the activation sleeve and the syringe support. The drive spring sleeve has an upper end which engages the plunger rod and a lower end with a plurality of hooks. The upper compression spring is biased against an upper end of the housing and the drive spring sleeve. In an initial state, each hook of the activation sleeve engages a hook of the drive spring sleeve and the hooks of the drive spring sleeve rest on the support ledge of the syringe support, such that the drive spring sleeve is pushed against an upper end of the housing.

[0006] The syringe support may further comprise a plurality of circumferential slots in the support ledge, vertical passages in the lower tubular sidewall aligned with the circumferential slots that form lower stop surfaces, and vertical ribs on either side of each vertical passage.

[0007] The syringe assembly may further comprise a barrel having a flange which is located within the syringe carrier, a piston within the barrel, and a needle. The plunger rod may also be located within the barrel, engaging the piston. The syringe assembly may further comprise a rigid needle shield surrounding the needle.

[0008] In some embodiments, the activation sleeve further comprises an annular channel between an inner tube and an outer tube in which the lower compression spring is located. The activation sleeve may further comprise a shaft through the lower end of the sleeve.

[0009] In other embodiments, each hook of the activation sleeve is also vertically aligned with an alignment member and a lower ramp. The span between the alignment member and the lower ramp may be sized to receive a hook of the drive spring sleeve.

[0010] In further embodiments, the drive spring sleeve further comprises an annular support surface which engages the upper compression spring. The drive spring sleeve may further comprise a plurality of holes for engaging tabs at an upper end of the housing.

[0011] In particular embodiments, the housing comprises a baseplate and an exterior body. The baseplate includes the orifice and engages the syringe support. The exterior body may be formed from a cylindrical sidewall and a top end plate. The top end plate may further comprise a plurality of tabs that pass through the drive spring sleeve and engage the syringe carrier in the initial state.

[0012] The drive spring sleeve and the housing may each further comprise dowel holes that are aligned with each other.

[0013] The auto-injector may further comprise a safety cap that engages the lower end of the activation sleeve. The safety cap may include a rigid needle shield puller for removing a rigid needle shield from the syringe assembly.

[0014] In particular embodiments, the syringe carrier comprises an upper piece and a lower piece which interlock with each other. The upper piece has an opening, the lower piece has an opening, and the lower piece opening has a diameter that is greater than a diameter of the upper piece opening.

[0015] In the initial state, the lower end of the activation sleeve may extend out the orifice at the lower end of the housing. In an intermediate state, the lower end of the activation sleeve may be pressed into the housing. In a final state, the drive spring sleeve is pushed against the lower end of the housing and the lower end of the activation sleeve extends out the orifice at the lower end of the housing.

[0016] The exterior body may include windows through which the drive spring sleeve is visible in the final state.

[0017] Also disclosed herein are methods for delivering a dose of a medication through an auto-injector. An auto-injector is received. An activation sleeve of the autoinjector is placed against a user's limb. The auto-injector is pressed downwards, pushing the activation sleeve into the auto-injector, and a needle to extend and penetrate into the user and deliver the dose of medication. The auto-injector is then lifted from the limb, causing the activation sleeve to extend and cover the needle.

[0018] These and other non-limiting aspects of the present disclosure are more particularly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following is a brief description of the drawings, which are presented for the purposes of illustrating the exemplary embodiments disclosed herein and not for the purposes of limiting the same. [0020] FIG. 1 is a cross-sectional view of one embodiment of an auto-injector of the present disclosure, in a first or initial state.

[0021] FIGS. 2A-2F are different views of a syringe support used in the auto-injector. FIG. 2A is a perspective view. FIG. 2B is a front exterior view. FIG. 2C is a front cross- sectional view across line A-A of FIG. 2A. FIG. 2D is a side exterior view. FIG. 2E is a top plan view. FIG. 2F is a bottom plan view.

[0022] FIGS. 3A-3E are different views of an activation sleeve used in the autoinjector. FIG. 3A is a perspective view. FIG. 3B is a front exterior view. FIG. 3C is a front cross-sectional view across line B-B of FIG. 3A. FIG. 3D is a top plan view. FIG. 3E is an exterior view of an alternative embodiment of an auto-injector that includes a shaped endplate.

[0023] FIGS. 4A-4F are different views of a drive spring sleeve 400 used in the autoinjector. FIG. 4A is a perspective view. FIG. 4B is a front exterior view. FIG. 4C is a front cross-sectional view across line C-C of FIG. 4A. FIG. 4D is a side exterior view. FIG. 4E is a top plan view. FIG. 4F is a bottom plan view.

[0024] FIG. 5A and FIG. 5B are different views of a syringe assembly used in the auto-injector. FIG. 5A is a cross-sectional view of the entire assembly. FIG. 5B is an exterior view with some parts of the assembly removed so that other details are more visible.

[0025] FIG. 6A and FIG. 6B are different views of a plunger rod used in the syringe assembly. FIG. 6A is a perspective view. FIG. 6B is a front view.

[0026] FIGS. 7A-7E are different views of a syringe carrier used in the syringe assembly. FIG. 7A is a perspective view of the syringe carrier, which is assembled from an upper piece and a lower piece. FIG. 7B is a perspective view of the upper piece. FIG. 7C is a top plan view of the upper piece. FIG. 7D is a perspective view of the lower piece. FIG. 7E is a top plan view of the lower piece.

[0027] FIG. 8A and FIG. 8B are different views of a baseplate used to form a housing for the auto-injector. FIG. 8A is a perspective view of the baseplate. FIG. 8B is a bottom view of the baseplate.

[0028] FIGS. 9A-9F are different views of an exterior body used together with the baseplate to form the housing. FIG. 9A is a perspective view. FIG. 9B is a front exterior view. FIG. 90 is a front cross-sectional view across line D-D of FIG. 9A. FIG. 9D is a side exterior view. FIG. 9E is a front cross-sectional view across line E-E of FIG. 9A. FIG. 9F is a bottom plan view.

[0029] FIG. 10 is a perspective view of a clip used in the auto-injector.

[0030] FIGS. 11A-11 E are views of two different embodiments of a safety cap 900 used with the auto-injector, in accordance with the present disclosure. FIG. 11A is a perspective view of a rigid needle shield (RNS) puller that is part of the safety cap. FIG. 11 B is a perspective view of a first embodiment of the safety cap. FIG. 11C is a cross- sectional view of the first embodiment. FIG. 11D is a perspective view of a second embodiment of the safety cap. FIG. 11E is a cross-sectional view of the second embodiment.

[0031] FIGS. 12A-12G illustrate various views for assembly of the auto-injector.

[0032] FIGS. 13A-13G are modified cross-sectional views showing various states during operation of the auto-injector.

[0033] FIGS. 14A-14C are illustrations of different variations of the auto-injector. FIG. 14A is a cross-sectional view of a first variation. FIG. 14B is an exterior view of a second variation. FIG. 14C is an exterior view of a third variation.

DETAILED DESCRIPTION

[0034] A more complete understanding of the devices and methods disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the existing art and/or the present development, and are, therefore, not intended to indicate relative size and dimensions of the assemblies or components thereof.

[0035] Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function. In the following specification and the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings. [0036] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0037] As used in the specification and in the claims, the term "comprising" may include the embodiments "consisting of" and "consisting essentially of." The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named components/steps and permit the presence of other components/steps. However, such description should be construed as also describing devices or methods as "consisting of and "consisting essentially of" the enumerated components/steps, which allows the presence of only the named components/steps, and excludes other components/steps.

[0038] Numerical values in the specification and claims of this application should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value. All ranges disclosed herein are inclusive of the recited endpoint.

[0039] The term “about” can be used to include any numerical value that can vary without changing the basic function of that value. When used with a range, “about” also discloses the range defined by the absolute values of the two endpoints, e.g. “about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” may refer to plus or minus 10% of the indicated number.

[0040] It should be noted that many of the terms used herein are relative terms. For example, the terms “upper” and “lower” are relative to each other in location, i.e. an upper component is located at a higher elevation than a lower component in a given orientation. The terms “top” and “bottom” or “base” are also relative to each other, as are the terms “upward” and “downward”. The terms “inlet” and “outlet” are relative to a direction of flow, and should not be construed as requiring a particular orientation or location for a device. The terms “upstream” and “downstream” are relative to the direction in which a fluid flows through various components, i.e. the fluid flows through an upstream component prior to flowing through the downstream component. The terms “horizontal” and “vertical” are used to indicate direction relative to an absolute reference, i.e. ground level. However, these terms should not be construed to require structures to be absolutely parallel or absolutely perpendicular to each other. These relative terms are intended to encompass different orientations of the device in use or operation, and should be interpreted accordingly.

[0041] The present disclosure relates to autoinjection devices, also known as syringes, injectors, or auto-injectors. The auto-injector is operated using a pressing motion along an axis generally normal to the patient. Generally, the auto-injector includes a syringe support, an activation sleeve, a syringe assembly, a drive spring sleeve, and two springs which are all contained within a housing.

[0042] Components

[0043] FIG. 1 is a cross-sectional illustration of an auto-injector 100 of the present disclosure in a first or initial state, in accordance with some embodiments.

[0044] The auto-injector 100 includes a housing 110, which is illustrated as being made from a baseplate 700 and an exterior body 800. The housing has an upper end 112 and a lower end 114. An orifice (not visible) is present at the lower end of the housing, in the baseplate 700. An activation sleeve 300 is present at the lower end of the housing. The upper end 302 of the activation sleeve is located within, and surrounded by, a syringe support 200. The lower end 304 of the activation sleeve is covered by a safety cap 900. A lower compression spring 130 is biased against the activation sleeve 300 and the syringe support 200. A syringe assembly 500 is shown. The lower end 504 of the syringe assembly is located within the syringe support 200. A drive spring sleeve 400 is located above the syringe assembly. The syringe assembly includes a plunger rod 550 which is attached to the upper end 402 of the drive spring sleeve. An upper compression spring 120 is biased against the drive spring sleeve 400 and the upper end 112 of the housing. The upper compression spring will act as the drive spring for injecting the medication into the patient or user.

[0045] The upper spring 120 and the lower spring 130 are both compression springs. Without an applied load, they are long, and they get shorter as load is applied. Put another way, each spring is biased to be long. At a shorter length, the spring has stored energy. [0046] FIGS. 2A-2F are different views of the syringe support 200 in isolation. FIG. 2A is a perspective view. FIG. 2B is a front exterior view. FIG. 2C is a front cross- sectional view across line A-A of FIG. 2A. FIG. 2D is a side exterior view. FIG. 2E is a top plan view. FIG. 2F is a bottom plan view.

[0047] Referring to all of these figures together, the syringe support 200 can be described as being formed from the combination of an upper tube 210 and a lower tube 220, which are joined together by a horizontal surface or support ledge 230. The syringe support has an upper end 202 and a lower end 204.

[0048] The upper tube 210 includes a tubular sidewall 212. The lower tube 220 also includes a tubular sidewall 222, into which recesses have been made on each side. As seen in FIG. 2B, the upper tube has height 213, and the lower tube has height 223. As illustrated here, the lower tube height 223 is greater than the upper tube height 213.

[0049] As best seen in the cross-sectional view of FIG. 2C, the interior of these two tubes is hollow, and a shaft 206 runs vertically through the syringe support 200. As seen in both FIG. 2C and FIG. 2F, the upper tube 210 extends below the support ledge 230, such that an annular channel 270 is created around the upper tube. One end of the lower compression spring is held in this annular channel.

[0050] Referring now to FIG. 2D and FIG. 2E, two vertical passages 240 have been made in the sides of the lower tube 220. Those two vertical passages are aligned with two circumferential slots 232 made in the support ledge 230. The circumferential slot 232 has a greater arc length than the vertical passage 240, or put another way, the circumferential slot 232 subtends a larger angle than the vertical passage 240 measured from the central axis. The circumferential slots 232 are located outside of the annular channel 270. In addition, two vertical ribs 242 are present on the exterior surface of the lower tube 220 on either side of each vertical passage 240, for a total of four vertical ribs. As best seen in FIG. 2D and FIG. 2F, the lower end of the vertical passage is also shaped to create lower stop surfaces 244.

[0051] Referring now to FIG. 2E and FIG. 2F, the upper tube 210 has an inner diameter 215 and an outer diameter 217, thus creating an upper annular surface 216 at the top of the syringe support. The lower tube 220 has an outer diameter 227, and the support ledge 230 is an annular surface. The two circumferential slots 232 define two internal travel passages 260. The combination of the lower tube 220 and the vertical ribs 242 define two external travel passages 262. As will be seen later, the activation sleeve 300 travels through the internal travel passages 260, and the drive spring sleeve 400 travels through the external travel passages 262.

[0052] As seen in FIG. 2A, a plurality of joints 250 are present at the bottom of the syringe support. These joints are used to attach the syringe support to the baseplate 700 (which is described further herein). More generally, the joints on the syringe support and the baseplate will be complementary to each other (e.g. male and female). Four rotating snap-fit joints are illustrated here.

[0053] FIGS. 3A-3E are different views of the activation sleeve 300 in isolation. FIG. 3A is a perspective view. FIG. 3B is a front exterior view. FIG. 3C is a front cross- sectional view across line B-B of FIG. 3A. FIG. 3D is a top plan view. FIG. 3E is an exterior view of an alternative embodiment of an auto-injector that includes a shaped endplate.

[0054] Referring to all of these figures together, the activation sleeve 300 has an upper end 302 and a lower end 304. The activation sleeve 300 can be described as being formed from the combination of an inner tube 310 and an outer tube 320, which are joined together by an annular base 330 along the bottom of the outer tube 320. The lower end 304 of the activation sleeve is at the bottom of the inner tube 310.

[0055] The inner tube 310 includes a tubular sidewall 312. The outer tube 320 also includes a tubular sidewall 322. The inner tube has height 313, and the outer tube has height 323. As illustrated here, the inner tube height 313 is greater than the outer tube height 323. As best seen in the cross-sectional view of FIG. 3C, the interior of these two tubes is hollow, and a shaft 306 runs vertically through the inner tube 310 and the overall activation sleeve. The inner tube 310 and the outer tube 320 overlap, such that an annular channel 332 is created. The annular channel faces upwards.

[0056] Referring now to FIG. 3B and FIG. 3C, a plurality of arcuate arms 340 extend upwards from opposite sides of the outer tube 320. Here, two arms are illustrated. An upper hook 342 is present at the end of each arcuate arm. Each upper hook faces outward from the outer tube, and faces downward. The outer face 344 of each upper hook is sloped to angle outwards. [0057] An alignment member 350 and a lower ramp 360 are also vertically aligned with each upper hook 342. The alignment member is located between the upper hook 342 and the lower ramp 360. The alignment member 350 also includes an upper face 352 that is sloped to angle outwards. The lower ramp includes a sloped surface 362 and a horizontal surface 364. The horizontal surface is above the sloped surface, and the sloped surface is angled inwards towards the inner tube. The upper hook 342, alignment member 350, and lower ramp 360 have approximately the same width. The vertical distance between the alignment member 350 and the lower ramp 360 is referred to as a span 355.

[0058] Referring now to FIG. 3D, the inner tube 310 has an inner diameter 315 and an outer diameter 317. The outer tube 320 also has an inner diameter 325 and an outer diameter 327. The annular channel 332 is present between the two tubes.

[0059] It is noted that in some embodiments, a separate endplate 370 can be affixed or joined to the bottom of the inner tube 310, for changing the shape of the portion which will interact with the patient / user. The endplate can be flat or can be curved to conform to the shape of a limb. The endplate could be flexible, or made of a rigid material. An example of an auto-injector having such an endplate is shown in FIG. 3E. [0060] FIGS. 4A-4F are different views of the drive spring sleeve 400 in isolation. FIG. 4A is a perspective view. FIG. 4B is a front exterior view. FIG. 4C is a front cross- sectional view across line C-C of FIG. 4A. FIG. 4D is a side exterior view. FIG. 4E is a top plan view. FIG. 4F is a bottom plan view.

[0061] Referring to all of these figures together, the drive spring sleeve 400 has an upper end 402 and a lower end 404. The drive spring sleeve 400 can be described as being formed from an inner tube 410 and an upper end plate 420 that closes off the top end of the inner tube. The upper end 402 of the drive spring sleeve is defined by the top of the inner tube 410. The inner tube 410 is formed from a tubular sidewall 412, and has height 413.

[0062] An annular support surface 430 extends outwards from the bottom of the inner tube 410. The annular support surface has height 433. Optionally, a set of vertical ribs 432 may extend upwards from the annular support surface 430. Eight vertical ribs are illustrated here. As can be seen in FIG. 1 , the annular support surface provides a support surface for the upper compression spring.

[0063] Referring now to FIG. 4B and FIG. 4C, a plurality of arcuate legs 440 extend downwards from opposite sides of the inner tube 410. Here, two legs are illustrated. The interface between the inner tube and an arcuate leg is labeled as a root 441 of the arcuate leg. A lower hook 442 is present at the end of each arcuate leg. Each lower hook faces inward from the inner tube, and faces upward. As best seen in FIG. 4D, the outer face 444 of each lower hook is flat.

[0064] Optionally, the drive spring sleeve 400 may also include an outer tube 450, which extends downward from the annular support surface 430. The outer tube is formed from a tubular sidewall 452 and has height 453. As illustrated here, the inner tube height 413 is greater than the lower tube height 453. As best seen in the cross- sectional view of FIG. 4C, the interior of both tubes 410, 450 is hollow. The area between the outer tube 450 and the arcuate legs 440 may be considered an annular channel 456, which faces downwards.

[0065] As seen in FIG. 4D, dowel holes 406 may be present on opposite sides of the drive spring sleeve. Here, they are illustrated as extending through the outer tube 450. However, if the outer tube is not present, the dowel holes may be present in the annular support surface 430. Their use will be explained further herein.

[0066] Referring now especially to FIG. 4E, the upper end plate 420 includes a set of circular holes 422 and arcuate holes 424 which extend entirely through the upper end plate. The upper end plate also includes a plunger hole 426 in its center, which also extends entirely through the upper end plate. Optionally, a set of horizontal ribs 428 may also extend upwards from the upper end plate.

[0067] Referring now to the bottom view of FIG. 4F, the inner tube 410 has an outer diameter 415. The annular support surface 430 also has an outer diameter 435, which matches the outer diameter of the outer tube. The outer faces 444 of the lower hooks are visible. Also visible are the plunger hole 426 and the circular holes 422. The arcuate holes 424 are slightly obscured by the outer faces of the lower hooks.

[0068] FIG. 5A and FIG. 5B are different views of the syringe assembly 500 in isolation. FIG. 5A is a cross-sectional view of the entire assembly. FIG. 5B is an exterior view with some parts of the assembly removed so that other details are more visible.

[0069] The syringe assembly has an upper end 502 and a lower end 504. The syringe assembly includes a barrel 510 having a flange 512 on the upper end of the barrel and a hub/adapter 514 and a needle 516 at the lower end of the barrel. A rigid needle shield (RNS) 518 surrounds the needle, . A piston I stopper I head 520 is located within the barrel 510, and is connected to the plunger rod 550. Fluid 530 is illustrated within the barrel, located between the piston 520 and the needle 516.

[0070] At the upper end of the syringe assembly, a syringe carrier 600 surrounds the flange 512. The flange 512 and an O-ring or washer 532 are located within the syringe carrier, which is formed from an upper piece 610 and a lower piece 620.

[0071] The barrel 510 has a diameter 511 , the flange 512 has a diameter 513, and the syringe carrier 600 has a diameter 605. The barrel diameter 511 is less than the flange diameter 513. The flange diameter 513 is less than the syringe carrier diameter 605. As will be seen later, the upper surface 602 and the lower surface 604 of the syringe carrier 600 each act as a stop surface.

[0072] FIG. 6A and FIG. 6B are different views of the plunger rod 550 in isolation. FIG. 6A is a perspective view. FIG. 6B is a front view.

[0073] Referring to both figures together, the plunger rod includes a pole 552 which has an upper end 554 and a lower end 556. The upper end of the pole includes a drive sleeve engagement member 560. The lower end of the pole includes a piston engagement member 562, which attaches to the piston I stopper I head 520 within the barrel (see FIG. 5A). The length 555 of the plunger rod is indicated, which does not include the two engagement members.

[0074] As illustrated here, the plunger rod 550 also includes a horizontal surface which is provided by a horizontal plate 570 at the lower end of the pole. A plurality of vertical ribs 572 may extend upwards from the horizontal plate upwards against the pole. Here, three vertical ribs are illustrated. However, the horizontal plate 570 and the vertical ribs 572 are optional, and any other suitable structure may be used. The diameter 557 of the plunger rod is measured at the lower end of the plunger rod, and is sufficient to close off the barrel 510. [0075] FIGS. 7A-7E are different views of the syringe carrier 600 in isolation. FIG. 7A is a perspective view of the syringe carrier, which is assembled from an upper piece and a lower piece. FIG. 7B is a perspective view of the upper piece. FIG. 7C is a plan view of the upper piece. FIG. 7D is a perspective view of the lower piece. FIG. 7E is a plan view of the lower piece.

[0076] Referring to FIG. 7A, the syringe carrier 600 is made up of an upper piece 610 and a lower piece 620. The upper piece 610 includes an upper plate 612 having an upper surface 602. An opening 614 is present in the upper plate 612.

[0077] As seen in FIGS. 7B and FIG. 7C, a plurality of joints 616 are located around the circumference of the upper plate, and extend below the upper plate 612. The upper plate opening 614 has a diameter 615. In addition, the syringe carrier itself has a diameter 605.

[0078] As seen in FIG. 7D and FIG. 7E, the lower piece 620 includes a lower plate 622. An opening 624 is present in the lower plate 622. As indicated on FIG. 7E, the lower plate opening 624 has a diameter 625. A plurality of joints 626 are located around the circumference of the lower plate, and extend above the lower plate 622.

[0079] The lower plate opening diameter 625 is greater than the upper plate opening diameter 615. Referring back to FIG. 5A, it can be seen that the barrel 510 of the syringe passes through the lower plate opening 624, and the pole 552 of the plunger rod 550 passes through the upper plate opening 614. The flange 512 is trapped within the syringe carrier.

[0080] The joints 616, 626 engage each other to form the syringe carrier. For example, the joints 626 in the lower piece 620 rotate clockwise when viewed from above, and the joints 616 in the upper piece 610 rotate counter-clockwise when viewed from above. Again, generally the joints of the upper piece and the lower piece will be complementary to each other. Here, the joints are illustrated as circumferential snap-fit joints.

[0081] FIG. 8A and FIG. 8B are different views of the baseplate 700 in isolation. FIG. 8A is a perspective view of the baseplate FIG. 8B is a bottom view of the baseplate. [0082] Referring first to FIG. 8A, the baseplate 700 includes a cylindrical sidewall 702 and a bottom wall 704 that is normal to the sidewall and closes off one end of the sidewall. A plurality of vertical ribs 706 may extend upwards from the bottom wall along the cylindrical sidewall. Here, three ribs are illustrated, offset 90 degrees from each other and are used for orientation. A plurality of cantilever joints 708 are arranged vertically in the cylindrical sidewall, and are used to interlock the baseplate with the exterior body. Here, four cantilever joints are illustrated.

[0083] The bottom wall 704 includes a central orifice 712, through which the needle will be deployed. A plurality of internal rotational slots 710 are also present along the interior of the sidewall 702. These slots engage the snap-fit joints 250 of the syringe support 200 (see FIG. 2A), to fix the syringe support in place at the lower end of the housing. Four slots are illustrated. It is noted that the bottom wall of the baseplate could be flat or could be curved to conform to the shape of a limb.

[0084] Referring now to FIG. 8B, the central orifice 712 is visible in the center of the baseplate. The central orifice has a diameter 713, which is sized to permit the lower end of the activation sleeve to pass through (see FIG. 3A). The four rotational slots 710 are also visible. Four circumferential slots 714 are also visible, which are located below the cantilever joints 708.

[0085] FIGS. 9A-9F are different views of the exterior body 800 in isolation. FIG. 9A is a perspective view. FIG. 9B is a front exterior view. FIG. 9C is a front cross-sectional view across line D-D of FIG. 9A. FIG. 9D is a side exterior view. FIG. 9E is a front cross-sectional view across line E-E of FIG. 9A. FIG. 9F is a bottom plan view. Together, the baseplate and the exterior body form a housing of the auto-injector.

[0086] Referring to all figures, the exterior body is formed from a cylindrical sidewall 810 and a top end plate 820, with the interior of the exterior body being visible only from the bottom. The exterior body has an upper end 802 and a lower end 804. A plurality of lower recesses 812 are present along the lower end, which extend through the exterior body. These recesses engage with the cantilever joints 708 of the baseplate (see FIG. 8A) to form the housing. Optionally, a plurality of windows 814 may be present on the exterior body, extending through the sidewall 810. The windows may be of any size or shape, and be oriented horizontally or vertically as desired. A plurality of dowel holes 816 are also present on opposite sides of the exterior body. These dowel holes 816 will align with the dowel holes 406 of the drive spring sleeve (see FIG. 4D).

[0087] The exterior body has a height 803 and a diameter 805. In some embodiments, the height is about 100 millimeters (mm). In some embodiments, the diameter is about 40 mm.

[0088] Referring to the views of FIG. 9C, FIG. 9E, and FIG. 9F, a plurality of tubular tabs 822 and a plurality of arcuate tabs 824 extend downwards from the top end plate 820. As best seen in FIG. 9F, the tubular tabs are located on opposite sides from each other, and the arcuate tabs are located on opposite sides from each other. These tabs 822, 824 will enter the holes 422, 424 present on the upper end plate 420 of the drive spring sleeve 400 (see FIG. 4E). An optional plurality of posts 826 are also present around the exterior of the top end plate 820. These posts may be used for orienting the upper compression spring 120, but are optional.

[0089] In addition, a plurality of vertical recesses 828 are present on the interior surface of the exterior body. They are offset at 90 degrees from each other, and engage with the vertical ribs 706 of the baseplate for orientation of the parts.

[0090] Referring to FIG. 9F, the exterior body has a diameter 805. The arcuate tabs 824 are located along the circumference of an imaginary circle having a tab diameter 825. The tab diameter 825 is less than the syringe carrier diameter 605 (see FIG. 7C), preventing the syringe carrier from rising to the top of the drive spring sleeve.

[0091] Continuing, FIG. 10 is a perspective view of a clip 140 which is used to secure the plunger rod 550 in place relative to the drive spring sleeve 400, as will be described later.

[0092] Next, FIGS. 11A-11E are different views of various embodiments of a safety cap 900, in accordance with the present disclosure. The safety cap is used initially to cover the lower end of the syringe and protect the patient or user from accidental discharge or needle stick. FIG. 11A is a perspective view of a rigid needle shield (RNS) puller that is part of the safety cap. FIG. 11 B is a perspective view of a first embodiment of the safety cap, and FIG. 11C is a cross-sectional view of the first embodiment. FIG. 11D is a perspective view of a second embodiment of the safety cap, and FIG. 11E is a cross-sectional view of the second embodiment. [0093] Looking first at FIG. 11 A, the RNS puller 950 is used to remove the RNS 518 from the needle (see FIG. 5A). The RNS puller is made from a cylindrical sidewall 952 that has barbs 954 therein. Both ends of the RNS puller are open. As illustrated here, barbs 954 are present on both ends, although only one end will engage the RNS. The RNS puller has a diameter 955.

[0094] Referring now to FIG. 11 B and FIG. 11C, the first embodiment of the safety cap 900 is formed from an exterior cylindrical sidewall 910 and a lower end plate 920. The exterior sidewall may be textured for easier grip. An interior post 922 is located in the center of the lower end plate 920, and is used to engage the RNS puller. The interior post can be solid or hollow, and is illustrated as being hollow. The interior post has a diameter 923, which is substantially equal to or slightly greater than the RNS puller diameter 955. The safety cap itself has an inner diameter 905. In this embodiment, the safety cap inner diameter 905 is about equal to the outer diameter 317 of the inner tube 310 of the activation sleeve 300 (see FIG. 3C). An annular channel 924 is present between the exterior sidewall 910 and the interior post 922.

[0095] Referring now to FIG. 11D and FIG. 11E, the second embodiment of the safety cap 900 includes the same components. As illustrated, the shape of the exterior cylindrical sidewall 910 is slightly different. Also, in this embodiment, the safety cap inner diameter 907 is about equal to the diameter 805 of the exterior body 800 (see FIG. 9F), or in other word is greater than the RNS puller diameter, in addition, the safety cap 900 includes a handle 930, which provides an alternate means for handling of the safety cap. A wider cap may be desirable, for example if the activation sleeve 300 includes an endplate 370.

[0096] The various components can be made of any suitable material, such as plastic, a polymeric material, a metal, or the like. For example, the springs 120, 130 and the RNS puller 950 may be made of metal, and/or the barrel 510 can be made of glass, while the other components can be made of plastic or a polymeric material. The various components can be made using suitable processes such as injection molding, 3-D printing, and the like. [0097] Assembly

[0098] The overall auto-injector can be assembled in several straight-forward steps. FIGS. 12A-12G provide various views of the assembly steps.

[0099] First, the syringe assembly 500 of FIG. 5A is made. The barrel 510, hub 514, needle 516, and rigid needle shield 518 are usually provided together as an integrated component. The barrel is filled with the desired medication or fluid 530, and the piston 520 is inserted. An o-ring 532 is slid up from the bottom of the barrel to sit underneath the flange 512. Next, referring also to FIGS. 7A-7E, the syringe barrel 510 is inserted through the opening 624 of the lower piece 620 of the syringe carrier so the o-ring 532 abuts the lower piece. The plunger rod 550 is then inserted into the syringe barrel. The upper piece 610 of the syringe carrier is then slid over the plunger rod down to the lower piece, and the two pieces are rotated together. The plunger rod 550 extends through the opening 614 in the upper piece 610 of the syringe carrier. The plunger rod may a;sp be described as extending through the syringe carrier.

[0100] Next, referring to FIG. 12A, a lockout subassembly is made. The activation sleeve 300 is placed into the orifice in the baseplate 700. The lower compression spring 130 is inserted into the annular channel of the activation sleeve, and the syringe support 200 is then placed onto the lower compression spring. The syringe support 200 is then pushed downwards to compress the lower compression spring 130. The syringe support is then rotated so that the snap-fit joints 250 of the syringe support 200 engage the internal rotational slots (not visible) of the baseplate. The engagement of the joints can be checked by looking up through the bottom of the baseplate (see FIG. 8B).

[0101] Next, referring to FIG. 12B and to FIG. 6A, the syringe assembly 500 is attached to the drive spring sleeve 400. The drive sleeve engagement member 560 of the plunger rod is inserted through the plunger hole of the drive spring sleeve, and the clip 140 is used to secure the plunger rod in place.

[0102] Next, referring to the cross-sectional view of FIG. 12C, the upper compression spring 120 is inserted into the exterior body 800. The drive spring sleeve 400 (with the attached syringe assembly) is then placed into the center of the upper compression spring 120, and pushed down into the exterior body. When the dowel holes 406 of the drive spring sleeve line up with the dowel holes 816 of the exterior body, dowel pins (not shown) are inserted into the dowel holes to lock these components into place. The resulting structure is referred to herein as a drive subassembly. As seen in FIG. 12C, at least the arcuate tabs 824 pass through the upper end plate of the drive spring sleeve 400 and engage the syringe carrier 600.

[0103] The lockout subassembly is then attached to the drive subassembly. The lockout subassembly is inserted into the exterior body. The arcuate legs 440 of the drive spring sleeve should be pushed outwards by the arcuate arms 340 of the activation sleeve until the hooks snap and lock together. If needed, the internal volume of the exterior body can be accessed through the windows 814. The cantilever joints 708 of the baseplate 700 engage the lower recesses 812 of the exterior body 800.

[0104] Next, the safety cap 900 is added. The RNS puller 950 is mounted onto the interior post 922 of the safety cap. The safety cap and RNS puller are then inserted into the activation sleeve 300. The safety cap should be pushed in until flush against the baseplate 700. The auto-injector is thus assembled. The dowel pins can then be removed from the dowel holes, and the auto-injector is armed. An exterior view of the final structure 100 is seen in FIG. 12D. The auto-injector is ready for use, and can be considered an “initial” state for the auto-injector.

[0105] Some additional views are provided to show the interaction between various components of the auto-injector.

[0106] FIG. 12E shows some aspects of the interaction between the syringe support 200, the activation sleeve 300, and the drive spring sleeve 400. As can be seen here, and with reference back to FIGS. 2A-2F and FIG. 3A, the arcuate arms 340 of the activation sleeve will travel vertically through the circumferential slots and the internal travel passages 260 of the syringe support 200. The upper hook 342, alignment member 350, and lower ramp 360 will travel vertically through a vertical passage 240 in the lower tube 220 of the syringe support. The arcuate legs 440 of the drive spring sleeve will travel vertically between the vertical ribs 242 of the syringe support 200, through the external travel passages 262.

[0107] FIG. 12F is a cross-sectional view showing the interaction between certain parts of the syringe support 200 and the syringe assembly 500. As can be seen here, the lower end 504 of the syringe assembly is located within or surrounded by the upper tube 220 of the syringe support. The barrel 510 engages the upper tube 210 of the syringe support.

[0108] Finally, FIG. 12G shows how some components interact near the lower end of the auto-injector. Here, the safety cap 900, RNS puller 950, baseplate 700, activation sleeve 300, and the lower compression spring 130 are illustrated. As seen here, the RNS puller 950 is mounted to the interior post 922, and extends upwards past the annular channel 332 of the activation sleeve almost to the end of the lower compression spring 130, for engaging the RNS of the syringe assembly. The lower end of the activation sleeve 300 fits into the annular channel 924 of the safety cap.

[0109] Operation

[0110] The auto-injector is used to delivery medication to a patient or user. FIGS. 13A-13G are modified cross-sectional views that illustrate the auto-injector in operation. [0111] FIG. 13A shows the auto-injector 100 in an initial state. As can be seen here, the safety cap 900 is in place, with the RNS puller engaging the RNS (not visible). The activation sleeve 300 is located within the lower tube of the syringe support 200. The upper hooks 342 of the activation sleeve 300 and the lower hooks 442 of the drive spring sleeve 400 are interlocked. The lower hooks 442 are secured between the upper hooks 342 and the support ledge 230 of the syringe support, and rest on the support ledge. The drive springe sleeve 400 is pushed against the upper end 112 of the housing 110. The upper compression spring 120 is compressed between the upper end 112 of the housing and the drive spring sleeve 400. The lower end 504 of the syringe assembly 500 is located within the upper tube 210 of the syringe support 200. The syringe carrier 600 is pushed up against the arcuate tabs 824 extending from the top of the housing.

[0112] In FIG. 13B, the safety cap has been removed. The needle 516 is now exposed. As better seen here, the lower end 304 of the activation sleeve extends through the orifice 712.

[0113] In FIG. 13C, as the auto-injector is pushed downwards against the skin of the patient or user, the lower end 304 of the activation sleeve is pushed into the housing 110. The lower compression spring 130 becomes compressed against the syringe support 200. As the arcuate arms 340 of the activation sleeve travel upwards, the upper hooks 342 and the alignment members 350 together push the arcuate legs 440 of the drive spring sleeve outwards and off the support ledge 230.

[0114] In FIG. 13D, because the arcuate legs 440 are no longer holding the drive spring sleeve 400 up, the upper compression spring 120 extends, pushing the drive spring sleeve downwards. The syringe assembly 500 also travels downwards, with the needle 516 traveling out through the orifice 712 and piercing the skin of the patient or user. The downward travel of the barrel stops when the syringe carrier 600 contacts the upper annular surface of the upper tube 210. However, the plunger rod 550 continues traveling downwards with the drive spring sleeve. This causes the piston 520 to eject the fluid I medication out through the needle 516. The lower tube 220 of the syringe support continues to push the arcuate legs 440 outwards.

[0115] FIG. 13E illustrates an intermediate state of the auto-injector 100. Here, the drive spring sleeve 400 has now been pushed down as far as possible by the upper compression spring 120. The upper end plate 420 rests against the syringe carrier 600. The syringe carrier 600 is resting upon the upper annular surface of the upper tube 210. The arcuate legs 440 are no longer pushed outwards, and snap back into place. As a result, the lower hooks 442 engage the lower stop surface 244 of the syringe support. The outer tube 450 of the drive spring sleeve rests upon the cylindrical sidewall 702 of the baseplate. The lower compression spring 130 is compressed between the syringe support 200 and the activation sleeve 300. The needle 516 still extends out of the orifice 712.

[0116] In FIG. 13F, the lower compression spring 130 now begins to extend, pushing the activation sleeve 300 downwards. As the activation sleeve travels downward, the lower ramps 360 push the lower hooks 440 of the drive spring sleeve outwards, away from the lower stop surface 244. However, the upper compression spring 120 continues to hold the drive spring sleeve down in place.

[0117] FIG. 13G shows the auto-injector in a final state. After the lower ramps 360 on the activation sleeve pass the lower hooks 442, the lower hooks snap back into the span 355 between each lower ramp 360 and alignment member 350 of the activation sleeve (see FIG. 3C). This locks the activation sleeve 300 in place, and prevents the activation sleeve from being depressed again. The lower end 304 covers the needle 516. The needle is not retracted into the housing. It is noted that the drive spring sleeve 400 is still held down in place near the lower end of the housing. A window aligned with the drive spring sleeve in this location could be used to indicate whether the auto-injector has been used or not.

[0118] Discussion

[0119] The auto-injectors of the present disclosure do not contain any electronic components that may require battery power. Variations on the structure of the autoinjector are expected, and several such variations are expressly contemplated. For example, the structure may change depending on the desired fluid volume to be delivered, the viscosity of the fluid, and the injection depth. For example, the length of the plunger rod, the barrel diameter, the needle length, or the heights of the tubes of the syringe support could be changed.

[0120] Some variations on the auto-injector are illustrated in FIGS. 14A-14C. In the cross-sectional view of FIG. 14A, the bottom wall 704 of the baseplate 700 is curved, which can be done to permit the baseplate to conform to the shape of the user’s limb. In the view of FIG. 14B, the housing 110 includes a window 814 which is oriented vertically. In addition, the safety cap 900 includes a handle 930 which extends off to one side. In the view of FIG. 14C, the housing 100 includes a window 814 which is circular. Here, the safety cap 900 includes a handle 930 which extends downwards. In addition, in the embodiment illustrated in FIG. 3E, the activation sleeve includes a shaped endplate 370.

[0121] The present disclosure will further be illustrated in the following non-limiting examples, it being understood that these examples are intended to be illustrative only and that the disclosure is not intended to be limited to the materials, conditions, process parameters and the like recited herein.

EXAMPLES

[0122] Three prototype auto-injector devices were made and evaluated. They were tested using five tests indicated in ISO 11608-1 , which specifies requirements and test methods for needle-based injection systems intended to be used with needles and with replaceable or non-replaceable containers. Those tests were the Rigid Needle Shield (RNS) removal force, the device activation force, the needle insertion depth, the fluid delivery time, and the fluid delivery volume. The average results are shown below in Table A:

Table A.

[0123] The present disclosure has been described with reference to exemplary embodiments. Modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

CLAIMS:

1 . An auto-injector, comprising: a housing having an orifice at a lower end thereof; a syringe support fixed in place in the lower end of the housing and including an upper tube, a support ledge and a lower tube; a syringe assembly having an upper end surrounded by a syringe carrier, a plunger rod extending through the syringe carrier, and a lower end located within the syringe support; an activation sleeve located within the lower tube of the syringe support, the activation sleeve including a lower end extendable through the orifice of the housing and an upper end having a plurality of hooks thereon; a lower compression spring biased against the activation sleeve and the syringe support; a drive spring sleeve having an upper end which engages the plunger rod and a lower end having a plurality of hooks; and an upper compression spring biased against an upper end of the housing and the drive spring sleeve; wherein in an initial state, each hook of the activation sleeve engages a hook of the drive spring sleeve and the hooks of the drive spring sleeve rest on the support ledge of the syringe support, such that the drive spring sleeve is pushed against an upper end of the housing.

2. The auto-injector of claim 1 , wherein the syringe support further comprises a plurality of circumferential slots in the support ledge, vertical passages in the lower tubular sidewall aligned with the circumferential slots that form lower stop surfaces, and vertical ribs on either side of each vertical passage.

3. The auto-injector of claim 1 , wherein the syringe assembly further comprises a barrel having a flange which is located within the syringe carrier, a piston within the barrel, and a needle.

4. The auto-injector of claim 3, wherein the plunger rod is also located within the barrel and engages the piston.

5. The auto-injector of claim 3, wherein the syringe assembly further comprises a rigid needle shield surrounding the needle.

6. The auto-injector of claim 1 , wherein the activation sleeve further comprises an annular channel between an inner tube and an outer tube in which the lower compression spring is located.

7. The auto-injector of claim 1 , wherein the activation sleeve further comprises a shaft through the lower end of the sleeve.

8. The auto-injector of claim 1 , wherein each hook of the activation sleeve is also vertically aligned with an alignment member and a lower ramp.

9. The auto-injector of claim 8, wherein a span between the alignment member and the lower ramp is sized to receive a hook of the drive spring sleeve.

10. The auto-injector of claim 1 , wherein the drive spring sleeve further comprises an annular support surface which engages the upper compression spring, and a plurality of holes for engaging tabs at an upper end of the housing.

11. The auto-injector of claim 1 , wherein the housing comprises a baseplate and an exterior body, the baseplate including the orifice and engaging the syringe support.

12. The auto-injector of claim 11 , wherein the exterior body is formed from a cylindrical sidewall and a top end plate, and the top end plate further comprises a plurality of tabs that pass through the drive spring sleeve and engage the syringe carrier in the initial state.

13. The auto-injector of claim 1 , wherein the drive spring sleeve and the housing each comprise dowel holes that are aligned with each other.

14. The auto-injector of claim 1 , further comprising a safety cap that engages the lower end of the activation sleeve.

15. The auto-injector of claim 14, wherein the safety cap includes a rigid needle shield puller for removing a rigid needle shield from the syringe assembly.

16. The auto-injector of claim 1 , wherein the syringe carrier comprises an upper piece and a lower piece which interlock with each other, the upper piece has an opening, the lower piece has an opening, and the lower piece opening has a diameter that is greater than a diameter of the upper piece opening.

17. The auto-injector of claim 1 , wherein in the initial state, the lower end of the activation sleeve extends out the orifice at the lower end of the housing.

18. The auto-injector of claim 1 , wherein in an intermediate state, the lower end of the activation sleeve is pressed into the housing.

19. The auto-injector of claim 1 , wherein in a final state, the drive spring sleeve is pushed against the lower end of the housing and the lower end of the activation sleeve extends out the orifice at the lower end of the housing.

20. The auto-injector of claim 19, wherein the exterior body includes windows through which the drive spring sleeve is visible in the final state.

21. A method of delivering a dose of a medication through an auto-injector, comprising: receiving an auto-injector; placing an activation sleeve of the auto-injector against a user’s limb; pressing the auto-injector downwards, pushing the activation sleeve into the auto-injector, and a needle to extend and penetrate into the user and deliver the dose of medication; lifting the auto-injector from the limb, causing the activation sleeve to extend and cover the needle.