Passive safety device, injection device comprising the same, and method for manufacturing said injection device

The passive safety device comprises a sleeve having a proximal end configured to be secured to a distal tip of the injection device, a hub slidably mounted onto the sleeve between a pre-use position, an injection position wherein the hub is proximally located with regard to the pre-use position, and a safety position wherein the hub is distally located with regard to the injection position, a biasing element configured to urge the hub distally towards the safety position, and a protector configured to slide together with the hub relative to the sleeve between the pre-use position and the injection position. The safety device may be configured to block a distal movement of the protector when the hub is in the injection position so that the protector is prevented from sliding back together with the hub in a distal direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the United States national phase of International Application No. PCT/SG2020/050529 filed Sep. 16, 2020, and claims priority to European Patent Application No. 19197826.1 filed Sep. 17, 2019, the disclosures of which are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a passive needle safety device, an injection device, such as a prefilled syringe, comprising this passive needle safety device, and a method for manufacturing said injection device.

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 of injection, with respect to the passive safety device or injection device of the invention, and the “proximal direction” is to be understood as meaning the opposite direction to said direction of injection, that is to say the direction towards the user's hand.

Injection devices, such as pre-fillable or prefilled syringes, usually comprise a hollow body or barrel forming a container for a medical product. This body comprises a distal end in the form of a longitudinal tip defining an axial passageway through which the medical product is expelled from the container. The distal end is equipped with a needle that is designed to be inserted into the skin of a patient and through which the product to be injected passes to an injection site.

In order to minimize the risks of needle stick injuries, it is known to furnish the injection devices with a safety device that protects the needle after an injection. This safety device usually comprises a sleeve that slides relative to the distal end of the injection device and covers the needle after the withdrawal of the needle from the injection site.

The safety devices may be either active or passive. The active safety devices need to be activated by the user, i.e. they require the user to undertake a specific action so as to trigger the protection of the needle once the injection is completed. In contrast, the passive safety devices do not need a user to perform any action to ensure that the needle is protected once the injection is completed.

Description of Related Art

Document WO2011098831 discloses such a passive safety device. This safety device comprises a sleeve which is axially slidable between a needle protecting position and a non-protecting position. The proximal part of this sleeve is configured to deform radially outwardly so as to reach the non-protecting position. This deformation enables to store energy so that the proximal part of said sleeve acts as a spring urging the whole sleeve back to its initial protecting position once the needle is removed from the injection site. However, in order to achieve an effective spring effect, the proximal part of the sleeve needs to be deformed at its greatest extent. This involves that the needle to be inserted a quite long distance into the injection site. This may be stressful or harmful for a user. Besides, as noted above, the proximal part of the sleeve is configured to extend radially outward. This outward deformation renders the safety device quite radially cumbersome. Moreover, deformation of the sleeve is visible and may worry a user.

There is therefore a need for a more compact and easier to manufacture passive safety device, said safety device allowing a reliable protection of the needle once the injection is completed.

SUMMARY OF THE INVENTION

An aspect of the invention is a passive safety device comprising:a sleeve having a proximal end configured to be secured to a distal tip of the injection device;a hub slidably mounted onto the sleeve between a pre-use position, an injection position wherein the hub is proximally located with regard to the pre-use position, and a safety position wherein the hub is distally located with regard to the injection position,a biasing element configured to urge the hub distally towards the safety position, anda protector configured to slide together with the hub relative to the sleeve between the pre-use position and the injection position, the safety device further comprisingfirst blocking means configured to block a distal movement of the protector when the hub is in the injection position so that the protector is prevented from sliding back together with the hub in a distal direction, andsecond blocking means configured to block a proximal movement of the hub when the hub is in the safety position.

The needle safety device of the invention thus permits a reliable protection of the needle after an injection while being compact and easy to manufacture.

In this application, by “passive safety device” it is meant a needle safety device which does not require the user to undertake any action after injection so as to make the needle be protected after removal of the needle from an injection site.

In an embodiment, the first blocking means are first snapping means configured to make the protector be snapped with the sleeve when the hub reaches the injection position.

This provides a compact and easy to manufacture safety device.

In an embodiment, the first snapping means are provided on the protector.

This feature improves the compactness of the safety device.

In an embodiment, the first snapping means comprise at least one first resilient leg that is slidably engaged in a longitudinal slot of the sleeve when the hub moves from the pre-use position towards the injection position, said at least one first resilient leg being configured to radially deform against a distal side of a blocking member of the sleeve and abut a proximal side of said blocking member when the hub is in the injection position.

This provides a compact and easy to manufacture solution in order to block any distal movement of the protector when the hub is in the injection position.

In an embodiment, the second blocking means are second snapping means configured to make the hub be snapped when the hub reaches said safety position.

This provides a compact and easy to manufacture safety device.

In an embodiment, the second snapping means are provided on the protector.

This feature improves the compactness of the safety device.

In an embodiment, the second snapping means comprise at least one second resilient leg that is slidably engaged in a proximal slot of the hub when the hub moves from the injection position towards the safety position, said at least one resilient leg being configured to radially deform against a distal side of a blocking member of the hub and abut a proximal side of said blocking member when the hub is in the safety position.

This provides a compact and easy to manufacture solution in order to block any proximal movement of the hub once the hub reaches the safety position.

In an embodiment, the hub comprises a proximal pushing surface that defines a proximal end of the proximal slot of the hub, said proximal pushing surface being configured to abut against the at least one second resilient leg in order to cause said protector to slide together with the hub when the hub moves from the pre-use position to the injection position.

This improves the compactness of the safety device.

In an embodiment, the second snapping means comprise at least one longitudinal leg of the sleeve that is slidably engaged in a distal slot of the hub when the hub moves from the injection position towards the safety position, said at least one longitudinal leg being configured to radially deform against a distal side of a retaining member of the hub and to abut against a proximal side of said retaining member when the hub is in the safety position.

The longitudinal leg of the sleeve may comprise a radial protrusion that is configured to abut against a distal side of the retaining member of the hub in the pre-use position so as to retain the hub in this pre-use position against the action of the biasing element.

In an embodiment, the hub comprises at least one inner retaining element, such as a retaining hook, the biasing element comprises a distal end abutting against said inner retaining element in order to exert a distal force on the hub, and the sleeve has a longitudinal slot provided with an open distal end in order to allow said at least one retaining element to penetrate and slide into said longitudinal slot when the hub moves towards the injection position.

This improves the compactness of the safety device.

In an embodiment, the protector comprises a support ring, the first blocking means comprising at least one first resilient leg proximally extending from said support ring and the second blocking means comprising at least one second resilient leg distally extending from said support ring.

As a result, the first resilient legs and the second resilient legs are located at opposite sides of the support ring. This improves the compactness of the safety device.

In an embodiment, the at least one first resilient leg and the at least one second resilient leg are offset in a circumferential direction of the support ring.

As a result, the first resilient legs and the second resilient legs alternate along the support ring. This improves the compactness of the safety device.

In an embodiment, the protector is made of two parts configured to be assembled to each other directly on the hub.

This makes the safety device easier to manufacture. Each of the two parts that form the protector may correspond to a semi-circular half of said support ring. The two parts may be identical.

Another aspect of the invention is an injection device comprising the above-described passive safety device.

Another aspect of the invention is a method for manufacturing the above-described injection device, comprising the steps of:(i) securing the needle of the passive needle safety device onto a distal tip of the injection device;(ii) positioning the biasing element of the passive needle safety device into the sleeve;(iii) positioning the hub of the passive needle safety device onto the sleeve against the action of the biasing element;(iv) positioning the protector of the passive needle safety device onto the hub and the sleeve.

DETAILED DESCRIPTION

With reference toFIG.1is shown a passive safety device1according to an embodiment of the invention. The passive safety device1is configured to cover the needle102of an injection device100at the end of an injection, in order to prevent needle stick injuries.

The safety device1may adopt three successive positions: a pre-use position (FIGS.1,8,11) wherein the safety device1is ready to perform an injection, an injection position (FIGS.9,12) wherein the safety device1uncovers the needle to allow the needle102to enter an injection site, and a safety position (FIG.10,13) wherein the safety device1covers the needle102to prevent needle stick injuries. The pre-use position and the safety position may be identical or different.

With reference toFIGS.1,2,3A and3B, the safety device1comprises a sleeve2that is configured to be fixedly attached onto a distal tip104of the injection device100, a hub4that is slidably mounted on the sleeve2, a biasing element6urging the hub4in a distal direction, and a protector8that is slidably mounted onto the sleeve2. The safety device1further comprises first blocking means configured to block the protector8when the hub4reaches the injection position, and second blocking means configured to block the hub4when the hub4is in the safety position, as will be described in further details below.

The tubular sleeve2longitudinally extends along a longitudinal axis A. The sleeve2is configured to surround the distal tip104and a proximal part of the needle102. The sleeve2comprises a proximal end and an opposite distal end. The proximal end is configured to be secured onto the distal tip104of the injection device100, for example by gluing, screwing, interlocking, press-fitting, etc. The sleeve2comprises a blocking member, that may be located at the proximal end of the sleeve2and that may be in the form of a securing ring20. As visible onFIG.3A, the securing ring20defines a central through-opening204that accommodates the distal tip104. The securing ring20also has a proximal side and an opposite distal side. The distal side may define a slanted surface200. The proximal side may define an abutment surface202.

The sleeve2may further include one or several longitudinal legs22that are separated from each other by longitudinal slots24. The longitudinal legs22and the longitudinal slots24may extend parallel to the longitudinal axis A. The longitudinal slots24may be opened at their distal end and closed by the securing ring20at their proximal end. The longitudinal legs22may have a free distal end that may form the distal end of the sleeve2, and an opposite proximal end that may be connected to the securing ring20. The longitudinal legs22thus distally extend from said securing ring20. The longitudinal legs22may be regularly distributed along the securing ring20. The longitudinal legs22of the sleeve2may be configured to deflect radially inwardly. The longitudinal legs22may comprise a radial protrusion220, such as an outwardly extending radial protrusion220, whose function will appear hereinafter. This radial protrusion220may be located at the free distal end of the longitudinal legs22. The radial protrusion220has a proximal side, that may define a possibly slanted, deflecting and/or retaining surface222, and a distal side, that may define a blocking surface224.

With reference toFIGS.1,2and4, the hub4longitudinally extends along the longitudinal axis A. The hub4surrounds the sleeve2. More specifically, the hub4is slidably mounted onto the sleeve2along the axis A between the pre-use position (FIGS.1,8,11) wherein a distal end of the hub4may be configured to be distally located beyond a tip of the needle102so as to cover the needle102, the injection position (FIGS.9,12) wherein the hub4is proximally retracted relative to the pre-use position so that the hub4uncovers the needle102, and the safety position (FIGS.10,13) wherein the distal end of the hub4is configured to distally extend beyond the tip of the needle102, so that the hub4covers the needle102back in order to avoid needle stick injuries.

The tubular hub4has a distal end and an opposite proximal end. The distal end defines a central opening400that is configured to let the needle102extend through said opening40in order to perform the injection. The distal end of the hub4further comprises an abutment surface402configured to contact the injection site, such as typically the skin of a patient, and to push the hub4proximally towards the injection position as the needle102enters the injection site. The abutment surface402may encircle the opening400. As shown onFIG.4, the proximal end of the hub4defines an opening44that receives the sleeve2.

The hub4comprises a blocking member that may be located at the proximal end of the hub4. The blocking member may be in the form of a blocking ring46. Said blocking ring46has a proximal side and an opposite distal side. As best shown onFIG.4, the proximal side defines a blocking surface460. The distal side may define a slanted deflecting surface462.

The hub4comprises one or several proximal slots48extending parallel to the longitudinal axis A. The proximal slots48may extend above and be aligned with the longitudinal legs22of the sleeve2. The proximal slots48are closed at their proximal end by the blocking ring46. The proximal slots48may also be closed at their distal end by a pushing surface410, said pushing surface410being configured to push the protector8in the proximal direction when the hub4moves towards the injection position, so that the protector8slides together with the hub4towards the injection position.

The hub4may comprise one or several distal slots49that extend parallel to the longitudinal axis A. The distal slots49are aligned with the proximal slots48and are located distally relative to the proximal slots48. The distal slots49may be closed at their distal end by a distal ring40that may form the distal end of the hub4and thus delimits the central opening400and the abutment surface402. The distal slots49may be closed at their proximal end by a distal retaining surface412. The distal retaining surface412may be configured to abut against the radial protrusions220of the longitudinal legs22so as to maintain the hub4in the pre-use position against the force exerted by the biasing element6, prior to an injection. The proximal and/or distal slots48,49may be regularly distributed along a circumferential direction of the hub4.

The radial protrusions220of the sleeve2and the distal slots49of the hub4may also act as guiding means so as to guide the translation of the hub4relative to the sleeve2.

The hub4may comprise a retaining member that may be located at the distal end of the proximal slots48and/or at the proximal end of the distal slots49. The retaining member may be in form of an intermediate ring41that may separate the proximal slots48from the adjacent distal slots49. The intermediate ring41comprises a proximal side that may define the pushing surface410. The intermediate ring41comprises a distal side that may define the distal retaining surface412. Said distal retaining surface412may be slanted to favor an inward deformation of the longitudinal legs22of the sleeve2when said distal retaining surface412abuts against the radial protrusions220. Therefore, the radial protrusions220may disengage the distal slots49and engage the proximal slots48when the hub4is moved towards the safety position.

The hub4may comprise one or several retaining elements, such as hooks42, that may extend from an inner lateral wall of the hub4so as to provide a support for a distal end of the biasing element6. These retaining elements are configured to enter and slide along the longitudinal slots24of the sleeve2when the hub4moves towards the injection position, so that the biasing element6stores energy.

The biasing element6may be a spring whose distal end is connected to the hub4, for example by means of the inwardly protruding hooks42, and whose proximal end is secured in-between the sleeve2and the distal tip104.

With reference toFIGS.1,2and5, the protector8surrounds the sleeve2and is proximally located relative to the hub4. The protector8is configured to slide together with the hub4onto the sleeve2when the hub4moves from the pre-use position to the injection position. The protector8thus comprises a distal abutment surface820, said distal abutment surface820being configured to be pushed by a pushing surface410of the hub4.

The protector8is further configured and to be fixed relative to the sleeve2when the hub4moves from the injection position to the safety position. The safety device1thus comprises first blocking means configured to prevent the protector8from moving back in the distal direction when the hub4moves from the injection position to the safety position. The first blocking means may preferably be in the form of first snapping means that are configured to make the protector8get snapped with the sleeve2as soon as the hub4reaches the injection position.

The first snapping means may comprise first resilient legs81that are provided on the protector8. The first resilient legs81may extend parallel to the longitudinal axis A. They may be located above the longitudinal slots24of the sleeve2and may be aligned with said longitudinal slots24.

The free ends of the first resilient legs81are engaged in the longitudinal slots24of the sleeve2when the hub4is being moved from the pre-use position to the injection position. The first resilient legs81and the longitudinal slots24may thus act as guiding means for guiding the translation of the protector8relative to the sleeve2before the hub4reaches the injection position.

The first resilient legs81are configured to radially outwardly deform when abutting against the proximal side of the securing ring20of the sleeve2, so as to disengage the longitudinal slots24and pass behind said securing ring20.

The first resilient legs81may comprise a proximal deflecting surface810that may be slanted and that is intended to abut against the distal side of the securing ring20so as to favor the radial deformation of the first resilient legs81.

The first resilient legs81may comprise a distal abutment surface812that is configured to abut against the distal side of the securing ring20so as to block a distal movement of the protector8when the hub4is being moved from the injection position to the safety position.

The first resilient may further include a proximal abutment surface814configured to abut against, for example, a distal shoulder108of the injection device100, so as to block a proximal movement of the protector8when the protector8is in the injection position.

The first resilient legs81advantageously include a hook-shaped portion816that may be located at their free end, said hook-shaped portions816extending radially inwardly so as to engage the longitudinal slots24of the sleeve2before the hub4reaches the injection position, and said hook portions816disengaging said longitudinal slots24in order to be positioned proximally relative to the securing ring20when the hub4reaches the injection position. A distal side of the hook-shaped portions816may define the distal abutment surface812. A proximal side of the hook-shaped portions816may define the deflecting surface810and/or the proximal abutment surface814.

It should be noted that the safety device1might be configured to maintain a distance between the proximal end of the hub4, more specifically the blocking surface460, and the distal abutment surface812of the first resilient legs81.

The safety device1further comprises second blocking means configured to prevent the hub4from moving back in the proximal direction after the hub4reaches the safety position. The second blocking means may be in the form of second snapping means that are configured to make the hub4be snapped with the protector8and/or the sleeve2as soon as the hub4reaches the safety position.

The second snapping means may comprise second resilient legs82that are provided on the protector8. The second resilient legs82may extend parallel to the longitudinal axis A. They may be aligned with the proximal slots48of the hub4.

The free ends of second resilient legs82are engaged in the proximal slots48of the hub4when the hub4is being moved from the pre-use position to the injection position. The second resilient legs82and the proximal slots48may thus act as guiding means for guiding the translation of the hub4relative to the protector8before the hub4reaches the safety position.

The second resilient legs82are configured to radially outwardly deform when abutting against the proximal side of the blocking ring46of the hub4, so as to disengage the proximal slots48and pass behind said blocking ring46.

The second resilient legs82may comprise a proximal deflecting surface822that may be slanted and that is intended to abut against the blocking ring46so as to favor the radial deformation of the second resilient legs82.

The second resilient legs82may comprise a distal abutment surface820that is configured to abut against the distal side of the blocking ring46so as to block a proximal movement of the hub4once the hub4is in the safety position. It should be noted that the distal abutment surface of the second resilient legs82advantageously corresponds to the distal abutment surface820that is pushed by the pushing surface410of the hub4.

The second resilient legs82advantageously include a hook-shaped portion824that may be located at their free end, said hook-shaped portions824radially inwardly extending in the proximal slots48of the hub4before the hub4reaches the safety position, and disengaging said proximal slots48in order to be positioned proximally relative to the blocking ring46when the hub4reaches the safety position. A distal side of the hook-shaped portions824may define the distal abutment surface820. A proximal side of the hook portions may define the proximal deflecting surface822.

It is contemplated that the second snapping means may alternatively or complementarily comprise the longitudinal legs22of the sleeve2that may pass behind the intermediate ring41of the hub4when the hub4reaches the safety position, the blocking surface224of the radial protrusion220abutting against the proximal side of the intermediate ring41, thereby preventing the hub4from being translated back in the proximal direction when the hub4is in the safety position.

The protector8advantageously comprises a support ring80that surrounds the hub4and that both supports the first and the second resilient legs81,82. More specifically, the first resilient legs81proximally extend from said support ring80while the second resilient legs82distally extend from said support ring80. The first resilient legs81and the second resilient legs82may be offset in a circumferential direction of the support ring80, thereby alternating along the circumference of the support ring80. The first and second resilient legs81,82may be regularly distributed along the support ring80.

With reference toFIGS.2and6, the protector8may be made of two parts8a,8bassembled to each other, each of said parts8a,8bcorresponding to a semi-circular half of said support ring80. As a result, the two halves of the protector8may be assembled directly around the hub4. The two parts8a,8bmay be identical. More specifically, the two parts8a,8bmay comprise snapping means so as to be secured to each other. The snapping means may comprise an axial slot84configured to receive an axial rib86provided on the other part, and an axial rib86configured to engage the axial slot84of said other part. The two parts8a,8bof the protector8may further comprise guiding means, such as a rod88configured to enter a hole89of the other part and a hole89configured to receive a rod88of said other part. The guiding means may be orthogonal to the longitudinal axis A and orthogonal to the bond line of said two parts8a,8b.

With reference toFIGS.1and2, the invention also relates to an injection device100, such as a prefilled or prefillable syringe, comprising a barrel106defining a reservoir for a medical product, a distal tip104defining a passageway in communication with the reservoir and a needle102secured to the distal tip104so as to allow said medical product to be injected into an injection site. The injection device100further comprises a passive safety device1as above described, said safety device1being secured onto the distal tip104.

The barrel106defines a distal shoulder108that delimits with the sleeve2a groove intended to receive the first blocking means when the hub4reaches the injection position. The distal shoulder108may block a proximal movement of the protector8relative to the sleeve2, thereby preventing a proximal movement of the hub4relative to the sleeve2when the hub4is blocked in the safety position by the distal abutment surface820of the protector8.

With reference toFIGS.7A and7B, the injection device100may further comprise a cap110configured to be mounted onto the safety device1. The cap110may be made of two different materials, for example a first inner material111such as rubber or TPE and a second outer material112such as polycarbonate. The first material111may be soft while the second material112may be rigid. The inner material111may extend through one or more grooves of the second material112so as to provide one or more gripping surfaces114on an external lateral wall of the cap110. The inner material111may have a portion116pricked by the needle when the cap is mounted on the safety device1. This portion116may be surrounded by an inner protective sleeve118that may be made of the second material112. The cap110defines a cavity120configured to accommodate the safety device1. The cap110is configured to be removed by simply pulling the cap110in the distal direction.

The operation of the safety device1and the injection device100of the invention is described below with reference toFIGS.8to10and11to13.

The user may firstly remove the cap110by pulling the cap110along the longitudinal axis A in the distal direction. The safety device1is in the pre-use position as shown onFIGS.8and11.

The user may then apply the distal end of the hub4on the injection site and press the injection device100against the injection site (FIG.11). This causes the hub4to slide proximally from the pre-use position to the injection position and the needle102to enter the injection site. Due to the pushing surface410of the hub4abutting against the distal abutment surface820of the protector8, the protector8slides together with the hub4in the proximal direction relative to the sleeve2. The distal end of the sleeve2distally slides in the distal slots49of the hub4. The first resilient legs81proximally slide in the longitudinal slots24of the sleeve2. The biasing element6is compressed due to the retaining element moving in the proximal direction and thus stores energy.

When the hub4reaches the injection device100, the free ends of the first resilient legs81abut against the distal side of the securing ring20and radially deform so as to move behind said securing ring20. The hook-shaped portion814of the first resilient legs81is thus blocked between the proximal side of the securing ring20and the distal shoulder108of the barrel106, thereby preventing the protector8from moving in the distal and proximal directions (FIGS.9and12).

When the injection is completed, the user withdraws the needle102from the injection by pulling the injection device100away from the injection site. The biasing element6thus releases its stored energy, thereby causing the hub4to slide back relative the sleeve2from the injection position towards the safety position in the distal direction. The protector8however remains in the injection position, due to the abutment of the distal abutment surface812of the hook-shaped portion814against the abutment surface202of the securing ring20. The second resilient legs82accordingly slide into the proximal slots48in the proximal direction.

When the hub4reaches the safety position, the free ends of the second resilient legs82abut against the distal side of the blocking ring46of the hub4and thus radially deform so as to move behind said blocking ring46. The free ends of the longitudinal legs22of the sleeve2may, before or simultaneously, abut against the distal side of the intermediate ring41and deform radially inwardly so as to move behind said intermediate ring41. Due to the abutment of the proximal side of the blocking ring46against the distal abutment surface820of the free end of the second resilient legs82and/or to the abutment of the proximal side of the intermediate ring41against the blocking surface224of the free ends of the longitudinal legs22, the hub4is prevented from moving back in the proximal direction. The hub4in the safety position thus protects the needle102and avoids needle stick injuries.

The invention also relates to a method for manufacturing the above-described injection device100, this method comprising the steps of:(i) securing the needle onto a distal tip104of the injection device100;(ii) positioning the biasing element6into the sleeve2;(iii) positioning the hub4onto the sleeve2against the action of the biasing element6;(iv) positioning the protector8onto the hub4and the sleeve2.

The steps (ii) and (iii) may take place simultaneously.

The step (iii) may comprise the pre-loading of the biasing element6until the distal end of the leg of the sleeve2abuts against the distal side of the intermediate ring41of the hub4.

The step (iv) may comprise the step of assembling the two-part protector8directly around the hub4and the sleeve2. By assembling the two-part protector8directly around the hub4and the sleeve2it should be understood that the result of this assembly is the protector8being assembled and positioned onto the hub4and the sleeve2in a ready for use condition. This step may be performed by means of the above-described snapping and/or guiding means of the two halves of the protector8.