A sub-assembly of a medicament delivery device

The present disclosure provides a sub-assembly of a medicament delivery device, the sub-assembly comprising: a housing extending along a longitudinal axis between a proximal end and a distal end, a plunger rod arranged within the housing; wherein the plunger rod comprises a plunger rod body and a ledge extending from the plunger rod body in a direction transverse to the longitudinal axis; a biasing member configured to bias the plunger rod relative to the housing in the direction of the longitudinal axis; and a plunger rod holder axially immovable relative to the housing; wherein the ledge of the plunger rod defines two opposite surfaces facing towards the distal end and the proximal end of the housing respectively; and wherein one of the two opposite surfaces is configured to engage with the biasing member and the other one of the two opposite surfaces is configured to releasably engage with the plunger rod holder.

TECHNICAL FIELD

The present disclosure generally relates to a sub-assembly of a medicament delivery device, and particularly to a sub-assembly comprises a plunger rod comprising a plunger rod body and a ledge extending from the plunger rod body.

BACKGROUND

Medicament delivery devices such as pen type manual injectors or auto-injectors are generally known for the self-administration of a medicament by patients without formal medical training. For example, patients suffering from diabetes may require repeated injections of insulin, or patients may require regular injections of other types of medicaments, such as a growth hormone.

It is an advantage when the medicament delivery devices for the self-administration comprise automatic functions, so that even if users are without professional training or are in an emergency situation, the users can easily and properly use the medicament delivery devices.

Even though many of the devices on the market, as well as the ones described above, have their respective advantages, there is still room for improvements.

SUMMARY

The invention is defined by the appended claims, to which reference should now be made.

In the present disclosure, when the term “distal direction” is used, this refers to the direction pointing away from the dose delivery site during use of the medicament delivery device. When the term “distal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which under use of the medicament delivery device is/are located furthest away from the dose delivery site. Correspondingly, when the term “proximal direction” is used, this refers to the direction pointing towards the dose delivery site during use of the medicament delivery device. When the term “proximal part/end” is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which under use of the medicament delivery device is/are located closest to the dose delivery site.

Further, the term “longitudinal”, “longitudinally”, “axially” or “axial” refer to a direction extending from the proximal end to the distal end, typically along the device or components thereof in the direction of the longest extension of the device and/or component.

Similarly, the terms “transverse”, “transversal” and “transversally” refer to a direction generally perpendicular to the longitudinal direction.

Further, the terms “circumference”, “circumferential”, or “circumferentially” refer to a circumference or a circumferential direction relative to an axis, typically a central axis extending in the direction of the longest extension of the device and/or component. Similarly, “radial” or “radially” refer to a direction extending radially relative to the axis, and “rotation”, “rotational” and “rotationally” refer to rotation relative to the axis.

There is hence provided a sub-assembly of a medicament delivery device, the sub-assembly comprising: a housing extending along a longitudinal axis between a proximal end and a distal end, a plunger rod arranged within the housing; the plunger rod comprises a plunger rod body and a ledge extending from the plunger rod body in a direction transverse to the longitudinal axis; a biasing member configured to bias the plunger rod relative to the housing in the direction of the longitudinal axis; and a plunger rod holder axially immovable relative to the housing. The ledge of the plunger rod defines two opposite surfaces facing towards the distal end and the proximal end of the housing respectively. One of the two opposite surfaces is configured to engage with the biasing member and the other one of the two opposite surfaces is configured to releasably engage with the plunger rod holder.

Preferably, according to another embodiment, the housing comprises a proximally directed surface; the ledge defines a distally directed surface and a proximally directed surface; the biasing member extends along the longitudinal axis between a proximal end and a distal end; the proximal end of the biasing member is adjacent to the distally directed surface of the ledge of the plunger rod, and the distal end of the biasing member is adjacent to the proximally directed surface of the housing.

Preferably, according to another embodiment, the biasing member is a compression spring surrounding at least a part of the plunger rod body.

Preferably, according to another embodiment, the plunger rod holder comprises a distally directed surface; and the plunger rod holder is movable relative to the plunger rod between a first position where the distally directed surface aligns with and faces towards the proximally directed surface of the ledge of the plunger rod and a second position where the distally directed surface is transverse offset to the proximally directed surface of the ledge of the plunger rod.

Preferably, according to another embodiment, the plunger rod holder comprises a flexible arm that can flex from the first position to the second position; the flexible arm extends from a wall of the housing, and the distally directed surface of the plunger rod holder is on a protrusion extending from the flexible arm in the direction transverse to the longitudinal axis.

Alternatively, according to another embodiment, the plunger rod holder is rotatable around the longitudinal axis relative to the housing from the first position to the second position; the plunger rod holder comprises a protrusion extending towards the plunger rod body; and the distally directed surface of the plunger rod holder is on the protrusion.

Preferably, the plunger rod holder comprises a cylindrical or semi-cylindrical holder body; and the protrusion of the plunger rod holder extends from a wall of the holder body.

Preferably, according to another embodiment, the sub-assembly comprises an actuator comprising an actuator surface; the plunger rod holder comprises an actuated surface facing towards the actuator surface; wherein at least one of the actuator surface and the actuated surface is bevelled relative to the longitudinal axis; and the actuator surface is configured to move along the actuated surface with a movement of the actuator relative to the plunger rod holder in the direction of the longitudinal axis, thereby moving the plunger rod holder from the first position to the second position.

Preferably, according to another embodiment, the actuator surface is a distally directed surface; the actuated surface is a proximally directed surface and wherein the actuator surface is configured to move along the actuated surface with a movement of the actuator relative to the plunger rod holder towards the distal end of the housing, thereby moving the plunger rod holder from the first position to the second position.

Preferably, according to another embodiment, the actuated surface is bevelled between a proximal end to a distal end; and the actuator is axially movable relative to the plunger rod holder from a proximal position where the actuator surface is adjacent to the proximal end of the actuated surface to a distal position where the actuator surface is adjacent to the distal end of the actuated surface.

Preferably, according to another embodiment, the sub-assembly comprises a delivery member cover axially movable relative to the housing; the delivery member cover comprises a tubular section configured to surround a medicament delivery member of the medicament delivery device; the delivery member cover comprises an arm extending from the tubular section towards the distal end of the housing, and the actuator extends from the arm of the delivery cover towards the longitudinal axis.

Preferably, according to another embodiment, the sub-assembly comprises an outer shell extending along the longitudinal axis between a proximal end and a distal end; the outer shell is configured to receive a medicament container of the medicament delivery device; the housing is axially immovable arranged within the outer shell.

Preferably, according to another embodiment, the plunger rod comprises an engaging member; the engaging member is closer to the distal end of the outer shell than the ledge of the plunger rod; the housing comprises a counter engaging member engaged with the engaging member of the plunger rod; one of the engaging member and the counter engaging member is arranged on a flexible arm; the sub-assembly comprises safety member removably attached to the distal end of the outer shell; a cut-out arranged at the distal end of the outer shell; and the safety member comprises a support wall protruding into the outer shell through the cut-out of the outer shell and configured to block the flexible arm from flexing.

Preferably, according to another embodiment, the housing comprises a distal opening; the counter engaging member of the housing is a distally directed surface extending from the distal end of the housing into the distal opening; the plunger rod comprises a flexible arm protruding from the distal opening of the housing; the engaging member of the plunger rod is a proximally directed surface on the flexible arm; the proximally directed surface adjacent to the distally directed surface of the housing; and the flexible arm is arranged between the support wall of the safety member and an edge of the distal opening of the housing in the direction transverse to the longitudinal axis.

Alternatively, according to another embodiment, the engaging member of the plunger rod is a recess or cut-out is arranged in a sidewall of the plunger rod body; the housing comprises a flexible arm extending from a distally directed wall of the housing towards a proximally directed wall of the outer shell; the counter engaging member of the housing is a protrusion extending from the flexible arm; the protrusion of the flexible arm protrudes into the recess or cut-out of the plunger rod body, and the support wall of the safety member encloses an outer surface of the flexible arm of the housing.

Preferably, according to another embodiment, the cut-out of the outer shell is arranged in the proximally directed wall of the outer shell.

Preferably, according to another embodiment, the tubular section of the delivery member cover is telescopic relative to the proximal end of the outer shell.

Preferably, according to another embodiment, the sub-assembly is used in a medicament delivery device comprising a multiple-chamber medicament container arranged within the carrier.

Preferably, according to another embodiment, the medicament delivery device is an injection device, an inhalation device, or a medical sprayer.

Preferably, according to another embodiment, the medicament delivery device is an auto-injector.

Preferably, according to another embodiment, the medicament delivery member is an injection needle or a spray nozzle.

Preferably, according to another embodiment, the medicament container is syringe or a cartridge.

Generally, the medicament delivery devices described herein can be used for the treatment and/or prophylaxis of one or more of many different types of disorders. Exemplary disorders include, but are not limited to: rheumatoid arthritis, inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis), hypercholesterolaemia, diabetes (e.g. type 2 diabetes), psoriasis, migraines, multiple sclerosis, anaemia, lupus, atopic dermatitis, asthma, nasal polyps, acute hypoglycaemia, obesity, anaphylaxis and allergies. Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to (with non-limiting examples of relevant disorders in brackets): etanercept (rheumatoid arthritis, inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis)), evolocumab (hypercholesterolaemia), exenatide (type 2 diabetes), secukinumab (psoriasis), erenumab (migraines), alirocumab (rheumatoid arthritis), methotrexate (amethopterin) (rheumatoid arthritis), tocilizumab (rheumatoid arthritis), interferon beta-1a (multiple sclerosis), sumatriptan (migraines), adalimumab (rheumatoid arthritis), darbepoetin alfa (anaemia), belimumab (lupus), peginterferon beta-1a′ (multiple sclerosis), sarilumab (rheumatoid arthritis), semaglutide (type 2 diabetes, obesity), dupilumab (atopic dermatis, asthma, nasal polyps, allergies), glucagon (acute hypoglycaemia), epinephrine (anaphylaxis), insulin (diabetes), atropine and vedolizumab (inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis)). Pharmaceutical formulations including, but not limited to, any drug described herein are also contemplated for use in the medicament delivery devices described herein, for example pharmaceutical formulations comprising a drug as listed herein (or a pharmaceutically acceptable salt of the medicament) and a pharmaceutically acceptable carrier. Pharmaceutical formulations comprising a drug as listed herein (or a pharmaceutically acceptable salt of the medicament) may include one or more other active ingredients, or may be the only active ingredient present.

Furthermore, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.

DETAILED DESCRIPTION

FIGS.1-13illustrate a sub-assembly of a medicament delivery device, the sub-assembly comprising: a housing3extending along a longitudinal axis L between a proximal end and a distal end, a plunger rod5arranged within the housing3, a biasing member6configured to bias the plunger rod5relative to the housing3in the direction of the longitudinal axis L, and a plunger rod holder32axially immovable relative to the housing3. As shown inFIG.4A, the housing3comprises a tubular body30configured to receive the plunger rod5and the biasing member6.

As shown inFIG.3, the plunger rod5comprises a plunger rod body50and a ledge51extending from the plunger rod body50in a direction transverse to the longitudinal axis L. The plunger rod body50extends in the direction of the longitudinal axis L. In this example, the ledge51of the plunger rod5is an annular ledge51. Alternatively, the ledge is an arm or semi-circular ledge extending partially around the plunger rod body. The ledge51defines two opposite surfaces51a,51bfacing towards the distal end and the proximal end of the housing3respectively. One of the two opposite surfaces is configured to engage with the biasing member6and the other one of the two opposite surfaces is configured to releasably engage with the plunger rod holder32. The two opposite surfaces are a distally directed surface51aand a proximally directed surface51b.In the example, shown inFIG.3, the distally directed surface51ais configured to engage with the biasing member and the proximally directed surface51bis configured to releasably engage with the plunger rod holder32. In this example, the biasing member6extends along the longitudinal axis L between a proximal end and a distal end. The proximal end of the biasing member6is adjacent to the distally directed surface51aof the ledge51of the plunger rod5and the distal end of the biasing member3is adjacent to a proximally directed surface30aof the housing3, as shown inFIG.13. In a preferred example, the biasing member3is a compression spring3surrounding at least a part of the plunger rod body50, as shown inFIG.13.

The plunger rod holder32comprises a distally directed surface32bconfigured to releasably engage with the proximally directed surface51bof the ledge51of the plunger rod5. The plunger rod holder32is movable relative to the plunger rod5between a first position where the distally directed surface32baligns with and faces towards the proximally directed surface51bof the ledge51of the plunger rod5and a second position where the distally directed surface32bis transverse offset to the proximally directed surface51bof the ledge51of the plunger rod5. Therefore, when the plunger rod holder32is in the second position, the plunger rod5is no longer blocked by the distally directed surface32bof the plunger rod holder32from moving towards the proximal end of the housing, so that the plunger rod5can be moved in the direction of the longitudinal axis relative to the housing3under by the biasing member6.

In the example, shown inFIGS.4A-4B, the plunger rod holder32comprises a flexible arm320that can flex from the first position to the second position. The flexible arm320extends from a wall of the housing3. Preferably, the flexible arm extends from a wall of the tubular body30of the housing3. The distally directed surface32bof the plunger rod holder32is on a protrusion32aextending from the flexible arm320in the direction transverse to the longitudinal axis L. In this example, when the plunger rod holder32is in the second position, the distally directed surface32bis radially offset to the proximally directed surface51bof the ledge51of the plunger rod5. Optionally, the plunger rod holder32comprises a support surface32dfacing towards the longitudinal axis L. The support surface32dis configured to support the ledge51of the plunger rod5from a side of the ledge51.

Alternatively, the plunger rod holder is rotatable around the longitudinal axis relative to the housing from the first position to the second position. In this example, the plunger rod holder comprises a protrusion extending towards the plunger rod body. The distally directed surface of the plunger rod holder is on the protrusion. In this example, when the plunger rod holder is in the second position, the distally directed surface is circumferentially offset from the proximally directed surface of the ledge of the plunger rod. In this example, the plunger rod holder comprises a cylindrical or semi-cylindrical holder body. The protrusion of the plunger rod holder extends from a wall of the holder body.

In the example shown inFIG.2andFIG.5, the sub-assembly comprises an actuator42comprising an actuator surface42a.The plunger rod holder32comprises an actuated surface32cfacing towards the actuator surface42a,as shown inFIG.8. The actuator42is configured to move in the direction of the longitudinal axis relative to the housing3to move the plunger rod holder32from the first position to the second position. At least one of the actuator surface and the actuated surface is bevelled relative to the longitudinal axis L, so that when the actuator surface of the actuator axially moves along the actuated surface of the plunger rod holder, the plunger rod holder is moved from the first position to the second position. In a preferred example, both actuator surface42aand the actuated surface32care bevelled relative to the longitudinal axis L, as shown inFIG.8.

In a preferred example, the actuator surface42ais a distally directed surface and the actuated surface32cis a proximally directed surface, as shown inFIG.8. In this example, the actuator surface42ais configured to move along the actuated surface32cwith a movement of the actuator42relative to the plunger rod holder32towards the distal end of the housing3, thereby moving the plunger rod holder32from the first position to the second position. In this example, the sub-assembly comprises a delivery member cover4axially movable relative to the housing3, as shown inFIG.2andFIG.5. The delivery member cover4comprises a tubular section40configured to surround a medicament delivery member of the medicament delivery device. The delivery member cover4comprises an arm41extending from the tubular section towards the distal end of the housing3. The actuator42extends from the arm41of the delivery cover4towards the longitudinal axis L, as shown inFIG.5. In a preferred example, the actuated surface32cis bevelled between a proximal end to a distal end. The actuator42is axially movable relative to the plunger rod holder32from a proximal position where the actuator surface42ais adjacent to the proximal end of the actuated surface32cto a distal position where the actuator surface42ais adjacent to the distal end of the actuated surface32c.

In one example where the plunger rod holder32comprises the flexible arm320, the actuated surface32cis on the protrusion32a,as shown inFIG.4B. In this example, when the actuator42axially moves in the direction of the longitudinal axis L relative to the plunger rod holder32, the actuator surface42amoves in contact with the actuated surface32c,then moves along the actuated surface32c,thereby moving the flexible arm320flexes radially relative to the plunger rod in the direction transverse to the longitudinal axis. In the example shown inFIG.9, the flexible arm320flexes radially outward relative to the plunger rod (shown as the X direction inFIG.9). The distally directed surface32bof the plunger rod holder32thereby is radially offset to the proximally directed surface51bof the ledge51of the plunger rod5. It should be noted that the flexible arm can also be configured to flex radially inward relative to the plunger rod to move into the second position, dependent on the bevelling direction of the actuated surface. This example is preferred when the ledge of the plunger rod is an arm instead of an annular ledge.

Alternatively, in one example where the plunger rod holder is rotatable around the longitudinal axis L relative to the housing, the actuated surface is arranged on the holder body, so that the axial movement of the actuator causes the actuator surface to move along the actuated surface and thereby rotating the plunger rod holder from the first position to the second position. In this example, the distally directed surface of the plunger rod holder thereby is circumferentially offset to the proximally directed surface of the ledge of the plunger rod.

In a preferred example, the housing3comprises a slot33in the wall of the tubular body30. The slot33extends from a proximal end of the tubular body to the plunger rod holder32. The actuator42is configured to move along the slot33, as shown inFIG.6, towards the plunger rod holder32.

In a preferred example, the sub-assembly comprises a delivery member cover biasing member7configured to move the delivery member cover in the proximal direction relative to the housing3. The sub-assembly optionally comprises a container carrier8configured to receive a medicament container M, e.g. a syringe or a cartridge. In a preferred example, the container carrier8is axially fixed to the housing3, e.g. by a snap-fit engagement with a fastener31of the housing3. In this example, the delivery member cover biasing member7is positioned between the container carrier8and the tubular section40of the delivery member cover4. For example, the delivery member cover biasing member7is a compression spring7adjacent to a distally directed surface of the container carrier8at a distal end of the compression spring, and adjacent to a proximally directed surface of the tubular section40of the delivery member cover4. Therefore, the tubular section40of the delivery member cover4is moved to a position where the tubular section covers the medicament delivery member by the delivery member cover biasing member7. When a user wants to carry out a medicament delivery operation, the user will move the delivery member cover4in the distal direction relative to the housing3, so that the medicament delivery member can be exposed. This distal movement of the delivery member cover4causes the actuator42to axially move relative to the plunger rod holder32from the proximal position to the distal position, and thereby the plunger rod holder32is moved by the actuator42from the first position to the second position, as mentioned above.

It should be noted that the actuator can also be attached to a button at the distal end of the housing or position on a sidewall of the tubular body of the housing. If the button is configured to be moved from a distal position to a proximal position for triggering a medicament delivery operation, instead of the example mentioned above, in this example, the actuator surface42ais a proximally directed surface and the actuated surface32cis a distally directed surface.

In another example, the plunger rod5is axially movable relative to the housing3′ from a distal position where the proximally directed surface51bof the ledge51of the plunger rod5is spaced apart from the distally directed surface32bof the plunger rod holder32to a proximal position where the proximally directed surface51bof the ledge51of the plunger rod5is adjacent to the distally directed surface32bof the plunger rod holder32. In this example, the plunger rod5comprises an engaging member52. In a preferred example, the engaging member52is closer to the distal end of the plunger rod5than the ledge51, as shown inFIG.3. The housing3′ comprises a counter engaging member34engaged with the engaging member52of the plunger rod5, as shown inFIG.13. One of the engaging member and the counter engaging member is arranged on a flexible arm; in a preferred example, the counter engaging member34comprises an arm extending from the distal end of the housing3′ in the distal direction of the housing3′. In a preferred example, the counter engaging member34is a distally directed surface extending from the distal end of the housing3′. In this example, the counter engaging member is a protrusion extending from the arm in the direction transverse to the longitudinal axis L and thereby defining the distally directed surface. In this example, the engaging member52of the plunger rod is formed by a recess or a cut-out52in the plunger rod body50. When the engaging member34and the counter engaging member are engaged together, the protrusion of the counter engaging member34is positioned within the recess or cut-out52of the plunger rod5, as shown inFIG.11andFIG.13. The sub-assembly comprises a removable support wall91enclosing the arm of the counter engaging member34of the housing3′. For example, the removable support wall91can be formed by a ring or a tubular component that is removably attached to the housing3′. Therefore, when the support wall encloses the arm of the counter engaging member34of the housing3′, the plunger rod5is held in the distal position by the engagement between the engaging member52and the counter engaging member34, as shown inFIG.13. The interface formed between the engaging member52and the counter engaging member34is bevelled, so that when the support wall91is removed from the housing3′, the biasing member6moves the plunger rod5to deflect the arm of the counter engaging member34, thereby disengaging the engaging member52of the plunger rod5from the counter engaging member34of the housing3′ and moving the plunger rod5to the proximal position.

Alternatively, the housing comprises a distal opening, and the counter engaging member of the housing is a distally directed surface extending from the distal end of the housing into the distal opening. In this example, the plunger rod comprises a flexible arm protruding from the distal opening of the housing. In this example, the engaging member of the plunger rod is a proximally directed surface on the flexible arm.

In this example, the medicament delivery device with the sub-assembly can provide two medicament delivery shots (by releasing the plunger rod twice). For example, the first shot can be a priming shot for expelling any contained air within the medicament container M, or a mixing shot for mixing multiple contained substances within multiple chambers of the medicament container. The second shot is configured to deliver the contained medicament to a medicament delivery site of a patient.

In a preferred example, the sub-assembly comprises an outer shell1;1′ extending along the longitudinal axis L between a proximal end and a distal end, as shown inFIG.1,FIG.2andFIG.10. The outer shell1;1′ is configured to receive the medicament container M of the medicament delivery device. The housing3;3′ is axially immovably arranged within the outer shell1;1′. In this example, the sub-assembly comprises a safety member9removably attached to the distal end of the outer shell1′, as shown inFIG.10andFIG.12. In this example, a cut-out is arranged at the distal end of the outer shell1′. In this example, the safety member9comprises a support wall91protruding into the outer shell1′ through the cut-out of the outer shell1′ and configured to block the flexible arm34from flexing. In a preferred example, the safety member9comprises a user-accessible body90. The support wall91extends from a proximal side of the user-accessible body90into the cut-out of the distal end of the outer shell1′. A part of the user-accessible body90is configured to be attached on the outer shell1′, as shown inFIG.10, so that the user can easily remove the safety member9from the outer shell1′. In a preferred example, the cut-out of the outer shell1′ is arranged in the proximally directed wall of the outer shell1′.

In one example where the sub-assembly comprises the delivery member cover4, the tubular section40of the delivery member cover4is telescopic relative to the proximal end of the outer shell1′. In another example, the sub-assembly comprises a cap2configured to cover the proximal end of the delivery member cover. In a preferred example, the cap2is removably attached to the proximal end of the outer shell1′, so that an unintentional movement of the delivery member cover4towards the distal end of the housing3′ can be prevented.