CN118267231A

CN118267231A - Drug delivery device

Info

Publication number: CN118267231A
Application number: CN202311804306.8A
Authority: CN
Inventors: 刘继东; 杨强; 李力; 那君
Original assignee: Shenyang Xingqi Pharmaceutical Co Ltd
Current assignee: Shenyang Xingqi Pharmaceutical Co Ltd
Priority date: 2022-12-30
Filing date: 2023-12-25
Publication date: 2024-07-02
Also published as: WO2024140825A1; CN222032828U

Abstract

There is provided a drug delivery device comprising: a housing provided with a space for mounting a cartridge having a hollow accommodating space in which a medicine to be administered is preloaded; a push rod including a push rod distal end which is accommodated in the hollow accommodation space of the cartridge and is movable in an axial direction with respect to the cartridge to discharge air or medicine in the hollow accommodation space of the cartridge; a vent assembly configured to cause the pushrod to move distally in an axial direction relative to the cartridge to vent air within the hollow accommodating space; an injection assembly configured to cause the pushrod to move distally in an axial direction relative to the cartridge to expel a drug within the hollow containing space; and a force-relieving assembly configured to cause the ram to move in a proximal direction opposite the distal direction after the ram is moved distally by the vent assembly and/or the injection assembly.

Description

Drug delivery device

The present application claims priority from chinese patent application No.202211727431.9 entitled "drug delivery device" filed on 12 months 30 of 2022, the disclosure of which is incorporated herein in its entirety as part of the present application.

Technical Field

The present disclosure relates to drug delivery devices, in particular to drug delivery devices preloaded with a drug.

Background

The eye is one of the most sensitive organs of the human body. The three layers of the eye wall are, in order from the outside to the inside, the adventitia (cornea, sclera), the media (iris, ciliary body, and choroid), and the intima (retina). Ocular administration is the primary means of ophthalmic treatment, and presents difficulties in clinical fundus administration due to the high sensitivity of the eye and the unique physiological barriers (including cornea and conjunctival barrier, blood aqueous humor barrier, blood retinal barrier).

The traditional eye administration type is a local eye drop and an eye ointment, and the two common preparations have the advantages of solution preparation and convenient use and are easy to be accepted by patients. However, the eye drops have low bioavailability and short acting time, and most of the liquid medicine is discharged from lacrimal passages after administration and can cause systemic toxicity after being absorbed by nose and pharynx; the ointments contain problems of transparency and refractive index of the matrix, which tend to cause patient fogging. In order to achieve the dosage of the medicine at the rear end of the eye, the subconjunctival injection, the peribulbar injection and the retrobulbar injection are applied to clinic in the beginning of the 20 th century, and the mode of administration is the most direct method for conveying the medicine to the tissue at the rear end of the eye, so that the medicine can be quickly gathered near retina and vitreous body, the concentration of the medicine in the tissue at the rear end of the eye can reach higher level, the effect is quick, the side effect is small, and the influence on the whole body is small. At present, the traditional Chinese medicine composition is mainly used for treating age-related macular degeneration (AMD), retinal Vein Occlusion (RVO), diabetic eye diseases, posterior uveitis and other diseases.

The human eyeball volume is about 5ml, wherein the anterior chamber is about 0.5ml, and the posterior chamber is about 4.5ml. In addition to the drug treatment effect and injection site, accurate administration of trace amounts is also a major concern when administering ocular fundus. The larger the volume of fundus administered, the greater the intraocular pressure is affected, and the greater the damage to the ocular ball, while the accuracy of drug dosage is difficult to achieve with conventional syringes when administered in small volumes. For example, currently, products commonly used for ocular fundus administration are mostly solid implants and liquid injections. Wherein, the solid implant is to inject the solid medicine into the eye directly through the sclera, which has great damage to the eyeball; liquid formulations are typically administered in an amount of 50 microliters and are administered directly by aspiration through a conventional syringe. Whereas for aqueous solutions with doses less than 25 microliters, especially for viscous medical solutions, the accuracy of the fundus dose is difficult to achieve using conventional syringes.

Therefore, there is a need in clinical applications for a drug delivery device that is capable of accurately and quantitatively administering a drug, particularly for accurate and quantitative administration of viscous medical fluids. In particular, there is a need for an ocular drug delivery device that meets the high demands of the eye.

Disclosure of Invention

The invention aims to solve the technical problem of providing a drug delivery device which can be used for accurately and quantitatively delivering drugs, particularly for ocular drug delivery and can be used for accurately and quantitatively delivering viscous liquid medicine.

The present disclosure describes at least the following technical solutions:

technical solution 1, a drug delivery device, comprising:

A housing provided with a space for mounting a cartridge having a hollow accommodating space for preloading a drug to be administered;

A push rod including a push rod distal end which is accommodated in the hollow accommodation space of the cartridge and is movable in an axial direction with respect to the cartridge to discharge air or medicine in the hollow accommodation space of the cartridge;

A vent assembly configured to cause the pushrod to move distally relative to the cartridge in the axial direction to vent air within the hollow accommodating space;

An injection assembly configured to cause distal movement of the pushrod relative to the cartridge in the axial direction to expel a drug within the hollow containment space; and

A force-relieving assembly configured to cause the ram to move in a proximal direction opposite the distal direction after the ram is moved distally by the vent assembly and/or the injection assembly.

In the above-described aspect, the venting assembly causes the pushrod to move distally to vent, and the force-relieving assembly is then able to cause the pushrod to retract proximally. Additionally or alternatively, the injection assembly causes the ram to move distally to inject the medical fluid, and the force-relieving assembly can then cause the ram to retract proximally. Since the push rod is also retracted proximally after distal movement, more than the intended dose of drug is prevented from being expelled from the cartridge upon venting and/or injection. Therefore, the injection accuracy is improved, especially for drugs with a large viscosity.

The drug delivery device according to claim 2, wherein,

The venting assembly includes a venting button configured to drive the pushrod to move distally relative to the cartridge in the axial direction by a first motion to vent air within the hollow receiving space.

The drug delivery device according to claim 3, wherein,

The venting button is further configured to pass a second movement following the first movement to allow the pushrod to move proximally relative to the cartridge; and

The force relief assembly includes a first force relief assembly configured to cause the pushrod to move proximally relative to the cartridge during a second movement of the venting button.

In the technical scheme, a user can control the push rod to move distally and move proximally by operating the exhaust button to perform first movement and second movement, so that the exhaust and the force-unloading operation after the exhaust are realized. Thus, the operability of the drug delivery device is improved.

The drug delivery device of claim 4, wherein the first movement of the venting button is a distal axial movement.

Claim 5, the drug delivery device of claim 3, wherein the second movement of the venting button is a rotation about a longitudinal axis and a proximal axial movement.

By setting the first movement as a distal axial movement and/or setting the second movement as a rotation about a longitudinal axis and a proximal axial movement, the operability and convenience for the user is improved. Claim 6, the drug delivery device according to claim 2, wherein,

The injection assembly comprises:

an injection spring configured to be compressed in response to the first movement of the vent button; and

A trigger button configured to be actuated to release energy stored by the injection spring as a result of compression, causing the push rod to move distally, expelling the drug within the hollow containment space.

Due to the arrangement of the injection spring and the trigger button, the injection operation of the medicine in the hollow accommodating space can be started by only actuating the trigger button through the energy stored by the injection spring. Thus, the operability and convenience of the user are improved.

Claim 7, the drug delivery device according to claim 6, further comprising

A sliding ejector configured to releasably limit distal movement of the push rod, and the limit is releasable by actuation of the trigger button.

Claim 8, the drug delivery device according to claim 7, wherein

The push rod is driven by the vent button to move the sliding pusher distally during distal movement, the movement of the sliding pusher distally causing the trigger button to abut the sliding pusher distally.

The drug delivery device according to claim 9, wherein the drug delivery device further comprises:

A retaining element at least partially assembled within the vent button to move distally with the vent button and compress the injection spring during a first movement of the vent button.

The drug delivery device according to claim 10, 9, wherein the housing has a first housing stopper portion protruding inward,

The retaining element has a second resilient arm extending proximally;

After the first movement of the venting button, the second resilient arm moves from a proximal side of the first housing stop to a distal side of the first housing stop by deformation such that the first housing stop limits the movement of the retaining element proximally.

The drug delivery device according to claim 11, 9, wherein the push rod further comprises a proximal push rod end inserted into the venting button and a radial flange provided between the proximal push rod end and the distal push rod end, the injection spring being abutted between a proximal face of the radial flange and the holding element.

The drug delivery device according to claim 12, wherein the push rod is further formed with at least one push rod arm protruding radially distally of the radial flange, the sliding pusher having a pushing surface against which the push rod arm abuts.

The drug delivery device according to claim 13, wherein,

The force relief assembly includes a first force relief assembly configured to cause the pushrod to move proximally relative to the cartridge during a second movement of the venting button,

The first force relief assembly includes the push surface of the sliding ejector and the pusher arm, and the second movement of the air bleed button rotates the pusher and thereby slides the pusher arm over the push surface, the push surface being formed such that sliding the pusher arm over the push surface causes the pusher to move proximally relative to the cartridge.

The drug delivery device according to claim 14, wherein,

The pushing surface is formed into a slope inclined in the circumferential direction or a slope rising spirally.

Claim 15, the drug delivery device according to claim 13, wherein,

The second movement of the venting button includes rotation about a longitudinal axis in a direction of de-force rotation,

The proximal end of the push rod is in a form-fit with the venting button such that the push rod is movable in an axial direction relative to the venting button but is prevented from relative rotation, thereby driving the push rod to rotate together when the venting button is rotated.

The drug delivery device according to claim 16, wherein,

The second movement of the venting button further includes a proximal axial movement,

The holding member includes a holding member body provided with a fitting recess extending in a spiral shape on an outer peripheral surface thereof,

The venting button has a cylindrical wall with mating protrusions provided on an inside surface thereof,

The retaining element body fits within the cylindrical wall of the venting button such that the mating protrusion is received in the mating recess to allow the venting button to move axially relative to the retaining element while rotating relative to the retaining element.

The drug delivery device according to claim 17, wherein,

The housing has an inwardly protruding third housing stop portion,

The venting button has a third resilient arm extending circumferentially in a direction opposite the direction of force-dump rotation,

After the second movement of the venting button, the third resilient arm passes over the third housing stop in the circumferential direction such that the third housing stop prevents the venting button from rotating back.

The drug delivery device according to claim 18, wherein,

The venting button further includes a guide protrusion extending in an axial direction and a relief notch proximal to the guide protrusion;

The third housing stopper extends in the axial direction and protrudes inward, the housing further including: a fourth housing limit portion extending in the axial direction and protruding inward, and a fifth housing limit portion protruding inward and circumferentially spaced apart from the third and fourth housing limit portions in the force-releasing rotation direction;

the third housing limit portion extends distally beyond the fourth housing limit portion in the axial direction and is circumferentially opposite and spaced apart from the fourth housing limit portion in a direction opposite the direction of force-unloading rotation to define a thrust guide groove;

the guide projection of the venting button is axially slidably disposed in the advance guide groove, such that the venting button cannot be rotated,

After the first movement of the air release button, the avoidance notch of the air release button is aligned with the fourth housing limit part in the circumferential direction, and the guide protrusion of the air release button is aligned with the third housing limit part in the circumferential direction, so that the air release button can only rotate towards the unloading force rotation direction but not reversely rotate,

The fifth housing stopper is located in a force-releasing rotation direction of the guide protrusion to block the guide protrusion from further rotation in the force-releasing rotation direction after the second movement of the air release button.

The drug delivery device according to claim 19, according to any one of claims 1 to 18, wherein,

The force relief assembly includes a second force relief assembly configured to be actuated in response to the ram being moved distally by the injection assembly to completion of an injection, thereby moving the ram proximally relative to the cartridge.

The drug delivery device according to claim 20, according to any one of claims 9 to 18, wherein,

The force relief assembly includes a second force relief assembly configured to be actuated in response to the ram being moved distally by the injection assembly to completion of an injection, thereby moving the ram proximally relative to the cartridge,

The second force release assembly includes a force release ring sleeved on the sliding ejector, a force release spring for biasing the force release ring proximally, and a distally extending first resilient arm of the retaining element, wherein the first resilient arm is releasably abutted distally against the force release ring to block proximal movement of the force release ring.

Claim 21, the drug delivery device of claim 20, wherein distal movement of the push rod by the injection assembly releases the blocking of the force release ring by the first resilient arm, allowing the force release ring to move proximally under the force release spring, and whereby the force release ring pushes the push rod to move proximally.

The drug delivery device of claim 22, wherein the pushrod further forms a radially protruding pushrod arm distal to the radial flange,

During distal movement of the push rod by the injection assembly, the push rod arm laterally deflects the first resilient arm to release the stop for the drag ring.

The drug delivery device of claim 23, wherein the force relief ring comprises a proximally extending stop, the first resilient arm releasably abutting distally against the stop of the force relief ring.

The drug delivery device according to claim 24, wherein the stopper is formed in a stepped shape.

The drug delivery device according to claim 25, wherein,

The retention element moves the dump ring distally by the first resilient arm to compress the dump spring when moved distally during the first movement of the vent button.

The combination of one or more of the configurations of the elements in the drug delivery device in the above-described embodiments results in a compact and simple structure of the drug delivery device and enables the drug delivery device to reliably achieve accurate drug delivery operations including force-releasing operations.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present disclosure and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 shows a longitudinal cross-sectional view of a drug delivery device according to an embodiment of the present disclosure, wherein a needle replacement element is mounted on a cartridge;

fig. 2 shows another longitudinal cross-sectional reference view of the drug delivery device of fig. 1, wherein the needle replacement element is replaced with a needle;

fig. 3 shows an exploded perspective view of the drug delivery device of fig. 1;

FIG. 4 shows a perspective view of the push rod of the drug delivery device shown in FIG. 1;

fig. 5A and 5B are perspective views showing a venting button of the drug delivery device shown in fig. 1, respectively;

Fig. 6 shows a perspective view of a retaining element of the drug delivery device shown in fig. 1;

FIG. 7 shows a perspective view of a venting button and a retaining element fitted to the venting button of the drug delivery device shown in FIG. 1;

FIG. 8 shows a perspective view of a sliding ejector of the drug delivery device shown in FIG. 1;

FIG. 9 shows a perspective view of the force-release ring of the drug delivery device shown in FIG. 1;

Fig. 10 shows a perspective view of the sliding ejector of the drug delivery device shown in fig. 1 and a force-releasing ring fitted to the sliding ejector 9;

FIG. 11 shows a perspective view of a trigger button of the drug delivery device shown in FIG. 1;

Fig. 12A and 12B show perspective views of a first half-shell and a second half-shell, respectively, of the drug delivery device shown in fig. 1;

13-16B illustrate additional longitudinal cross-sectional reference views of the drug delivery device shown in FIG. 1, with the push rod of the drug delivery device of FIG. 13 in the vented position, the push rod of the drug delivery device of FIG. 14 in the first force-releasing position, the push rods of the drug delivery devices of FIGS. 15A and 15B in the drug delivery position, and the push rod of the drug delivery device of FIGS. 16A and 16B in the second force-releasing position, respectively;

FIG. 17 shows a perspective view of the drug delivery device shown in FIG. 1 with the pushrod in the venting position;

FIG. 18 shows a partial enlarged view of FIG. 17;

FIG. 19 shows a longitudinal cross-sectional reference view of the drug delivery device shown in FIG. 1 with the push rod in a first force-releasing position;

FIG. 20 shows a partial enlarged view of FIG. 19;

FIG. 21 shows a cross-sectional reference view of the drug delivery device shown in FIG. 1 taken at the guide projection of the venting button prior to pressing the venting button;

FIG. 22 shows a cross-sectional reference view of the drug delivery device shown in FIG. 1 taken at the guide projection of the venting button after depression of the venting button and prior to rotation of the venting button; and

Fig. 23 shows a cross-sectional reference view of the drug delivery device shown in fig. 1 taken at the guide protrusion of the venting button after rotation of the venting button.

Detailed Description

A drug delivery device according to an embodiment of the present disclosure is described in detail below with reference to the accompanying drawings. For the purposes of making the objects, technical solutions and advantages of the present disclosure more apparent, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure, and it is apparent that the described embodiments are some embodiments of the present disclosure, but not all embodiments.

Accordingly, the following detailed description of the embodiments of the present disclosure, provided in connection with the accompanying drawings, is not intended to limit the scope of the disclosure, as claimed, but is merely representative of selected embodiments of the disclosure. All other embodiments, which can be made by one of ordinary skill in the art without inventive effort, based on the embodiments in this disclosure are intended to be within the scope of this disclosure.

The singular forms include the plural unless the context defines otherwise. Throughout the specification the terms "comprises," "comprising," "includes," "including," and the like are used herein to specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

In addition, even though terms including ordinal numbers such as "first", "second", etc. may be used to describe various components, the components are not limited by these terms, and these terms are used only to distinguish one element from other elements. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the present disclosure.

In the description of the present disclosure, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc., are based on the directions or positional relationships shown in the drawings, or the directions or positional relationships conventionally put in place when the disclosed product is used, or the directions or positional relationships conventionally understood by those skilled in the art, are merely for convenience of description of the present disclosure and for simplification of description, and do not indicate or imply that the apparatus or elements referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present disclosure. As used herein and in the claims, the directional terms "proximal" or "proximal" refer to a direction proximal to a medical practitioner or the like manipulating the drug delivery device or a direction distal to a drug expelling needle of the drug delivery device and an end in that direction, while "distal" or "distal" refers to a direction opposite to "proximal" and pointing in the direction in which the drug is administered, or an end indicated by the distal direction.

Fig. 1 shows a longitudinal cross-section of a drug delivery device according to an embodiment of the present disclosure, wherein a needle replacement element 13 is mounted on a cartridge 1; fig. 2 shows a longitudinal cross-sectional reference view of the drug delivery device of fig. 1, wherein the needle replacement element 13 is replaced with a needle 14; fig. 3 shows an exploded perspective view of the drug delivery device of fig. 1, without showing the needle replacement element 13 or the needle 14.

As shown in fig. 1-3, the drug delivery device basically comprises a housing, a cap 5, a cartridge 1, a push rod 4, a venting button 7, an injection spring 11, a trigger button 8, a sliding ejector 9, a holding element 6, a force release ring 10 and a force release spring 12. Furthermore, the drug delivery device comprises a needle replacement element 13 or a needle 14, which are replaced with each other, both of which can be mounted to the distal end of the cartridge 1, e.g. by a threaded connection. Wherein the cartridge 1 is arranged distally of the housing and may be in communication with a needle 14 mounted for expelling the medicament in the cartridge 1 by pushing of the push rod 4. A venting button 7 is provided on the proximal side of the housing for venting air from the cartridge prior to drug injection, ensuring the accuracy of the injected dose. In addition, the venting process simultaneously compresses injection spring 11, accumulating energy for subsequent drug injections, and after trigger button 8 is actuated, injection spring 11 pushes plunger 4 distally, expelling drug through needle 14 to the target site of the patient. In order to further increase the accuracy of the injected dose, a de-pressurizing assembly after venting and/or a de-pressurizing assembly after injection, respectively, is provided in order to retract the push rod 4 proximally in time, preventing more than the intended dose of medicament from being expelled from the cartridge, which is particularly important for e.g. injecting a medicament with a higher viscosity.

The housing is cylindrical, but the specific shape of the housing is not limited. The housing is provided with a space for mounting the cartridge 1, in which space the cartridge 1 is mounted, the cartridge 1 having a longitudinal axis and a hollow accommodation space 101 for loading a medicament. In this embodiment, the drug delivery device is a preloaded drug delivery device. That is, the hollow accommodation space 101 of the cartridge 1 is preloaded with a drug to be administered. The user can expel air from the hollow housing space 101 by operating the drug delivery device, prick the needle 14 into the target site, and expel the drug from the hollow housing space 101 quantitatively for injection into the target site. The target site may include, for example, the posterior end of the eye, subconjunctival, periocular, anterior chamber, intravitreal, choroidal space, sclera, subcutaneous, intramuscular, intradermal, or the like.

The housing comprises a first housing half 2 and a second housing half 3 joined together in the longitudinal direction, having a housing proximal opening at the proximal end, a housing distal opening at the distal end and a housing lateral opening at the peripheral wall of the housing connecting the proximal and distal ends of the housing. The cartridge 1, the push rod 4, the injection spring 11, the sliding injector 9, the holding element 6, the force-release ring 10 and the force-release spring 12 are all completely accommodated in a housing, in which the venting button 7 and the trigger button 8 are partly accommodated and partly exposed outside the housing. The venting button 7 extends proximally to the outside of the housing via the proximal opening of the housing for operation by a user. The trigger button 8 is provided at a lateral opening of the outer peripheral wall of the housing and protrudes out of the outer peripheral wall for operation by a user. The distal portion of the cartridge 1 can be exposed via a housing distal opening, via which a needle displacing element 13 or a needle 14 can be mounted to the cartridge 1. A cap 5 covers the distal end of the housing to close the housing distal opening. In the present example, the first half-shell 2 and the second half-shell 3 are joined together along a plane including the longitudinal axis, but the present disclosure is not limited to the manner and position of joining of the first half-shell 2 and the second half-shell 3.

Fig. 4 shows a perspective view of the push rod 4 of the drug delivery device shown in fig. 1. As shown in fig. 4, the pushrod 4 is in the form of an elongated rod comprising a proximal pushrod end, a distal pushrod end and a rod body extending between the proximal and distal pushrod ends, with a radial flange 405 disposed on the rod body between the proximal and distal pushrod ends. Thus, the push rod 4 is composed of a first push rod section 401 near the proximal end of the push rod, a third push rod section 403 near the distal end of the push rod, and a second push rod section 402 between the first push rod section 401 and the third push rod section 403. A radial flange 405 is provided between the second pushrod section 402 and the third pushrod section 403. Furthermore, the push rod 4 comprises a radially protruding push rod arm 404 on the third push rod section 403 distally of the radial flange 405. The pusher arms 404 are, for example, two, which extend oppositely in the radial direction, but the application is not limited thereto.

Fig. 5A and 5B show perspective views of the venting button 7 of the drug delivery device shown in fig. 1, respectively. As shown in fig. 5A and 5B, the venting button 7 includes a cylindrical first cylindrical wall 702, a cylindrical second cylindrical wall 701 disposed within the first cylindrical wall 702, and a button proximal wall 709 (see fig. 1). Further, the venting button 7 further includes a fitting protrusion 706 provided on the inner side of the first cylindrical wall 702, a third elastic arm 703 connected to the first cylindrical wall 702 and extending in the circumferential direction, a guide protrusion 704 provided on the outer surface of the first cylindrical wall 702 and extending in the axial direction, and a relief notch 705 provided on the proximal side of the guide protrusion 704.

Fig. 6 shows a perspective view of the holding element 6 of the drug delivery device shown in fig. 1. As shown in fig. 6, the holding member 6 includes a holding member body 602, two diametrically opposed first elastic arms 601, and two diametrically opposed second elastic arms 603. The holding element body 602 comprises a housing mating section 6021, a push-fit section 6022 extending proximally from the housing mating section 6021, and a first accommodation space 6025 through the holding element body 602 in which the injection spring 11 is accommodated. The first resilient arm 601 extends distally from the holding element body 602 in the axial direction, and the second resilient arm 603 is connected to the housing mating section 6021 of the holding element body 602, extends proximally and is deflected laterally outwardly from the holding element body 602 in a free state. Fig. 7 shows a perspective view of the venting button 7 of the drug delivery device shown in fig. 1 and the holding element 6 fitted to the venting button 7. As shown in fig. 7, the push-fit section 6022 of the holding member 6 is inserted into the air release button 7 to be fitted to the air release button 7.

Fig. 8 shows a perspective view of the sliding ejector 9 of the drug delivery device shown in fig. 1. As shown in fig. 8, the sliding injector 9 includes a first injector body portion 901 and a second injector body portion 902 extending proximally from the first injector body portion 901. The second ejector main body portion 902 includes a second accommodation space 9023 in which the force-releasing spring 12 is accommodated, and a cylindrical support body 9024 extending distally from the proximal end face of the sliding ejector 9 into the second accommodation space 9023.

Fig. 9 shows a perspective view of the force-relief ring 10 of the drug delivery device shown in fig. 1. Fig. 10 shows a perspective view of the sliding ejector 9 of the drug delivery device shown in fig. 1 and the force release ring 10 fitted to the sliding ejector 9. As shown in fig. 8, 9 and 10, the power take-off ring 10 includes an annular power take-off ring body 1002 and a stepped stop 1001 extending proximally from the power take-off ring body 1002. The stripper ring body 1002 of the stripper ring 10 is slipped over the cylindrical support 9024 and the stop 1001 extends from the proximal end of the support 9024. The force-release ring 10 is configured to be axially slidable but not rotatable relative to the sliding thrust piece 9. For example, the outer flat surface 1003 of the force-relief ring body 1002 mates with an inner flat surface 9025 provided on the inner sidewall of the second thrust body portion 902 of the sliding thrust piece 9 such that the force-relief ring 10 is axially slidable but non-rotatable relative to the sliding thrust piece 9.

Fig. 11 shows a perspective view of the trigger button 8 of the drug delivery device shown in fig. 1. As shown in fig. 11, the trigger button 8 includes trigger restricting portions 801 and two fourth elastic arms 802 extending to both sides, respectively, at both ends, and a pivot shaft 803 between both ends.

Fig. 12A and 12B show perspective views of the first half-shell 2 and the second half-shell 3 of the drug delivery device shown in fig. 1, respectively. The first half-shell 2 and the second half-shell 3 are joined to each other, for example by means of a snap-fit, adhesive bonding or fastening, etc. The first and second half-shells 2, 3 have shaft receiving holes 208, 308, respectively, at the lateral openings of the shells for receiving a pivot shaft 803 of the trigger button 8 to pivotally mount the trigger button 8 to the shells. The first half-shell 2 and the second half-shell 3 also each comprise first and second limit guides 206, 306, 207, 307 protruding inwards. The first limit guides 206, 306 cooperate with a first form-fitting portion 604 (see fig. 6) provided on the holding element 6 to guide the axial sliding of the holding element 6 within the housing. The second limit guides 207, 307 cooperate with a second shape-fitting portion 904 (see fig. 8) provided on the slide pusher 9 to guide the axial sliding of the slide pusher 9 within the housing. For example, the first and second limit guides 206, 306, 207, 307 may extend generally in an axial direction.

Returning to fig. 1 and 2, a venting button 7 is mounted to the proximal end of the push rod 4. At least a portion of the first pushrod section 401 of the pushrod 4 is inserted into the second cylindrical wall 701 of the venting button 7. The push-fit section 6022 of the holding element 6 is inserted into the space formed between the first and second cylindrical walls 702, 701 of the venting button 7 such that the second cylindrical wall 701 passes through an intermediate opening formed in the proximal wall of the push-fit section 6022 into the first accommodation space 6025 of the holding element 6. The second pushrod section 402 of the pushrod 4 extends through the first accommodation space 6025. The injection spring 11 is mounted on the push rod 4, which is arranged at least partially around the second push rod section 402. The distal end of the injection spring 11 abuts the radial flange 405 of the push rod 4, and the proximal end of the injection spring 11 abuts distally against the distal face of the proximal wall 6024 of the holding element 6. The pusher arm 404 of the pusher 4 abuts distally against the proximal face of the sliding pusher 9 (see fig. 17), which serves as a pushing face 9021. The force release ring 10 and the force release spring 12 are accommodated in the second accommodation space 9023 of the sliding ejector 9. The force-releasing ring body 1002 of the force-releasing ring 10 is fitted over the cylindrical support 9024 of the sliding ejector 9 (see fig. 9 and 10). The dump spring 12 at least partially surrounds the cylindrical support 9024 with its distal end abutting the second housing stop 202, 302 of the housing and its proximal end abutting the dump ring body 1002 of the dump ring 10. The first ejection body portion 901 of the sliding ejector 9 is arranged around the cartridge 1 with a lateral opening 903, into which lateral opening 903 the trigger limiting portion 801 of the trigger button 8 can be inserted to releasably limit the distal axial movement of the sliding ejector 9. The third push rod section 403 of the push rod 4 is inserted through the sliding ejector 9 into the hollow accommodation space 101 of the cartridge 1 to define a drug accommodation space having a variable volume. The volume of the medicine containing space is changed by the axial movement of the push rod 4 to achieve the venting and the administration. The distal end of the push rod 4 is provided with a rubber stopper to seal the medicine containing space.

When using a drug, in particular a drug with a relatively high viscosity, the push rod 4 may cause wake problems when being pushed distally to expel air and/or the drug, i.e. more than the intended dose of drug is expelled from the cartridge 1 due to the inertia and viscosity of the drug, which results in that accurate dosing is not achieved. The drug delivery device of the embodiments of the present disclosure includes a first force-discharging assembly and a second force-discharging assembly, and allows for a post-venting and post-drug delivery force-discharging operation by the first force-discharging assembly and the second force-discharging assembly, respectively, i.e., the push rod 4 is moved distally a predetermined distance and then proximally a force-discharging distance less than the predetermined distance. The unloading operation can solve the wake problem, thereby achieving more accurate administration. Thus, the push rod 4 may be sequentially in the initial position, the discharge position moved distally from the initial position to discharge the air in the hollow accommodating space 101, the first force discharge position moved proximally from the discharge position to discharge the force, the administration position moved further distally from the first force discharge position to discharge the medicine in the hollow accommodating space 101, and the second force discharge position moved proximally from the administration position to discharge the force. When the push rod 4 is in the initial position, the air discharge position, the first force discharge position, the administration position, and the second force discharge position, the medicine containing space has an initial volume, an air discharge rear volume, a first force discharge volume, an air discharge rear volume, and a second force discharge volume, respectively, wherein the initial volume, the first force discharge volume, the air discharge rear volume, the second force discharge volume, and the air discharge rear volume are sequentially reduced.

The push rod 4 of the drug delivery device in fig. 1 and 2 is in the initial position. Fig. 13-16B show further longitudinal cross-sectional reference views of the drug delivery device shown in fig. 1, respectively, wherein the push rod 4 of the drug delivery device in fig. 13-16B is in a venting position (fig. 13), a first force-releasing position (fig. 14), a drug delivery position (fig. 15A and 15B), and a second force-releasing position (fig. 16A and 16B), respectively. Fig. 17 shows a partially cut-away perspective view of the drug delivery device shown in fig. 1, fig. 18 shows a partially enlarged view of fig. 17, fig. 19 shows a longitudinal cross-sectional reference view of the drug delivery device shown in fig. 1, fig. 20 shows a partially enlarged view of fig. 19, wherein the push rod 4 of the drug delivery device in fig. 17 and 18 is in a venting position and the push rod 4 of the drug delivery device in fig. 19 and 20 is in a first force-releasing position.

As shown in fig. 1,2 and 13, the venting button 7 is pressed to move axially distally when the venting operation is performed. Upon distal movement of the venting button 7, the second cylindrical wall 701 abuts a proximally facing stepped surface 4012 of the push rod 4 formed between the first push rod section 401 and the second push rod section 402 after a predetermined distance of movement to push the push rod 4 distally from the initial position to the venting position. Thus, the volume of the drug containing space of the cartridge 1 is reduced. At this point, the drug delivery device is positioned with the needle 14 facing upwards with respect to the direction of gravity to expel air from the drug containing space. Furthermore, when moved distally, the push rod 4 in turn pushes the sliding ejector 9 distally. When the push rod 4 is moved to the degassing position, the trigger button 8 abuts the sliding pusher 9 distally to releasably restrict further distal movement of the sliding pusher 9 and push rod 4. Specifically, the trigger restricting portion 801 of the trigger button 8 at the proximal end thereof is inserted into a lateral opening 903 provided in the side wall of the first ejection body portion 901 of the slide ejector 9, and the slide ejector 9 and the push rod 4 are releasably restricted from moving distally by abutting against the inner wall of the lateral opening 903 from the distal side. The fourth elastic arm 802 of the trigger button 8 abuts against the sliding ejector 9 to keep the trigger restricting portion 801 of the trigger button 8 inserted.

As the venting button 7 is moved towards the distal axis, the holding element 6 moves distally together with the venting button 7 and compresses the injection spring 11. Specifically, the venting button 7 further comprises a plurality of radial ribs 707 in the space between the first cylindrical wall 702 and the second cylindrical wall 701, located at the proximal end, extending radially from the first cylindrical wall 702 to the second cylindrical wall 701. As the venting button 7 moves toward the distal axis, the plurality of radial ribs 707 abut proximally against the proximal face of the proximal wall 6024 of the retaining element 6 to urge the retaining element 6 distally. Since the venting button 7 is moved distally together with the holding element 6 a predetermined distance before being moved distally against the push rod 4 to move the push rod 4 distally, the distance by which the push rod 4 is moved distally is smaller than the distance by which the holding element 6 is moved distally, which results in the injection spring 11 being compressed, thereby storing energy. When the holding element 6 moves distally, the second elastic arm 603 of the holding element 6 moves from the proximal side of the first housing stopper 201, 301 of the housing to the distal side of the first housing stopper 201, 301 by elastic deformation, so that the first housing stopper 201, 301 restricts the holding element 6 from moving proximally to maintain the position of the holding element 6 and to maintain the compression of the injection spring 11.

As shown in fig. 13 and 14, the venting button 7 is rotated clockwise when viewed proximally distally along the longitudinal axis to effect a post-venting force-dump operation, i.e. such that the push rod 4 is retracted again after being moved distally to vent to avoid the drug being undesirably expelled from the cartridge 1. The force is relieved using the first force relieving assembly. The first force-dump assembly is configured to cause the push rod 4 to move proximally during rotation of the vent button 7. In this embodiment, the first force-unloading assembly comprises a push surface 9021 of the sliding ejector 9. The push surface 9021 is more clearly shown in figures 10, 17 and 18. As shown in fig. 17 and 18, the proximal pushing surface 9021 of the sliding pusher 9 may have a slope inclined in the circumferential direction or a spiral rising slope. Of course, the pushing surface 9021 of the present invention is not limited to this shape, and may be, for example, an arc shape or other curved shape, as long as the pushing arm 404 can drive the pushing rod 4 to move axially proximally when the pushing arm 404 slides along the pushing surface 9021, and the specific shape thereof is not limited. In the exhaust position, the pusher arm 404 of the pusher 4 abuts the proximal pusher face 9021 of the sliding pusher 9. Rotation of the venting button 7 causes the pusher arm 404 to slide on the proximal pushing surface 9021, causing the pusher rod 4 to retract proximally from the venting position to the first force-releasing position. Fig. 19 and 20 show the proximal push surface 9021 and the pusher arm 404 of the pusher 4 in the first force-releasing position. In addition, the proximal push surface 9021 also has a distally concave retention recess 9022 (shown in fig. 10 and 20). When the venting button 7 is rotated clockwise, the pusher arm 404 slides over the proximal pusher face 9021 and into the holding recess 9022 to maintain its circumferential position.

The first pushrod section 401 of the pushrod 4 is inserted into the second cylindrical wall 701 of the venting button 7. The outer flat surface 4011 (shown in fig. 4) of the first push rod 4 mates with the inner flat surface 7011 (shown in fig. 5B) of the second cylindrical wall 701 such that the push rod 4 rotates with the exhaust button 7 and is axially movable relative to the exhaust button 7. As shown in fig. 6, the holding member body 602 of the holding member 6 is provided on its outer peripheral surface with a fitting recess 6023 extending in a spiral shape. As shown in fig. 5A and 5B, the first cylindrical wall 702 of the air release button 7 is provided on the inner side surface thereof with a fitting protrusion 706. The push-fit section 6022 of the retaining element 6 is inserted into the first cylindrical wall 702 such that the mating protrusion 706 is received in the mating recess 6023. Thus, when the venting button 7 is rotated, the engagement protrusion 706 moves along the helically extending engagement recess 6023, so that the venting button 7 moves proximally in the axial direction. The mating recess 6023 may have a lift angle greater than the lift angle of the proximal push surface 9021 such that the distance that the venting button 7 moves proximally axially is greater than the push rod 4 to avoid interference of the venting button 7 with proximal movement of the push rod 4.

As shown in fig. 14 to 15B, the trigger button 8 is operated to release the restriction of the slide ejector 9 by the trigger button 8, thereby activating the administration operation. Specifically, the trigger button 8 is released by pressing the distal end of the trigger button 8. When the distal end of the trigger button 8 is pressed, the fourth elastic arm 802 of the trigger button 8 is deformed to allow the trigger button 8 to pivot about the pivot shaft 803, so that the trigger restricting portion 801 of the trigger button 8 moves away from the slide ejector 9, releasing the blocking of the slide ejector 9. In this way, the sliding ejector 9 is moved distally and the push rod 4 is moved axially distally from the first force-releasing position to the administration position by the injection spring 11, the energy stored by the injection spring 11 being compressed upon venting being released. At this time, the needle 14 has been pricked into the target site, and the volume of the medicine containing space is reduced to discharge the medicine from the needle 14 to the target site.

After administration, the force is relieved using a second force relief assembly to avoid unwanted expulsion of excess drug from the cartridge 1. 15A-16B, after the push rod 4 is moved to the administration position, the second force relief assembly is actuated in response to the push rod 4 being moved distally a predetermined distance from the first force relief position to the administration position, thereby moving the push rod 4 proximally to effect a second force relief operation, i.e., retracting the push rod 4 proximally to the second force relief position after being moved distally to administer the drug. The second force-relieving assembly comprises a force-relieving ring 10 which is fitted over the sliding ejector 9, a force-relieving spring 12 for biasing the force-relieving ring 10 proximally, and a distally extending first resilient arm 601 of the holding element 6.

Referring back to fig. 2 and 13, during pressing of the venting button 7, the holding element 6 moves distally together with the venting button 7, and the holding element 6 in turn further pushes the force-relief ring 10 distally via its first resilient arm 601 to compress the force-relief spring 12 such that the force-relief spring 12 stores energy. The first resilient arm 601 is releasably abutted proximally against the stepped blocking portion 1001 of the unloading force ring 10 to block proximal movement of the unloading force ring 10.

As shown in fig. 15A-16B, the blocking of the drag ring 10 by the first resilient arm 601 is released when the push rod 4 is moved from the first drag release position to the drug delivery position. Thus, the stored energy of the dump spring 12 due to compression is released, pushing the push rod 4 via the dump ring 10 to move axially proximally to the second dump position. Specifically, as shown in fig. 19 and 20, after the air release button 7 rotates the push rod 4 about the longitudinal axis such that the push rod 4 moves axially to the first force release position, the push rod arm 404 is received in the holding recess 9022. When the push rod 4 is moved from the first force-releasing position to the dosing position, the push rod arm 404 moves the blocking end 6011 of the first resilient arm 601 laterally away from the blocking portion 1001 of the force-releasing ring 10 during distal movement, thereby releasing the blocking of the force-releasing ring 10. By appropriately setting the strength of the injection spring 11 and the unload spring 12, a predetermined dose of medicine can be administered.

As shown in fig. 20, the blocking end portion 6011 of the first elastic arm 601 has a distal end face 6012 facing distally and a first inclined face 6013, a second inclined face 6014, and a third inclined face 6015 inclined with respect to the axial direction in order in the axial direction from the distal side toward the proximal side. The first inclined surface 6013 and the second inclined surface 6014 define a blocking recess 6016 (see fig. 6) recessed in the lateral direction, and the second inclined surface 6014 and the third inclined surface 6015 define a blocking projection 6017 (see fig. 6) protruding in the lateral direction. The inclination angle of the first inclined surface 6013 is smaller than that of the second inclined surface 6014. The blocking portion 1001 of the force-release ring 10 has a stepped end face with a first stepped projection 1003 and a second stepped projection 1004 in sequence from the distal side towards the proximal axial direction. The distal end face 6012 abuts the proximal end face of the first stepped projection 1003, the second stepped projection 1004 abuts within the blocking recess 6016, and the distal end face of the second stepped projection 1004 abuts the blocking projection 6017. When the trigger button 8 is triggered, the third inclined surface 6015 is provided on the moving path of the pusher arm 404 during movement of the pusher 4 to the administration position, and the pusher arm 404 pushes the first elastic arm 601 to be biased in the lateral direction perpendicular to the axial direction via the third inclined surface 6015. The shape of the blocking portion 1001 of such a force-relief ring 10 and the blocking end 6011 of the first resilient arm 601 allows the first resilient arm 601 to be reliably and smoothly deflected to move the push rod 4 to the second force-relief position.

Furthermore, the first resilient arm 601 comprises an anti-deflection portion 6018 for cooperating with the sliding ejector 9 to prevent accidental release of the blocking of the force-dump ring 10 by the first resilient arm 601 before the push rod 4 is moved to the dosing position. Specifically, referring to fig. 6 and 10, 20, an anti-offset portion 6018 is provided proximal to the blocking end portion 6011, protruding in the lateral direction in which the first elastic arm 601 is offset by the pusher arm 404. Before the push rod 4 is moved to the administration position, the misalignment preventing engagement portion 9026 of the slide ejector 9 is aligned with the misalignment preventing portion 6018 in the lateral direction to block the first elastic arm 601 from being misaligned. After the push rod 4 is moved to the administration position, the anti-misalignment mating portion 9026 of the sliding ejector 9 is moved axially away from the anti-misalignment portion 6018 to release the blocking of the first resilient arm 601.

Fig. 21 shows a cross-sectional reference view of the drug delivery device shown in fig. 1 taken at the guide protrusion 704 of the venting button 7 before the venting button 7 is pressed, fig. 22 shows a cross-sectional reference view of the drug delivery device shown in fig. 1 taken at the guide protrusion 704 of the venting button 7 before the venting button 7 is rotated after the venting button 7 is pressed, and fig. 23 shows a cross-sectional reference view of the drug delivery device shown in fig. 1 taken at the guide protrusion 704 of the venting button 7 after the venting button 7 is rotated. As shown in fig. 21, before the air release button 7 is pressed, the guide projection 704 of the air release button 7 is positioned in the push guide groove between the third housing limit part 203 of the first half housing 2 and the fourth housing limit part 304 of the second half housing 3 so that the air release button 7 can slide axially but cannot rotate. The third housing stopper 203 and the fourth housing stopper 304 extend in the axial direction and the lateral direction and protrude inward. A portion of the third housing stopper 203 is opposed to and spaced apart from the fourth housing stopper 304 in the circumferential direction (or lateral direction) to define a push guide groove, and the third housing stopper 203 extends distally beyond the fourth housing stopper 304 in the axial direction. As shown in fig. 22, after the purge button 7 is pressed, the escape notch 705 (see fig. 5A) of the purge button 7 is aligned with the fourth housing stopper 304 in the circumferential direction, and the guide projection 704 of the purge button 7 is aligned with the third housing stopper 203 in the circumferential direction, so that the purge button 7 can be rotated only in the force-releasing rotation direction for the first force-releasing operation and cannot be rotated reversely. The discharging force rotation direction is a rotation direction of the discharging button in the discharging force operation after the discharging. As shown in fig. 23, after the air release button 7 is rotated, the third elastic arm 703 extending circumferentially in the unloading rotation direction passes over the third housing stopper 203 in the circumferential direction, so that the third housing stopper 203 prevents the air release button 7 from rotating back. And, the guide protrusion 704 is rotated to be adjacent to the fifth housing stopper 305, and is blocked from continuing the rotation by the fifth housing stopper 305. The fifth housing stopper 305 is circumferentially spaced apart from the third and fourth housing stoppers 203 and 304 in the force-releasing rotation direction of the exhaust button 7, and protrudes inward. The cooperation of the venting button 7 with the respective limit portions in the housing allows reliable operation of the drug delivery device, avoiding mishandling.

The present disclosure is not limited to the above-described embodiments, and various modifications, variations, substitutions, or supplements may be made within the scope of the present disclosure. Further, the shape, size, number, and arrangement position of the constituent elements in the above-described embodiments are optional, and are not limited as long as the present disclosure can be realized.

For example, in the above-described embodiment, the push rod 4 is driven to move distally in the axial direction by the axial movement of the air release button 7, and then the push rod 4 is allowed to move proximally by the rotation of the air release button 7. In other embodiments, the push rod 4 may be driven to move distally in the axial direction by rotation of the venting button 7. For example, the rotation of the air release button 7 is converted into an axial movement by the cooperation of the air release button 7 with a spiral guide in the housing to bring about the movement of the push rod 4 in the axial direction. For example, the push rod 4 is rotated together with the venting button 7 and the rotation of the push rod 4 is converted into an axial movement by the cooperation of the push rod 4 with a helical guide in an element such as the housing or cartridge 1. Furthermore, in other embodiments, the push rod 4 may be driven to move distally in the axial direction by other means of movement of the venting button 7, or the push rod 4 may be allowed to move proximally.

For example, in the above-described embodiments, the drug delivery device includes both a first force-relief assembly and a second force-relief assembly. In other embodiments, the drug delivery device may include only one of the first force-relief assembly and the second force-relief assembly as desired. In this way, the drug delivery device can only achieve a corresponding one of the first unloading operation after venting and the second unloading operation after drug delivery. Moreover, in other embodiments, the first and second force-relief assemblies may have other configurations.

For example, in the above-described embodiment, the pushing surface 9021 of the sliding pusher 9 is located at the proximal end, and the pusher arm 404 of the pusher 4 for abutting against the pushing surface 9021 protrudes radially outward. In other embodiments, the push surface 9021 may be located elsewhere, or the push rod 4 may abut the push surface 9021 of the sliding pusher 9 via the distal end surface of the radial flange 405.

Although in the above described embodiments the cartridge 1 is mounted in the housing for sale or delivery to a user as a whole before the housing halves 2 and 3 are snapped together, the invention is not limited thereto, e.g. in other embodiments the housing 2 and 3 may be of a removable design at the part where the cartridge is mounted for re-placement of the cartridge 1 after the drug delivery device is fully assembled or for loading of an optional cartridge into the drug delivery device by a medical staff when the drug delivery device is sold to a user, e.g. a medical staff.

The scope of the present disclosure is defined not by the above-described embodiments but by the appended claims and their equivalents.

Claims

1. A drug delivery device comprising:

2. The drug delivery device of claim 1, wherein,

3. The drug delivery device of claim 2, wherein,

4. The drug delivery device of claim 2, wherein the first movement of the venting button is a distal axial movement.

5. The drug delivery device of claim 3, the second movement of the venting button being a rotation about a longitudinal axis and a proximal axial movement.

6. The drug delivery device of claim 2, wherein,

The injection assembly comprises:

7. The drug delivery device of claim 6, further comprising

8. The drug delivery device of claim 7, wherein

9. The drug delivery device of claim 7, further comprising:

10. The drug delivery device of claim 9, wherein the housing has an inwardly protruding first housing stop,

The retaining element has a second resilient arm extending proximally;