Compressed gas automatic injector

Abstract

A medicament delivery device, the medicament delivery device comprising: a housing; a container provided within the housing and configured to contain a medicament; the plunger is arranged in the container in a sliding manner; a plunger rod configured to urge the plunger through the container to dispense the medicament when the container contains the medicament; and a gas canister configured to travel with the plunger rod and contain compressed gas, where the gas canister is configured to release the compressed gas to drive the plunger rod to dispense the medicament out of the distal end of the container.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 586,999, filed on September 29, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure pertains to medical injections. Background Technology

[0003] Injection generally refers to the act of applying a liquid (such as a drug) into a patient's body tissues. Injecting a drug into a patient allows the drug to be absorbed relatively quickly. Summary of the Invention

[0004] This system and method can provide relatively high-volume injections of relatively high-viscosity pharmaceuticals. For example, in some embodiments, the autoinjector described herein provides a relatively easy-to-use device for injecting 5 ml (mL) volumes of pharmaceuticals with a viscosity of 3000 centipoise (cP) without requiring a relatively large amount of effort from the user. Typically, the gas canister included in the autoinjector provides sufficient injection force to inject the pharmaceuticals at the desired rate to meet the desired delivery time. Using a gas canister to provide a large injection force reduces the force that the user must apply to adequately deliver the injection. In some embodiments, the gas canister is included in the plunger rod to reduce the volume of the autoinjector. Generally, autoinjectors with reduced volume are easier for the user to manage and use than larger autoinjectors. In some embodiments, the autoinjector includes an interlocking device that prevents the autoinjector from firing until the desired time or action, for example, when the needle is attached to the distal end of the autoinjector's syringe barrel.

[0005] In one embodiment, the drug delivery device provided herein includes: a housing; a container disposed within the housing and configured to contain a drug; a plunger slidably disposed within the container; a plunger rod configured to push the plunger through the container to dispense the drug when the container contains the drug; and a gas canister configured to travel with the plunger rod and contain compressed gas, wherein the gas canister is configured to release the compressed gas to drive the plunger rod to dispense the drug from a distal end of the container.

[0006] Some of the implementation schemes presented in this article combine one or more of the following features.

[0007] In some implementations, the container holds 1 mL to 10 mL of the drug.

[0008] In some implementations, the container holds 2 mL to 8 mL of the drug.

[0009] In some implementations, the container holds 4 mL to 6 mL of the drug.

[0010] In some implementations, the container holds 5 mL of the drug.

[0011] In some implementations, the container holds 3 mL to 10 mL of the drug.

[0012] In some embodiments, the agent has a viscosity in the range of 1 cP to 3000 cP.

[0013] In some embodiments, the agent has a viscosity in the range of 1 cP to 2250 cP.

[0014] In some embodiments, the agent has a viscosity in the range of 1750 cP to 2750 cP.

[0015] In some embodiments, the agent has a viscosity in the range of 2000 cP to 2200 cP.

[0016] In some implementations, the agent has a viscosity of at least 2200 cP.

[0017] In some embodiments, the drug delivery device includes a button configured to activate an element configured to puncture a gas canister, wherein the gas canister is configured to release compressed gas upon puncture.

[0018] In some embodiments, the drug delivery device includes an interlocking device configured to prevent the element from puncturing the gas canister when the interlocking device is in the locked position.

[0019] In some implementations, the housing includes a cutout configured to receive the interlocking device when it is in the unlocked position.

[0020] In some implementations, the notch allows the interlocking device to bend radially when it is in the unlocked position.

[0021] In some implementations, the housing prevents the interlocking device from bending radially when it is in the locked position.

[0022] In some embodiments, the drug delivery device includes a needle configured to attach to the distal end of the container.

[0023] In some implementations, the interlocking device is configured to move to the unlocked position when the needle is attached to the drug delivery device.

[0024] In some implementations, the needles are size 20 to 21.

[0025] In some implementations, the needle size is smaller than 25.

[0026] In some implementations, the needles are size 18 to 25.

[0027] In some implementations, the needle has a length of at least 1.5 inches.

[0028] In some implementations, the needle has a length of 1.5 inches to 2 inches.

[0029] In some implementations, the needle has a length of 0.75 inches to 2.25 inches.

[0030] In some embodiments, the drug delivery device includes a needle protector configured to selectively cover the needle.

[0031] In some implementations, the housing includes at least one vent.

[0032] In some implementations, the gas cylinder is attached to the plunger rod.

[0033] In some implementations, the gas cylinder is housed within the plunger rod.

[0034] In another embodiment, this document provides a method for delivering a pharmaceutical agent contained in a container, the method comprising puncturing a gas canister to release compressed gas to drive a plunger rod and dispense the pharmaceutical agent, wherein the gas canister is configured to travel with the plunger rod.

[0035] Some of the implementation schemes provided in this article include one or more of the following features.

[0036] In some implementations, puncturing a gas canister includes pressing a button to activate an element configured to puncture the gas canister.

[0037] In some implementations, the method includes attaching a needle to the distal end of the container.

[0038] In some implementations, attaching the needle to the container moves the interlocking device from a locked position to an unlocked position, wherein the interlocking device prevents the button from moving in the locked position and allows the button to move in the unlocked position.

[0039] In some implementations, attaching the needle to the container includes screwing the needle seat onto the threads of the container retainer.

[0040] In some implementations, the method includes discharging compressed gas from the housing via one or more vents.

[0041] In some implementations, the gas cylinder is attached to the plunger rod.

[0042] In some implementations, the gas cylinder is housed within the plunger rod.

[0043] In one embodiment, this document provides a kit comprising a drug delivery device according to any of the above embodiments. The kit also includes a needle.

[0044] In some implementations, the needle is configured to be attached to the drug delivery device.

[0045] In some implementations, the kit includes multiple needles.

[0046] In some implementations, the needles have different sizes.

[0047] In some implementations, the needle has different shapes.

[0048] In some implementations, the needle is configured to be attached to the drug delivery device.

[0049] Details of one or more embodiments of the subject matter described herein are set forth in the following figures and description. Further features, objects, and advantages of the subject matter will become apparent from the description, figures, and claims. Attached Figure Description

[0050] Figure 1 An example autoinjector is shown.

[0051] Figure 2 The internal components of an example autoinjector are shown.

[0052] Figure 3 A gas cylinder is shown positioned inside a plunger.

[0053] Figures 4A to 4C An interlocking device is shown to prevent accidental firing of an autoinjector.

[0054] Figure 5 The needle attached to the autoinjector is shown.

[0055] Figure 6A and Figure 6B An interlocking device that allows the firing of an auto-injector is shown.

[0056] Figures 7A to 7C illustrate the movement of the interlocking device that allows the firing of the autoinjector.

[0057] Figure 8A and Figure 8B The firing of an auto-injector is shown.

[0058] Figure 9 The needle safety cap covering the needle is shown.

[0059] Figure 10 It is a table showing the delivery time and force of high-viscosity drugs.

[0060] The same reference numerals and names in the various figures indicate the same elements. Detailed Implementation

[0061] In some embodiments, the system and method provided herein provide relatively high-volume injection of relatively high-viscosity pharmaceutical agents and relatively large injection force, while reducing the force applied by the user to adequately deliver the injection. In some embodiments, the system and method also prevent the autoinjector from firing until a desired time or action, such as when the needle is attached to the autoinjector.

[0062] Figure 1 An example autoinjector 100 is shown, comprising a housing 102, a button 104 on a proximal end 106 of the housing 102, and a needle holder 108 attached to a distal end 110 of the housing 102. The needle holder 108 includes a needle safety device 112 that selectively covers a needle 114 of the needle holder 108. For example, a user can bend the needle safety device 112 about a hinge 116 to move the needle safety device 112 over the needle 114. The needle 114 is covered by a needle cap 118, which the user removes before using the autoinjector 100. In some embodiments, the button 104 is located at other locations on the autoinjector. For example, the button 104 may be a side button located somewhere between the proximal end 106 and the distal end 110 of the housing 102. In some embodiments, the button is a lever that rotates relative to the housing 102 to activate the device. In some embodiments, the housing 102 includes a flange configured to receive a user's finger.

[0063] The housing 102 includes a label 122 that provides information about the autoinjector 100. For example, in some embodiments, the label 122 includes pharmaceutical information such as the type of pharmaceutical agent, dosage, delivery time of the dosage, expiration date of the pharmaceutical agent, batch or lot number, information identifying the autoinjector 100 as a single-use autoinjector, and company information. Optionally, the housing 102 may not include the label 122.

[0064] The housing 102 also includes a window 120 through which a user can see the medication contained within the autoinjector 100, for example, the medication contained in the container of the autoinjector 100 (see discussion below). In some embodiments, the window 120 helps the user determine whether the autoinjector 100 has been used. Before using the autoinjector 100, the user can see through the window 120 to determine whether there is medication inside the autoinjector 100, for example, to determine that the autoinjector has not been used. In some embodiments, during use of the autoinjector 100, the user can see through the window 120 to determine whether the volume of medication in the autoinjector 100 is decreasing. In some embodiments, after use of the autoinjector 100, the user can see through the window 120 to determine that there is no medication in the autoinjector 100, for example, to determine that the autoinjector 100 has been used. In some embodiments, the user can see the plunger through the window 120 and determine that the autoinjector 100 has been used. In some embodiments, the user determines that the autoinjector has been used because the button 104 remains in the use position.

[0065] In some embodiments, the autoinjector 100 is used for intramuscular injection, which is injected into the patient's muscle. Intramuscular injection may involve a needle that is longer and / or thicker than that used for subcutaneous injection, which is guided into the adipose tissue between the patient's skin and muscle. As an example, in some embodiments, the needle 114 is a 20 gauge and 1.5 inches long. As another example, in some embodiments, the needle 114 is a 27 gauge and 0.5 inches long. Injecting a drug with a longer needle may involve a relatively large injection force compared to injecting the drug with a shorter needle, for example, when the drug is a high-volume, high-viscosity drug. Similarly, injecting a drug with a thinner needle may involve a relatively large injection force compared to injecting the drug with a wider needle. For example, intramuscular injection of high-volume, high-viscosity drugs may be relatively difficult due to the relatively large injection force and delivery time involved. In some embodiments, the autoinjector 100 (and other autoinjectors described herein) provides sufficient injection force to inject relatively high-volume, relatively high-viscosity drugs through a needle configured for intramuscular injection within the delivery time described below. The needles can be available in various sizes for intramuscular injection (e.g., 20-21 gauge, smaller than 25 gauge, 18-25 gauge, etc.). The needles can also be available in various lengths for intramuscular injection (e.g., at least 1.5 inches, 1.5-2 inches, 1-2 inches, 0.75-2.25 inches, etc.). In some embodiments, the kit includes an autoinjector 100 and multiple needles. The multiple needles can be of different sizes, gauges, shapes, etc., and the user can select a needle suitable for a specific injection. The user can attach the selected needle to the autoinjector 100 and use the autoinjector 100 as described herein.

[0066] Figure 2 An example autoinjector 200 is shown, which can provide a relatively large injection force to inject a relatively high volume, relatively high viscosity drug (e.g., similar to...) through a needle 234 configured for intramuscular injection. Figure 1 An autoinjector 200 includes a housing 202, a container 204 held within the housing 202, a plunger 206 slidably disposed within the container 204, a piston 208, and a gas canister 210. The container 204 is held in a container holder 212 connected to the housing 202. The container 204 may contain a medication (not shown), and the autoinjector 200 may be activated by a user to dispense the medication from the container 204. For example, the user may press a button 214 on the proximal end 226 of the housing 202 to puncture the gas canister 210, thereby releasing compressed gas from the gas canister 210. The compressed gas may include, for example, argon, carbon dioxide, krypton, xenon, etc. The button 214 is biased in the proximal direction by a button spring 218. The button 214 activates a firing pin 216, which punctures the end of the gas canister 210, as discussed further below. The compressed gas expands, driving the piston 208 against the plunger 206 and through the container 204. As the plunger 206 moves distally through the container 204, the medication is dispensed through the needle 234. When the medication is a relatively high-viscosity medication (e.g., 3000 cP), the plunger 206 can provide a relatively large force (e.g., 380 Newtons (N), which may be a time-averaged force) to dispense the medication from the needle 234 within the desired delivery time (e.g., within 50 seconds). A rapidly expanding gas (e.g., released from the gas canister 210) can provide the necessary force, for example, for intramuscular injection. For example, in some embodiments, such as those described with respect to the autoinjector 200, a rapidly expanding gas can provide a greater force than that provided in an autoinjector using a drive spring.

[0067] As an example, in some embodiments, container 204 has an internal volume that can hold 5 mL of the medicine. In some embodiments, container 204 can hold multiple volumes of medicine (e.g., 1 mL to 10 mL of medicine, 2 mL to 8 mL of medicine, 4 mL to 6 mL of medicine, 3 mL to 10 mL of medicine, etc.).

[0068] In the autoinjector 200, a gas canister 210 is disposed within a piston 208. For example, the piston 208 includes, for instance, a plunger rod portion 220 and a canister retainer portion 222. The plunger rod portion 220 is configured to interact with a plunger 206 to drive the plunger 206 through a container 204. This interaction may include inserting a distal end of the plunger rod portion 220 into a cavity defined within the plunger 206. The canister retainer portion 222 provides a recess to receive the gas canister 210 within it. A seal 224 seals the connection between the plunger rod portion 220 and the canister retainer portion 222, and seals the other end of the canister retainer portion 222. When the gas canister 210 releases compressed gas, the seal 224 prevents the released gas from leaving the rest of the piston 208. The released gas is directed proximally such that the force of the expanding gas drives the piston 208 distally to dispense the medication. Pressure vessel 228 is connected to container retainer 212 and keeps piston 208 aligned with container 204. Released gas expands within pressure vessel 228 to drive piston 208 and plunger 206 into container 204.

[0069] Containing the gas canister 210 within the piston 208 reduces the volume of the autoinjector 200. For example, if the gas canister were not contained within the piston, the housing would need to extend beyond the piston 208 by at least the length of the gas canister 210 to provide sufficient space for it. Conversely, because the length of the gas canister 210 is incorporated into the piston 208, the housing 202 does not need to extend beyond the piston 208 by the additional length of the gas canister 210. In some embodiments, the gas canister is partially (e.g., at least partially) contained within the piston. Reducing the volume of the autoinjector 200 is advantageous because an autoinjector with a reduced volume is easier for the user to manage and use than a bulkier, larger autoinjector.

[0070] The autoinjector 200 also includes a needle hub 230 detachably connected to the distal end of the container 204. The needle hub 230 includes a needle safety device 232 that can selectively cover the needle hub 230 (e.g., similar to...). Figure 1 The needle 234 is located in the needle hub 108. The needle 234 is covered by a needle cap 236, which is removed by the user before using the autoinjector 200. The needle hub 230 also includes a needle hub seal 238 that seals the connection between the needle hub 230 and the container 204. The needle hub seal 238 prevents leakage between the container 204 and the needle hub 230.

[0071] In some embodiments, the autoinjector cap 240 is attached to the distal end of the housing 202 before the needle hub 230 is attached to the distal end of the container 204. For example, to use the autoinjector 200, the user can remove the autoinjector cap 240 from the distal end of the autoinjector 200 and then attach the needle hub 230 to the distal end of the container 204. The user can then press button 214 to dispense the medication, as discussed above. In some embodiments, the autoinjector cap 240 includes a Luer point cap 242 that seals the distal end of the container 204. The Luer point cap 242 reduces (e.g., prevents) leakage from the distal end of the container 204 before using the autoinjector 200. In some embodiments, the Luer point cap 242 is configured to be releasably attached to a corresponding Luer tip disposed on the distal end of the container 204.

[0072] The autoinjector 200 may also include an interlocking device 244 to prevent the button 214 from being pressed before the needle hub 230 is attached to the container 204. The interaction between the interlocking device 244 and the button 214 will be described in more detail below. Before use of the device, the interlocking device 244 is biased in a locked position in the distal direction by an interlocking device spring 246. For example, the interlocking device spring 246 may be disposed between the housing 202 and the interlocking device 244 to bias the interlocking device 244 in the distal direction. When the interlocking device 244 is in the locked position, the interlocking device 244 prevents the button 214 from being pressed, as discussed further below. Because the interlocking device 244 prevents the button 214 from being pressed, the firing pin 216 cannot pierce the gas canister 210 to dispense the medication. When the needle hub 230 is attached to the container 204, the needle hub 230 moves the interlocking device 244 into the unlocked position against the bias of the interlocking device spring 246. When the interlocking device 244 is in the unlocked position, it allows the button 214 to be pressed, as discussed further below. Because the interlocking device 244 allows the button 214 to be pressed (after the needle holder 230 is attached to the container), the firing pin 216 is able to pierce the gas canister 210 to dispense the medication through the needle holder 230.

[0073] Figure 3 An example of a pressure vessel 300 is shown. The pressure vessel 300 can be similar to... Figure 2 Pressure vessel 228. Pressure vessel 300 is connected to vessel retainer 302 to keep piston 304 aligned with vessel 306. Piston 304 includes a gas canister 308 disposed within piston 304. For example, piston 304 includes a plunger rod portion 310 and a canister portion 312. Plunger rod portion 310 is configured to interact with plunger 314 to drive plunger 314 through vessel 306. Canister portion 312 provides a recess to receive gas canister 308 within canister portion 312.

[0074] In some embodiments, the pressure vessel 300 includes one or more piston seals 316 that seal the connection between the plunger rod portion 310 and the tank portion 312. The piston seal 316 may be formed of, for example, nitrile rubber (e.g., having a Shore A hardness of 70). The piston seal 316 prevents gas released from the gas tank 308 from escaping via the connection between the plunger rod portion 310 and the tank portion 312. In some embodiments, the one or more piston seals 316 are static seals. For example, a static seal can form a seal between components that do not move relative to each other. In some embodiments, there is no seal between the plunger rod portion 310 and the tank portion 312. For example, the plunger rod portion 310 and the tank portion 312 may be formed as a single piece, such that there is no connection between the plunger rod portion 310 and the tank portion 312 for gas venting. When the plunger rod portion 310 and the canister portion 312 are two connected parts, one or more piston seals 316 can prevent gas from escaping through the connection between the plunger rod portion 310 and the canister portion 312.

[0075] In some embodiments, the pressure vessel 300 also includes one or more lip seals 318 that seal the area between the piston 304 and the pressure vessel 300. The lip seals 318 may be formed of, for example, nitrile rubber (e.g., having a Shore A hardness of 75 or 85). The lip seals 318 prevent gas from escaping around the piston 304 and entering the vessel 306. Keeping the expanding gas close to the piston 304 drives the piston 304 distally. If gas could escape around the piston 304, the piston 304 might not be driven distally sufficiently to dispense the agent. The lip seals 318 keep the expanding gas close to the piston 304 by sealing the area between the piston 304 and the pressure vessel 300. In some embodiments, the one or more lip seals 318 are dynamic seals. For example, dynamic seals can form a seal between components that move relative to each other.

[0076] In some embodiments, the pressure vessel 300 also includes one or more striker seals 320 that seal the area between the pressure vessel 300 and a striker 322 that punctures the gas canister 308. The striker seal 320 may be made of, for example, an elastomer (e.g., a fluoropolymer, such as Viton). ™It is formed of rubber (with a Shore A hardness of 70). The striker seal 320 may be formed of rubber. The striker seal 320 prevents gas from escaping through the rear of the pressure vessel 300. Retaining the expanding gas within the pressure vessel 300 provides a defined volume for the gas to expand therein. Providing a defined volume for the gas to expand therein controls the force exerted by the expanding gas on the piston 304. For example, if the expanding gas is not limited to a defined volume, the gas may not exert the desired injection force on the piston 304. The striker seal 320 can retain the expanding gas within a defined volume of the pressure vessel 300 by sealing the area between the pressure vessel 300 and the striker 322. In some embodiments, one or more striker seals 320 are dynamic seals.

[0077] Figures 4A to 4C An autoinjector 200 is shown, wherein the interlocking device 244 is in the locked position, and the cap 240 is removed by the user before using the autoinjector 200. Removing the cap 240 from the autoinjector 200 allows a needle hub (not shown) to be attached to the autoinjector 200, as discussed above.

[0078] Interlocking device 244 is biased in a locked position in the distal direction by interlocking device spring 246. For example, interlocking device spring 246 may be disposed between housing 202 and interlocking device 244 to bias interlocking device 244 in the distal direction. When interlocking device 244 is in the locked position, interlocking device 244 prevents button 214 from being pressed. For example, interlocking device 244 includes interlocking device latch 248 that interacts with button latch 250 to prevent button 214 from being pressed. When a user attempts to press button 214, for example, as Figure 4B As indicated by arrow F, the interlocking device latch 248 interacts with the pushbutton latch 250, preventing the pushbutton 214 from moving to a position sufficient to cause the firing pin 216 to puncture the gas canister 210. For example, Figure 4C A closer view of the firing pin 216, which cannot pierce the gas canister 210, is shown.

[0079] In some implementations, when the interlocking device 244 is in the locked position, the button 214 can move a relatively small distance (e.g., 2 mm). This relatively small distance is still insufficient for the firing pin 216 to pierce the gas canister 210. The button spring 218 can bias the button 214 away from the interlocking device 244 in a proximal direction.

[0080] In some embodiments, the pressure vessel 228 includes a protrusion 252 to prevent the push-button latch 250 from biasing inward away from the interlocking device latch 248 and from moving past the interlocking device latch 248 when the interlocking device 244 is in the locked position. In some embodiments, the push-button latch 250 is not flexible and cannot be biased inward, and the protrusion 252 is optional.

[0081] Figure 5 A needle hub 230 attached to an autoinjector 200 is shown. For example, a user can attach the needle hub 230 to the autoinjector 200. Attaching the needle hub 230 to the autoinjector 200 moves the interlocking device from a locked position to an unlocked position, as discussed above. In the example shown, the needle hub 230 is rotated to be attached to the autoinjector 200, for example, via a threaded connection. In some embodiments, the needle hub 230 is attached to the autoinjector via other connections (e.g., bayonet connections, snap-fit ​​connections, etc.). The needle hub 230 can be connected to the container 204 of the autoinjector 200, as discussed above. Rotation of the needle hub 230 is indicated clockwise by arrow 254. In some embodiments, the needle hub 230 is rotated 90 degrees. o The needle hub 230 is attached to the autoinjector 200. The needle hub 230 can be designed to rotate by multiple amounts (e.g., 180 degrees). o 270 o 360 o (etc.) to attach the needle hub 230 to the autoinjector 200.

[0082] Figure 6A and Figure 6B An autoinjector 200 with an interlocking device 244 is shown, which has been moved to the unlocked position due to the attachment of the needle hub 230. As discussed above, attaching the needle hub to the autoinjector moves the interlocking device proximally to the unlocked position. The proximal movement of the interlocking device 244 is indicated by arrow 258. When the interlocking device 244 is in the unlocked position, the button 214 can be pressed, causing the firing pin 216 to pierce the gas canister 210 to dispense the medication. Figure 6B As shown, the user can press button 214, causing button latch 250 of button 214 to move through interlocking device latch 248. The pressing of the button is indicated by arrow 260. When button 214 is pressed, button spring 218 is pressed down, and button latch 250 moves through interlocking device latch 248. Button latch 250 can move through interlocking device latch 248 because interlocking device latch 248 is radially deflected outward through cutout 256 in housing 202. The radial deflection of interlocking device latch 248 is indicated by arrow 262. When interlocking device 244 moves proximally to the unlocked position, interlocking device latch 248 aligns with cutout 256 in housing 202 to allow interlocking device latch 248 to deflect outward. When the interlocking device latch 248 is radially outwardly deflected through the cut 256, the push button latch 250 has space to move past the interlocking device latch 248, allowing the firing pin 216 to pierce the gas cylinder 210. For example, Figure 6BA striking pin 216 is shown piercing the gas canister 210. As discussed above, expanding gas can provide a large injection force to inject high-volume, high-viscosity drugs through a needle configured for intramuscular injection.

[0083] Figures 7A to 7C illustrate the interlocking device latch 248, the push-button latch 250, and the cutout 256 in the housing 202 when the interlocking device 244 is in the locked position and when the interlocking device 244 is in the unlocked position. Figure 7A shows the interlocking device latch 248, the push-button latch 250, and the cutout 256 when the interlocking device 244 is in the locked position (e.g., before the needle hub 230 is attached to the autoinjector 200). When the interlocking device 244 is in the locked position, the interlocking device latch 248 is not aligned with the cutout 256 in the housing 202. Therefore, the housing 202 prevents the interlocking device latch 248 from deflecting radially outward. Because the interlocking device latch 248 cannot deflect radially outward, the interlocking device latch 248 prevents the push-button latch 250 from moving distally.

[0084] Figure 7B illustrates the interlocking latch 248, button latch 250, and cutout 256 when the interlocking device 244 is in the unlocked position. For example, as discussed above, when the needle hub 230 is attached to the autoinjector 200, the interlocking device 244 moves proximally from the locked position to the unlocked position. This proximal movement of the interlocking device 244 to the unlocked position aligns the interlocking device latch 248 with the cutout 256 in the housing 202. When the interlocking device latch 248 is aligned with the cutout 256, the interlocking device latch 248 is capable of radially outward deflection. The tilted engagement between the button latch 250 and the interlocking device latch 248 causes the interlocking device latch 248 to deflect radially outward. This outward deflection of the interlocking device latch 248 is indicated by arrow 262. Because the interlocking device latch 248 is aligned with the cutout 256, the housing 202 does not prevent the interlocking device latch 248 from radially deflecting outward. Because the interlocking device latch 248 can be radially outward, the interlocking device latch 248 does not prevent the button latch 250 from moving to the distal side.

[0085] Figure 7C shows the interlocking latch 248, the button latch 250, and the notch 256 as the button latch 250 moves past the interlocking latch 248. Because the needle hub 230 is connected to the autoinjector 200, the interlocking latch 248 is aligned with the notch 256. The button latch 250 passes through the interlocking latch 248, and the movement of the button latch 250 is indicated by arrow 264. Due to the movement of the button latch 250, the interlocking latch 248 now approaches the button latch 250. The interlocking latch 248 prevents the button latch 250 from moving proximally after injection begins. Preventing the button latch 250 from moving proximally prevents the button 214 from moving proximally after injection begins. The engagement between the interlocking latch 248 and the button latch 250 is not an oblique engagement, so the button latch 250 does not cause the interlocking latch 248 to deflect radially outward. When the button latch moves past the interlocking device latch 248, the firing pin 216 punctures the gas canister 210, as discussed above. As discussed above, the expanding gas can provide a large injection force to inject high-volume, high-viscosity drugs through a needle configured for intramuscular injection.

[0086] Figure 8A and Figure 8B An autoinjector 200 dispensing medication is shown after the button latch 250 moves through the interlocking device latch 248. As discussed above and Figure 8A As shown, the firing pin 216 punctures the gas canister 210. Puncture of the gas canister 210 causes compressed gas to expand into the pressure vessel 228, driving the piston 208 distally to dispense the agent, as discussed above. The rapid expansion of the compressed gas provides sufficient injection force to inject a high volume, high viscosity liquid within the desired injection time. Figure 8B The image shows piston 208 moving into container 204 to dispense the medication. The movement of piston 208 is indicated by arrow 268.

[0087] In some embodiments, the autoinjector 200 includes a dose-starting click feature 266 that produces an audible sound when the firing pin 216 punctures the gas canister 210. For example, the click feature 266 can emit an audible sound when the piston 208 compresses it. The audible sound can help, for example, warn the user that the gas canister 210 has been punctured. In some embodiments, the click feature 266 can emit an audible sound when the dose has been fully dispensed. In some embodiments, the click feature 266 can emit a continuous clicking sound during dose dispensing.

[0088] In some embodiments, the autoinjector 200 includes a plurality of vents 270 that allow compressed gas to escape from the autoinjector 200 after the dose has been fully dispensed. For example, the pressure vessel 228, interlocking device 244, and housing 202 may include vents 270. The position of the vents 270 allows compressed air to push the piston 208 through the container 204, and the vents 270 do not allow gas to escape during dispensing. For example, the vents 270 are not accessible to expanding gas until the piston has moved to the distal end of the dose position. Gas can only reach the vents 270 until the piston 208 reaches the distal end of the dose position.

[0089] Figure 9 The needle holder 230 is shown after the dose has been dispensed, as described above. In some embodiments, the user can move the needle safety device 232 to cover the needle 234 by bending it about a hinge. The movement of the needle safety device 232 over the needle 234 is indicated by arrow 272. Covering the needle 234 with the needle safety device 232 prevents accidental acupuncture after the dose has been dispensed.

[0090] Figure 10 A table showing example forces and delivery times for delivering high-volume, high-viscosity pharmaceutical agents using the aforementioned autoinjector 200 is provided. The high-viscosity pharmaceutical agent can have a viscosity of, for example, 2250 cP. In some embodiments, the agent can have a variety of viscosities (e.g., 1 cP to 3000 cP, 1 cP to 2250 cP, 1750 cP to 2750 cP, 2000 cP to 2500 cP, at least 2200 cP, etc.). The viscosity of the agent can also vary depending on the temperature of the agent. For example, the viscosity of the agent at 18°C ​​can be higher than that at 28°C. In one example, the viscosity of the agent can be 2220 cP at 18°C, 1330 cP at 23°C, and 800 cP at 28°C. The force provided by the compressed gas can be designed to meet the desired delivery time for varying the viscosity of the agent. Figure 10The values ​​in the table are exemplary values ​​for a drug with a viscosity of 2220 cP at 18°C, 1330 cP at 23°C, and 800 cP at 28°C. Calculate values ​​for a needle length of 2 inches, a needle gauge of 20, a drug volume of 5 mL, and a container radius of 5.93 mm. A relatively low injection force (e.g., an average force of 140 N) provides a maximum delivery time of 142 seconds (e.g., when the drug viscosity is 2220 cP at 18°C) and a minimum delivery time of 50 seconds (e.g., when the drug viscosity is 800 cP at 28°C). A relatively moderate injection force (e.g., an average force of 230 N) provides a maximum delivery time of 83 seconds (e.g., when the drug viscosity is 2220 cP at 18°C) and a minimum delivery time of 30 seconds (e.g., when the drug viscosity is 800 cP at 28°C). A relatively high injection force (e.g., an average force of 380 N) provides a maximum delivery time of 50 seconds (e.g., when the viscosity of the agent is 2220 cP at 18°C) and a minimum delivery time of 18 seconds (e.g., when the viscosity of the agent is 800 cP at 28°C). Therefore, if the desired maximum delivery time is 50 seconds, the gas canister should apply an average injection force of 380 N to meet the desired delivery time.

[0091] Several embodiments have been described. However, it should be understood that various changes and modifications may be made without departing from the spirit and scope of this disclosure. Therefore, other embodiments are within the scope of the following claims.

Claims

1. A drug delivery device, comprising: case; A container, which is disposed within the housing and configured to contain a pharmaceutical agent; A plunger, which is slidably disposed within the container; A plunger rod configured to push a plunger through the container to dispense the medication when the container contains the medication; and A gas canister configured to travel with the plunger rod and contain compressed gas, wherein the gas canister is configured to release the compressed gas to drive the plunger rod to dispense the agent from the distal end of the container.

2. The drug delivery device according to claim 1, wherein the container contains 1 mL to 10 mL of drug.

3. The drug delivery device according to claim 1 or claim 2, wherein the container contains 2 mL to 8 mL of drug.

4. The drug delivery device according to any one of claims 1 to 3, wherein the container contains 4 mL to 6 mL of drug.

5. The drug delivery device according to any one of claims 1 to 4, wherein the container contains 5 mL of drug.

6. The drug delivery device according to any one of claims 1 to 2, wherein the container contains 3 mL to 10 mL of drug.

7. The drug delivery device according to any one of claims 1 to 6, wherein the drug has a viscosity in the range of 1 cP to 3000 cP.

8. The drug delivery device according to any one of claims 1 to 7, wherein the drug has a viscosity in the range of 1 cP to 2250 cP.

9. The drug delivery device according to any one of claims 1 to 8, wherein the drug has a viscosity in the range of 1750 cP to 2750 cP.

10. The drug delivery device according to any one of claims 1 to 9, wherein the drug has a viscosity in the range of 2000 cP to 2200 cP.

11. The drug delivery device according to any one of claims 1 to 10, wherein the drug has a viscosity of at least 2200 cP.

12. The drug delivery device according to any one of claims 1 to 11, further comprising a button configured to activate an element configured to puncture the gas canister, wherein the gas canister is configured to release the compressed gas upon puncture.

13. The drug delivery apparatus according to any one of claims 1 to 12, further comprising an interlocking device configured to prevent the element from puncturing the gas canister when the interlocking device is in a locked position.

14. The drug delivery device of claim 13, wherein the housing includes a cutout configured to receive the interlocking device when the interlocking device is in the unlocked position.

15. The drug delivery device of claim 14, wherein the cut allows the interlocking device to bend radially when the interlocking device is in the unlocked position.

16. The drug delivery device according to any one of claims 13 to 15, wherein when the interlocking device is in the locked position, the housing prevents the interlocking device from bending radially.

17. The drug delivery device according to any one of claims 1 to 16, further comprising a needle configured to be attached to a distal end of the container.

18. The drug delivery device of claim 17, wherein the interlocking device is configured to move to an unlocked position when the needle is attached to the drug delivery device.

19. The drug delivery device according to claim 17 or claim 18, wherein the needle is a size 20 to 21.

20. The drug delivery device according to claim 17 or claim 18, wherein the needle is smaller than size 25.

21. The drug delivery device according to claim 17 or claim 18, wherein the needle is of size 18 to 25.

22. The drug delivery device according to any one of claims 17 to 21, wherein the needle has a length of at least 1.5 inches.

23. The drug delivery device according to any one of claims 17 to 21, wherein the needle has a length of 1.5 inches to 2 inches.

24. The drug delivery device according to any one of claims 17 to 21, wherein the needle has a length of 0.75 inches to 2.25 inches.

25. The drug delivery device according to any one of claims 17 to 24, further comprising a needle protector configured to selectively cover the needle.

26. The drug delivery device according to any one of claims 1 to 25, wherein the housing includes at least one vent.

27. The drug delivery device according to any one of claims 1 to 26, wherein the gas canister is attached to the plunger rod.

28. The drug delivery device according to any one of claims 1 to 27, wherein the gas canister is disposed within the plunger rod.

29. A method for delivering a pharmaceutical agent contained in a container, the method comprising: The gas canister is punctured to release compressed gas to drive a plunger rod and dispense the medication, wherein the gas canister is configured to travel with the plunger rod.

30. The method of claim 29, wherein piercing the gas canister comprises pressing a button to activate an element configured to pierce the gas canister.

31. The method of claim 29 or claim 30, further comprising attaching the needle to the distal end of the container.

32. The method of claim 31, wherein attaching the needle to the container moves the interlocking device from a locked position to an unlocked position, wherein the interlocking device prevents the button from moving in the locked position and allows the button to move in the unlocked position.

33. The method of claim 31 or claim 32, wherein attaching the needle to the container comprises screwing the needle seat onto the threads of the container retainer.

34. The method according to any one of claims 29 to 33, further comprising discharging the compressed gas from the housing via one or more vents.

35. The method according to any one of claims 29 to 34, wherein the gas canister is attached to the plunger rod.

36. The method according to any one of claims 29 to 35, wherein the gas canister is disposed within the plunger rod.

37. A reagent kit comprising: The drug delivery device according to any one of claims 1 to 28; and Needle.

38. The kit of claim 37, wherein the needle is configured to attach to the drug delivery device.

39. The kit of claim 37, wherein the kit comprises a plurality of needles.

40. The kit of claim 39, wherein the needles have different sizes.

41. The kit according to claim 39 or claim 40, wherein the needle has a different shape.

42. The kit according to any one of claims 37 to 41, wherein the needle is configured to attach to the drug delivery device.

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