Cartridge type automatic injector

Abstract

To provide an automatic injector for administration of medicine by subcutaneous, intramuscular or intracutaneous injection, for self-administration, and for medicine solution or suspension.SOLUTION: An automatic injector 101 can include three modules for facilitating assembly. The modules include a standard cartridge module having mainly a stopper and a bulkhead 104, a power source and an indicator module pressed against the cartridge stopper 104 and pressurizing the contents, an injection progress indicator, and a needle shuttle 120 consisting of two needles, one needle 121 being an injection needle, and the other needle 121 being a bulkhead needle. A needle guard 131 covers the needle 121 all the time so that the needle 121 is hidden before and after the injection, thereby preventing needle stick injury after use.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an automatic injector for the administration and self-administration of drugs by subcutaneous, intramuscular or intradermal injection and for drug solutions or suspensions. The present application describes an injection system that may be used by patients or by medical personnel for self-injection.

[0002] Auto-injectors automate the injection stroke, eliminating the need for the patient or medical practitioner to actuate the plunger rod.

[0003] The auto-injector according to the invention comprises an outer casing which holds a standard cartridge comprising a barrel in which the medicament contents are confined by a movable plunger or stopper at one end and a seal or septum at the other end and a metal crimp or cap to hold said septum in place. A biasing means pressurizes the movable plunger or stopper of the cartridge, thereby pressurizing the medicament contents. A needle shuttle held within the casing comprises two needles attached and connected to each other, the first needle being an injection needle and the second needle being a septum needle. A means or shoulder holds the cartridge in its correct position when inserted and prevents it from being pressed against the needle shuttle. A needle guard is connected to the casing and is biased outwardly, such as by a spring, such that the needle is always covered by the needle guard, thereby concealing the needle before and after injection.

[0004] The auto-injector according to the present invention may further comprise a needle guard locking mechanism that prevents the needle guard from being pushed back a second time, thereby preventing needle stick injuries after use.

[0005] The auto-injector may further comprise an indicator, which may be in the form of an indicator rod attached to and thus moving with the biasing means or the movable plunger or stopper, thereby indicating the progress of the injection progress. The indicator rod may be connected and used to operate any other indicator, such as a rotary indicator or an electronic indicator or a connectivity device.

[0006] In one embodiment, the indicator extends beyond the rear casing a distance determined by the fill volume, allowing the user to monitor the status of the injection.

[0007] In a preferred embodiment, the indicator rod has a closed end and contains a spring therein. The outer casing includes a portion that allows monitoring the progress and status of the injection progress, e.g., a cap with a transparent or viewing window. When the drug volume is fully injected, the indicator is no longer visible, indicating the end of the injection. Placing the spring within the indicator has the advantage that the spring can be longer than if the indicator were placed within the spring, and the device can be shorter. A longer spring means a larger average force, which is advantageous for viscous drugs.

[0008] The present invention further relates to a modularly designed auto-injector comprised of multiple subassemblies or modules. For ease of assembly, the modular auto-injector includes three subassemblies: a cartridge, a power supply and indicator subassembly, and a needle and needle guard subassembly.

[0009] The cartridge subassembly includes a barrel and a drug volume defined by a plunger and a crimped septum.

[0010] The power source and indicator assembly includes a biasing means or spring and an indicator rod retained within the rear casing. The present invention enables the cartridge to have a variable fill volume when assembled with the power source and indicator subassembly.

[0011] An indicator rod may be connected to move with the biasing means or spring or moveable plunger or stopper upon assembly of the device to indicate the status and progress of the injection process.

[0012] When the biasing means is a spring, the spring may further comprise a spring locking member. In this case, the power supply and indicator assembly may further comprise a second, weaker spring for pressurizing the cartridge drug contents prior to injection while the first spring is locked by the spring locking member. The second spring also avoids pressure shocks when the second spring is relaxed.

[0013] The needle and needle guard subassembly comprises a front casing which holds a needle shuttle having an injection needle and a septum needle and which holds the shuttle within the casing, a spring biased needle guard to prevent needle stick injuries, a locking mechanism to prevent the needle guard from being pushed back a second time, and means for holding the cartridge in its correct position when inserted.

[0014] The injection needle and the septum needle may have the same diameter or gauge or different diameters or gauges. The injection needle and the septum needle may have the same type of bevel tip or different types of bevel tips. For example, the septum needle may be a larger diameter or smaller gauge than the injection needle to minimize injection time. For simplicity, one needle may be used with two sharp ends or bevels. Different needle gauges and / or bevels may be used to ensure that the injection needle penetrates the injection site before the septum needle penetrates the septum to ensure complete injection. The exchange of injection needles allows for adaptation for subcutaneous, intramuscular or intradermal injection.

[0015] The modular auto-injector may be assembled by a simple two-step process, such as placing the cartridge into the needle and needle guard subassembly, and then connecting the needle and needle guard subassembly to the power and indicator subassembly so that the drug contents in the cartridge are pressurized. If the device is intended for single use, any connection means for locking the modular auto-injector subassemblies together may be used, such as a snap fit.

[0016] In a preferred embodiment, the modular auto-injector can be reassembled or used multiple times. In this case, the needle and needle guard assembly and the power supply and indicator assembly may be connected by a bayonet fit or threads or are hinged to each other to allow a reversible connection. In addition, the biasing means of the power supply and indicator assembly allows multiple uses, such as an electric motor, a liquefied gas canister or a spring with a means for recompressing itself. Finally, the needle and needle guard assembly includes a seal and a removable needle cap that keeps the needle and cartridge septum sterile at all times.

[0017] Embodiments of the auto-injector according to the present invention may be assembled under sterile conditions or may be subjected to terminal sterilization after assembly.

[0018] If the agent in the cartridge is a small molecule (non-biological), the assembled device may be terminally sterilized in the blister or pouch using gas, steam, radiation such as gamma radiation, e-beam or any other.

[0019] When sterilizing devices with sensitive drug contents such as biological agents, the blister / pouch that comprises the assembled device has at least a portion formed from a gas permeable material. The device may have a gas passageway to ensure that the needle and the exterior surface of the cartridge septum are sterilized. The device can then be placed in a gaseous environment such as ethylene oxide or nitrogen dioxide for sterilization.

[0020] To prevent the gas from affecting the sensitive drug contents, the cartridge assembly may preferably have gas impermeable components, particularly the plunger / stopper and septum / cap. The gas used should preferably not be hot, and is preferably below body temperature, preferably below 36°C.

[0021] The devices may be supplied as ready-to-use medical devices or may be supplied pre-assembled as a combination product ("kit") for self-assembly by the user.

[0022] Sterilization may occur before or after assembly, in the latter case being terminally sterilized. If sterilized before assembly, only the needle and guard subassembly or module 182 needs to be sterilized. The assembled device may be terminally sterilized in the blister or pouch. If the device is sterilized outside the blister, a needle cap and possibly a seal are required. If the device is assembled by the user, the cartridge can be supplied in a blister, or if no blister is used, the septum needs to be wiped with ethanol before device assembly.

[0023] Table 1 gives an overview of the different options regarding sterilization, with options 3 to 6 allowing for reassembly.

[0024] [Table 1]

[0025] The auto-injector according to the invention may be used with drug suspensions or solutions and APIs or biologics. If the suspension is unstable due to a tendency to settle, the cartridge needs to be shaken before use to remix.

[0026] A modular design has the advantage that each subassembly may be manufactured separately under individually adapted conditions. Furthermore, the modular design allows flexibility in manufacturing and allows different autoinjectors to share modules. The modular design also allows for part interchangeability, which creates the added advantage that modules or subassemblies can be exchanged to change the characteristics of the autoinjector. For example, by exchanging the needle and hub and needle guard assembly, the device can be changed from a subcutaneous autoinjector to an intramuscular or intradermal autoinjector. This also allows the power module to be a reusable device. A modularly designed autoinjector also allows cartridges to be replaced after use or at the end of their useful life.

[0027] The present invention allows for the use of industry standard syringe cartridges and the production of auto-injectors with dry needle storage and a variety of other advantages.

[0028] Specific embodiments of the invention will now be described with reference to the drawings. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 shows an automatic injector. [Diagram 2] FIG. 1 shows an auto-injector with an indicator rod attached to the stopper. [Figure 3a] FIG. 1 illustrates an auto-injector during an injection. [Figure 3b] FIG. 1 illustrates an auto-injector during an injection. [Figure 4] FIG. 2 shows the auto-injector after a completed injection. [Diagram 5]FIG. 1 illustrates a modular auto-injector. [Figure 6] FIG. 1 is a three-dimensional view of a modular auto-injector. [Figure 7] FIG. 13 shows a subassembly having a locking member. [Figure 8] FIG. 13 shows a subassembly with an additional spring. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 1 shows an assembled and ready-to-use auto-injector exposed to a gaseous environment for sterilization. [Figure 12] FIG. 1 shows the auto-injector assembled and ready for use. [Figure 13] FIG. 1 shows the auto-injector assembled and ready for use.

[0030] FIG. 1 shows an auto-injector 101 according to the invention. A standard cartridge 102 has a barrel 103 in which a drug solution or suspension 107 is confined by a movable plunger or stopper 104 at one end and a rubber seal or septum and metal crimp 105 at the other end. The cartridge 102 is held in a casing 110. A biasing means 112 presses against the stopper 104, pressurizing the contents 107. A needle shuttle 120 is held in the casing 110. The shuttle 120 has two needles 121 and 122 attached and connected to each other. Needle 121 is an injection needle and needle 122 is a septum needle. Means 127 hold the cartridge 103 in its correct position when inserted and prevent the cartridge 103 from being pressed against the shuttle. A needle guard 131 and a spring 132 are held in the casing 110. The needle guard 131 has the purpose of preventing needle stick injuries after an injection.

[0031] FIG. 2 shows an auto-injector 101 with an indicator rod 111 attached to the stopper 104 .

[0032] 3a and 3b show the auto-injector 101 during an injection. The auto-injector 101 is pressed against the injection site 201. The needle 121 is in the injection site 201 and delivers the drug solution or suspension 107a as a bolus dose. The needle guard 131 is pressed against the injection site 201 and is forced backwards against the casing 110 against the spring 132, forcing the shuttle 120 back. The needle 122 has pierced the septum 105 and the pressurized contents 107 flow through the needles 121 and 122 into the injection site 201, delivering the bolus dose 107a. The indicator 111 has moved forward, indicating the injection progress. To ensure a complete injection, the injection needle penetrates the injection site (FIG. 3a) before the septum needle penetrates the septum (FIG. 3b).

[0033] In FIG. 4, the auto-injector 101 has completed an injection and the needle guard 131 has been pushed back by the spring 132 and locked in place by the locking mechanism 135.

[0034] FIG. 5 shows a modular auto-injector according to the present invention which is comprised of three subassemblies: a cartridge subassembly 181, a needle and needle guard subassembly 182, and a power supply and indicator subassembly 183.

[0035] Cartridge subassembly 181 includes a cartridge 102 with a barrel 103 and a drug volume 107 retained by a plunger 104 and a septum 105 .

[0036] The power supply and indicator subassembly 183 includes a biasing means or spring 112 and an indicator rod 111 held within a casing 110a.

[0037] The needle and needle guard subassembly 182 has a casing 110b which holds the needle shuttle 120 with the needles 121 and 122. A needle guard 131 to prevent needle stick injuries is biased outwardly by a spring 132. The module 182 may be supplied sterile. The module 182 also has a guard locking mechanism, i.e. shoulder 127, which holds the cartridge 102 in its correct position when inserted (not shown).

[0038] The module 182 may include a needle for subcutaneous, intramuscular or intradermal injection.

[0039] 6 shows a three-dimensional view of the modular auto-injector. After cartridge 181 is placed into subassembly 182, subassemblies 183 and 182 are locked together in the direction of arrows 187 and 188, pressurizing the drug contents within cartridge 181.

[0040] The assembled auto-injector 184 is shown with an optional indicator cap, indicator knob 111a attached to indicator rod 111 (not shown), and an optional front cap 141, although these are optional features.

[0041] In Figure 7, subassembly 183a has a locking member 251 that holds and releases spring 112 compressed by indicator rod 111 for ease of assembly of the device. Locking member 251 is slowly removed after assembly of the device to relax spring 112 and slowly compress the cartridge contents to avoid pressure shocks. Locking member 251 may be a nut on a threaded indicator rod or any other mechanism.

[0042] 8, subassembly 183b has an additional spring 112b that is weaker than spring 112 that compresses the drug solution in the cartridge after the device is assembled. Prior to injection, locking device 251 is removed, allowing spring 112 to fully pressurize the cartridge contents.

[0043] An alternative embodiment is shown in Figure 9. A latch 253 holds the spring 112 in compression and back for easy assembly. The latch 253 allows outward axial movement of the indicator 111 to relax the spring and compress the drug contents once the device is assembled.

[0044] 10 shows another embodiment of the invention. Module 186 is a combination of subassemblies 181 and 182, which contain the cartridge 102 that is supplied to the user and has needles 121 and 122 attached and held in place by needles 121 and 122.

[0045] FIG. 11 shows the assembled and ready to use auto-injector placed in a blister or pouch 488 and exposed to the gaseous environment for terminal sterilization, 489 indicates the sterilized area.

[0046] FIG. 12 shows the auto-injector assembled and ready for use, where indicator 111 includes an internal spring 112 and cap 122 that allows observation of the injection progress.

[0047] 13 shows the auto-injector assembled and ready for use, including an elastomeric needle cap 126 with an additional seal 128 to maintain the needle sterile. The use of the cap 126 and optionally the seal 128 allows for terminal sterilization without the use of a blister. For easier removal from the needle guard 131, the cap 126 is formed from an elastomeric material such as rubber.

[0048] A preferred embodiment of the present invention comprises: a cartridge subassembly 181 including a barrel 103 and a drug volume 107 retained by a movable plunger or stopper 104 and a crimped septum 105; a power supply and indicator subassembly 183 including a rear casing 110a holding the biasing means 112 and the indicator rod 111; a needle and needle guard subassembly 182 including a front casing 110b holding a needle shuttle 120 having an injection needle 121 and a septum needle 122, a needle guard 131 and a spring 132, a locking mechanism 135 to prevent the needle guard 131 from being pushed back a second time, and a means or shoulder 127 for holding the cartridge 102 in its correct position when the device is assembled, the assembled device being placed into a blister or pouch 488 and terminally sterilized; and A ready-to-use modular auto-injector comprising:

[0049] Another preferred embodiment of the present invention comprises: a cartridge subassembly 181 including a barrel 103 and a drug volume 107 retained by a movable plunger or stopper 104 and a crimped septum or cap 105; An indicator assembly 183 including a rear casing 110a and an indicator rod 111 including a spring 112 therein; a needle and needle guard subassembly 182 including a front casing 110b holding a needle shuttle 120 having an injection needle 121 and a septum needle 122, a needle guard 131 and a spring 132, a locking mechanism 135 to prevent the needle guard 131 from being pushed back a second time, a shoulder 127 to hold the cartridge 102 in its correct position when inserted, a seal 128 and a removable elastomeric needle cap 126 to keep the needle sterile; - reversible connection means 129 allowing reassembly of the device and assembly by the user; Equipped with The assembly 182 is supplied sterile and ready for use in a blister and / or supplied with a seal 128 and needle cap 126; A modular, ready-to-use, reusable auto-injector.

Claims

1. 1. An auto-injector comprising: an outer casing which holds a standard cartridge consisting of a barrel in which the drug contents are confined by a moveable plunger at one end and a seal and metal crimp at the other end; a biasing means for pressing the movable plunger of the cartridge to pressurize the drug contents; a needle shuttle held within said casing, the needle shuttle including two needles attached and connected to one another, a first needle being an injection needle and a second needle being a septum needle; means for holding said cartridge in its correct position when inserted; a needle guard carried by the outer casing and biased outwardly such that the needle is always covered by the needle guard; 1. An automatic injector comprising:

2. 10. The automatic injector of claim 1, further comprising a locking mechanism that prevents the needle guard from being pushed back a second time.

3. 3. The automatic injector of claim 1 or 2, further comprising an indicator rod attached to the movable plunger.

4. 4. The automatic injector of claim 3, wherein the indicator rod has a closed end containing the biasing means in the form of a spring therein, and the outer casing includes a transparent portion that allows monitoring of the progress and status of the injection progress.

5. Three subassemblies, namely: A cartridge subassembly; a power supply and indicator assembly; a needle and needle guard assembly; 5. The modular automatic injector of claim 1 , further comprising:

6. 6. The modular auto-injector of claim 4 or 5, wherein the cartridge subassembly comprises a barrel and a drug volume defined by a plunger and a crimped septum.

7. 7. The modular automatic injector of claim 4, wherein the power supply and indicator subassembly comprises a biasing means and an indicator rod carried within the rear casing.

8. 8. The modular automatic injector of claim 7, wherein the indicator rod is connected to the movable plunger for movement therewith.

9. 9. The modular automatic injector of claim 6, wherein the biasing means of the power supply and indicator subassembly is a spring further comprising a spring locking member.

10. 10. The modular automatic injector of claim 9, wherein the power supply and indicator subassembly further comprises an additional spring weaker than the spring for pressurizing cartridge drug contents prior to injection while the spring is locked by the spring locking member.

11. 11. The modular automatic injector of claim 5, wherein the needle and needle guard subassembly comprises a casing that holds a needle shuttle having an injection needle and a septum needle, a needle guard and a spring, a locking mechanism to prevent the needle guard from being pushed back a second time, and a shoulder to hold the cartridge in its correct position when inserted.

12. 12. The modular automatic injector of claim 10 or 11 for reassembly, wherein the needle and needle guard subassembly further comprises a seal and a needle cap, and the biasing means of the power source and indicator subassembly is an electric motor or a liquefied gas canister or a spring having means for recompressing itself, and the needle and needle guard subassembly and the power source and indicator subassembly are reversibly connected or hinged to each other by a bayonet fit or threads.

13. A method for assembling a modular auto-injector according to any one of claims 5 to 12, comprising the steps of: Inserting the cartridge into a needle and needle guard subassembly; connecting a power supply and indicator subassembly via a connecting means to the needle and needle guard subassembly with the cartridge inserted such that the medicament contents within the cartridge are pressurized; A method comprising:

14. Inserting the pre-assembled device into a blister or pouch; exposing the blister or pouch to terminal sterilization; The method of claim 13, further comprising:

15. 15. The method of claim 14, wherein the terminal sterilization is performed by ethylene oxide or nitrogen dioxide.

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