Patent Application
20240001039
This application claims priority to European Patent Application No. 22305983.3 filed Jul. 1, 2022, the disclosure of which is hereby incorporated by reference in its entirety.
The present invention relates to a cap for an autoinjector, an autoinjector including said cap, and a method for assembling said autoinjector.
In this application, the distal end of a component or of a device is to be understood as meaning the end furthest from the user's hand and the proximal end is to be understood as meaning the end closest to the user's hand. Likewise, in this application, the “distal direction” is to be understood as meaning the direction away from the user's hand, and the “proximal direction” is to be understood as meaning the direction toward the user's hand.
Automatic injection devices are designed for automatic injection of a medical product into an injection site. Autoinjectors usually comprise a top body and a bottom body assembled to each other to form a housing. The bottom body is usually configured for receiving a medical container, such as a prefillable or prefilled syringe. The medical container has a barrel defining a reservoir for containing the medical product, the barrel having a distal end provided with an injection needle and an opened proximal end receiving a plunger rod for pushing a stopper. The injection needle is usually protected by a rigid needle shield removably secured to a distal tip of the medical container.
Autoinjectors also include a safety shield mechanism moving from an extended to a retracted position to respectively shield or unveil the needle and a power pack for automatically injecting the medical product into an injection site. The power pack is usually arranged inside the top body and includes a plunger rod for pushing a stopper inside the barrel of the medical container. An initially compressed spring is configured for moving the plunger in the distal direction. Locking means are provided for maintaining the plunger rod in an initial position in which the plunger rod is axially blocked despite the action of the compressed spring. A release member is further provided to release the plunger rod from the locking means and allow the spring to push the plunger rod in the distal direction to perform injection. A predetermined displacement of the safety shield towards the retracted position is required to allow the release member to unlock the locking means and release the plunger rod.
Assembly of the top body and the bottom body may be realized by any appropriate means such as snap-fitting or friction fit means. When fully assembled, a rattling noise may however be heard if a user shakes the autoinjector. This rattling noise is due to axial gaps that may exist between the powerpack and the medical container and between the power pack and the top body in the radial direction. As can be seen in
There is therefore a need for reducing these clearances and limiting the rattling noise.
The document US2022105278 discloses a cap provided at a distal end of an autoinjector. The cap includes a retainer for removing a needle shield. The retainer has radial protrusions for engaging an axial gap arranged between the needle shield and a distal shoulder of the syringe barrel. During assembly, it may happen that the needle shield is inserted too far inside the retainer. Thus, the radial protrusions outwardly deflect and rest against a lateral surface of the syringe barrel instead of engaging the axial gap. It is necessary to carry out a so-called “push back” step in which a the needle shield is moved back in the proximal direction. The push-back step enables the axial gap between the needle shield and the syringe barrel to move at the level of the radial protrusions so that the deformed radial protrusions move back inward in the axial gap and engage the needle shield. To that end, the known autoinjectors have an opened distal end providing access to the needle shield, thereby allowing to proximally push the needle shield. This opening at the distal end of the autoinjector is sometimes confusing for the end user who is generally not a skilled healthcare worker and who may believe that the injection needle will emerge from this central hole. It may happen that the end user forgets to remove the cap prior to injection.
There is therefore a need for a cap allowing to perform the push-back step and to avoid confusion for the end user.
An aspect of the invention is a cap for removing a needle shield attached to a medical container arranged inside a body of an autoinjector, the cap including:
As a result, the proximal abutment surface of the retainer pushes the medical container in the proximal direction. In turn, the medical container pushes the power pack against the body of the autoinjector. Thus, the axial clearances between the medical container, the power pack and the body of the autoinjector are suppressed or limited. The resulting rattling is also suppressed or limited.
The cap of the invention may further include some or all of the features below.
In an embodiment, the adjustment member includes a protrusion proximally extending from the proximal side of the sealing portion.
In an embodiment, the plug includes a single adjustment member.
The adjustment member may include two-diametrically opposite protrusions.
In an embodiment, the adjustment member includes a sloped surface configured to deform a distally extending resilient leg of the retainer.
In an embodiment, the adjustment member includes a resililently deformable element configured to exert a proximal pushing force on the retainer.
In an embodiment, the resiliently deformable member is in the form of a T-shaped blade.
In an embodiment, the plug further includes a push-back member for allowing to push the needle shield in a proximal direction.
In an embodiment, the push-back member is a through-hole extending through the sealing portion and configured to axially face a distal end of the needle shield.
In an embodiment, the push-back member includes a spring configured to push the needle shield in the proximal direction.
The adjustment member may include two proximal abutment surfaces and the push-back member is arranged between said two proximal abutment surfaces.
In an embodiment, the sealing portion is plate-shaped.
In an embodiment, the plug includes securing means for securing the plug to the housing. Thus, the plug is a separate component. The securing means are preferably configured to removably secure the plug to the housing.
In an alternative embodiment, the plug and the housing may be made of a single piece.
In an embodiment, the plug is made of a single piece.
Another aspect of the invention is an autoinjector including a cap having the aforementioned features.
Another aspect of the invention is a method for assembling said autoinjector, including the steps of:
The above steps may be carried out in any chronological order. For instance, step (i) may occur before step (ii). In this case, the push-back member of the plug may be a through-hole providing access to the distal end of the needle shield. In another instance, step (ii) may occur before step (i): this may be the case when the plug is devoid of any push-back member. In another embodiment, steps (i) and (ii) occur at the same time. The plug automatically performs the push-back step (ii) when attached to the cap. This may be the case when the adjustment member of the plug includes a spring which pushes the needle shield.
The invention and the advantages arising therefrom will clearly emerge from the detailed description that is given below with reference to the appended drawings as follows:
With reference to
The lower sub-assembly 2 includes a bottom body 20 for receiving a medical container 4, a cap 5 removably attached to a distal end 22 of the bottom body 20 and configured for removing a needle shield 6, a needle cover 24 axially movable along the longitudinal axis A with respect to the bottom body between a first extended position (pre-use position) in which the needle cover 24 at least partially or completely shields an injection needle, and a retracted position (injection position) proximally located relative to said first extended position, in which the needle cover 24 moves inside the autoinjector 1 to trigger the injection. Movement of the needle cover 24 from the first extended position to the retracted position is caused by a distal end of the needle cover 24 being pressed against an injection site during use of the autoinjector 1. The needle cover 24 is further movable from the retracted position to a second extended position (safety position) in which the needle cover 24 moves back in the distal direction so as to safely shield the injection needle. The lower sub-assembly 2 may further include a safety spring 26 for urging the needle cover 24 in the distal direction towards the safety position and locking means for locking the needle cover 24 in said safety position. The locking means may include a locking element, such as an abutment ring 28 configured to be fixed to the medical container 4, having a proximally extending resilient leg that engages a two-way slot arranged through the needle cover 24.
The medical container 4 has a tubular barrel 40 defining a reservoir for containing a medical product to be injected. The barrel 40 has a distal end in the form of a distal shoulder and a longitudinally protruding tip provided with an injection needle. A needle shield 6 is removably attached to said distal end for protecting and sealing the injection needle. Opposite its distal end, the barrel 40 has an opened proximal end surrounded by a flange 42. The opened proximal end is configured to receive a plunger rod 72 for pushing a stopper arranged inside the barrel 40. The medical container 4 may be a prefilled or prefillable syringe.
The top sub-assembly 3 includes a top body 30 arranged for receiving a power pack 7. The power pack 7 is the unit that stores the energy and contain the features necessary to hold and release said energy so as to expel the medical product from the medical container. The power pack 7 may include a holder 70, a plunger rod 72 and an injection spring 76 configured to push the plunger rod 72 in the distal direction to perform injection. The plunger rod 72 is axially movable between an initial position, in which the plunger rod 72 is blocked axially in spite of the action of the retracted injection spring 76, and a final position, distally located with regard to said initial position, in which injection is completed. In the initial position, the plunger rod 72 may be axially away from the stopper, but in the final position the plunger rod 72 is engaged with the stopper and the injection spring 76 has extended in such a way that the plunger rod 72 has pushed the stopper to the distal end of the barrel 40 and the medical product is expelled from the reservoir. The power pack 7 may include blocking means for blocking the plunger rod 72 in the initial position, said blocking means including for instance an axially movable blocking ring 78 configured to maintain or release blocking balls 780 arranged for engaging radial cavities of the plunger rod 72.
The holder 70 is configured for triggering the injection operation. The holder 70 is axially movable inside the top body 30 between an initial position, in which the autoinjector 1 stays inactive, and a triggering position, proximally located with regard to said initial position, in which the holder 70 releases the plunger rod 72 so that the autoinjector 1 becomes activated. In the initial position, the holder 70 may stay axially away from the blocking ring 78, but in the triggering position the holder 70 may have pushed the blocking ring 78 in the proximal direction such that the blocking 780 balls are no longer blocked inside the cavities of the plunger rod 72 and can move outside said cavities in such a way that the plunger rod 72 is released. The proximal movement of the holder 70 from the initial to the triggering position may be caused by the needle cover 24 abutting against the holder 70 when the needle cover 24 moves towards the retracted position.
The power pack 7 may, or may not, includes a locker 74 arranged for preventing inadvertent movement of the holder 70 to the triggering position. The locker 74 may be in the form of a rotatable ring arranged around the holder 70. The locker 74 is axially movable between a an initial position, in which a proximal abutment surface 740 of the locker 74 axially faces a distal abutment surface which may be defined by an axial rib 32 of the top body 30, and an intermediate blocking position, proximally located with regard to said initial position, in which said proximal abutment surface 740 of the locker 74 abuts against the distal abutment surface of the top body 30 such that the locker 74 and the holder 70 (which axially abuts against the locker 74) are blocked in the proximal direction and cannot transition towards the triggering position. This prevents inadvertent activation of the autoinjector 1. However, the locker 74 is further rotationally movable around the longitudinal axis A between said intermediate blocking position and a release position, in which the proximal abutment surface 740 of the locker 74 is circumferentially shifted away from the distal abutment surface of the top body 30 such that the locker 74 does not any longer block the holder 70 and allows said holder 70 to move towards the triggering position. Translation and then rotation of the locker 74 are caused by a proximal end 240 of the needle cover 24 abutting against a cam portion 742 of the locker 74.
The cap 5 includes a housing 50, a retainer 8 arranged inside the housing 50, and a plug 9 arranged at a distal end 51 of the housing 50 for at least partially closing the opened distal end 51 of the housing 50.
With reference to
With reference to
The cap 5 is configured so that withdrawal of the cap housing 50 from the bottom body 20 of the autoinjector 1 causes withdrawal of the needle shield 6 from the medical container 4 by means of the retainer 8. More specifically, due to the abutment between the lower axial shoulder 54 and the second abutment surface 863, the cap housing 50 drives the retainer 8 in the distal direction. The clamping member 81 of the retainer 8 engages the proximal end 60 of the needle shield 6. The needle is accordingly withdrawn from the medical container 4. As visible in
With reference to
The retainer 8 further has an opened distal end 84. The opening defined by said opened distal end 84 is configured for allowing the push-back step. The push-back step ends when the distal stop 810 abuts against the proximal end 60 of the needle shield 6. The distal end 84 of the retainer 8 is further configured to abut against the plug 9 so that the plug 9 can move the retainer 8 in the proximal direction when the plug 9 is assembled to the cap, as will be explained in further details below. More specifically, the distal end 84 of the retainer 8 may include at least one resilient leg 85 configured to abut against the plug 9.
The retainer 8 may be axially movable with respect to the cap housing 50 between a first position, in which the retainer 8 abuts against the upper axial shoulder 55 of the cap housing 50, and a second position, proximally located with regard to the first position, in which the retainer 8 abuts either against the lower axial shoulder 54 or against the bottom body 20 (
The retainer 8 includes a proximal abutment surface 87 configured to abut against the medical container 4 when the retainer 8 moves in the proximal direction. The proximal abutment surface 87 may be defined by the proximal side of the hooks forming the clamping member 81, while the distal side of these hooks defines the distal stop 810. The proximal abutment surface 87 of the retainer 8 permits to push the medical container 4, and consequently the power pack 7, in the proximal direction so that the power pack 7 abuts against the top body 30 of the autoinjector 1. This limits or cancels the axial clearances and the rattling noise. Movement of the retainer 8 in the proximal direction is caused by the plug 9.
With reference to
Still with reference to
The anti-rattling member 91 is configured to suppress the axial clearance between the power pack 7 and the medical container 4, thus cancelling the rattling noise that is due to said axial clearance. To that end, the anti-rattling member 91 is arranged at a proximal side 901 of the plug 9 for abutting against the retainer 8. The anti-rattling member 91 is intended to push the retainer 8 in the proximal direction when the plug 9 is secured to the cap housing 50. In turn, this causes the medical container 4 to move together with the retainer 8 in the proximal direction. Thus, the medical container 4 abuts against the power pack 7 and pushes the power pack 7 in abutment against the top body 30. The resilient legs 83 of the retainer 8 may then slightly deform in a radial outward direction until the proximal end 82 of retainer 8 abuts against the distal stop 21 of the bottom body 20; the clamping member 81 however remains engaged in the axial gap 10 and still faces the proximal end 60 of the needle shield 6. The anti-rattling member 91 thus axially maintains the medical container 4 against the power pack 7 and the power pack 7 against the top body 30 (as schematically illustrated in
In the embodiment of
The plug 9 may advantageously include a push-back member 92 for allowing to perform the push-back step, i.e. to push the needle shield 6 in the proximal direction until the distal stop 810 of the retainer 8 engages the axial gap 10 between the needle shield 6 and the syringe barrel 40 and thus faces the proximal end 60 of the needle shield 6. In the embodiment of
In the embodiment of
With reference to the embodiment illustrated in
As illustrated in the embodiment of
As visible in
It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22305983.3 | Jul 2022 | EP | regional |
