Autoinjector

Abstract

An autoinjector includes a case adapted to hold a medicament container having a needle, a needle shroud telescopically coupled to the case, and a plunger rotationally and slidably disposed in the case. The needle shroud is movable between a first extended position relative to the case in which the needle is covered and a retracted position relative to the case in which the needle is exposed. The plunger is rotatable relative to the case between a first rotational position in which the plunger is engaged to the case and a second rotational position in which the plunger disengages the case. The needle shroud is operably coupled to the plunger. When the needle shroud translates from the first extended position to the retracted position, the plunger rotates from the first rotational position to the second rotational position.

Description

TECHNICAL FIELD

The invention relates to an autoinjector.

BACKGROUND

Administering an injection is a process which presents a number of risks and challenges for users and healthcare professionals, both mental and physical. Injection devices typically fall into two categories—manual devices and autoinjectors. In a conventional manual device, manual force is required to drive a medicament through a needle. This is typically done by some form of button/plunger that has to be continuously pressed during the injection. There are numerous disadvantages associated with this approach. For example, if the button/plunger is released prematurely, the injection will stop and may not deliver an intended dose. Further, the force required to push the button/plunger may be too high (e.g., if the user is elderly or a child). And, aligning the injection device, administering the injection and keeping the injection device still during the injection may require dexterity which some patients (e.g., elderly patients, children, arthritic patients, etc.) may not have.

Autoinjector devices aim to make self-injection easier for patients. A conventional autoinjector may provide the force for administering the injection by a spring, and trigger button or other mechanism may be used to activate the injection. Autoinjectors may be single-use or reusable devices.

There remains a need for an improved autoinjector.

SUMMARY

It is an object of the present invention to provide an improved autoinjector.

In an exemplary embodiment, an autoinjector according to the present invention comprises a case adapted to hold a medicament container having a needle, a needle shroud telescopically coupled to the case and movable between a first extended position relative to the case in which the needle is covered and a retracted position relative to the case in which the needle is exposed, and a plunger rotationally and slidably disposed in the case. The plunger is rotatable relative to the case between a first rotational position in which the plunger is engaged to the case and a second rotational position in which the plunger disengages the case. The needle shroud is operably coupled to the plunger. When the needle shroud translates from the first extended position to the retracted position, the plunger rotates from the first rotational position to the second rotational position.

In an exemplary embodiment, the needle shroud is movable from the retracted position to a second extended position relative to the case in which the needle is covered and the needle shroud cannot translate relative to the case.

In an exemplary embodiment, the autoinjector further comprises a cap removably coupled to the case. The cap may include an element adapted to engage a protective needle sheath removably disposed on the needle. The cap may include at least one compliant beam adapted to releasably engage at least one radial aperture in the needle shroud. When the cap is coupled to the case the at least one compliant beam engages the at least one radial aperture in the needle shroud and radially abuts the case. When the cap is removed from the case, the at least one compliant beam disengages the at least one radial aperture in the needle shroud and no longer radially abuts the case.

In an exemplary embodiment, the autoinjector further comprises a shroud spring biasing the needle shroud in a distal direction relative to the case.

In an exemplary embodiment, the autoinjector further comprises a drive spring biasing the plunger in a distal direction relative to the case. The plunger translates relative to the case under force of the drive spring when the plunger is in the second rotational position and the needle shroud is in the retracted position. The plunger may be at least partially hollow and the drive spring may be at least partially disposed within the plunger.

In an exemplary embodiment, the needle shroud includes at least one compliant shroud beam radially abutting the case when the needle shroud is in the first extended position and the retracted position, and the at least one compliant shroud beam deflects radially when the needle shroud is in the second extended position and axially abuts the case.

In an exemplary embodiment, the plunger includes a first plunger boss adapted to engage a shroud rib disposed on the needle shroud and a second plunger boss adapted to engage a case slot in the case. When the plunger is in the first rotational position and the needle shroud is in the first extended position, the first plunger boss engages the shroud rib and the second plunger boss engages the case slot. When the needle shroud translates from the first extended position to the retracted position, the plunger rotates from the first rotational position to the second rotational position and the second plunger boss disengages the case slot. The shroud rib maintains the plunger in the first rotational position when the needle shroud is in the first extended position.

The needle shroud may include a receiving element adapted to receive the first plunger boss when the needle shroud is in the retracted position and the plunger is in the second rotational position.

In an exemplary embodiment, when the needle shroud translates from the first extended position to the retracted position, the shroud rib engages a plunger rib to rotate the plunger from the first rotational position to the second rotational position. The plunger rib may be disposed at an angle relative to a longitudinal axis of the case.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1A is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 1B is a schematic side view of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 2 is a schematic view of an exemplary embodiment of a shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention,

FIG. 3 is a perspective exploded view of an exemplary embodiment of a control subassembly of an exemplary embodiment of an autoinjector according to the present invention,

FIG. 4 is a perspective exploded view of an exemplary embodiment of a drive subassembly of an exemplary embodiment of an autoinjector according to the present invention,

FIG. 5 is a perspective view of an exemplary embodiment of a needle sheath removal mechanism of an exemplary embodiment of an autoinjector according to the present invention,

FIG. 6 is a schematic view of an exemplary embodiment of a plunger release mechanism of an exemplary embodiment of an autoinjector according to the present invention,

FIG. 7 is a schematic view of an exemplary embodiment of a plunger release mechanism of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 8 is a schematic view of an exemplary embodiment of a plunger release mechanism of an exemplary embodiment of an autoinjector according to the present invention after assembly,

FIG. 9 is a schematic view of an exemplary embodiment of a shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention after assembly,

FIG. 10 is a schematic view of an exemplary embodiment of shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 11 is a schematic view of an exemplary embodiment of shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 12 is a schematic view of an exemplary embodiment of shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 13 is a schematic view of an exemplary embodiment of shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention during assembly,

FIG. 14 is a schematic view of an exemplary embodiment of shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention after assembly,

FIG. 15A is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention after assembly,

FIG. 15B is a schematic side view of an exemplary embodiment of an autoinjector according to the present invention after assembly,

FIG. 16 is a schematic view of an exemplary embodiment of a shroud lock mechanism an exemplary embodiment of an autoinjector according to the present invention prior to use,

FIG. 17A is a longitudinal section of an exemplary embodiment of a shroud lock mechanism an exemplary embodiment of an autoinjector according to the present invention prior to use,

FIG. 17B is a schematic side view of an exemplary embodiment of a shroud lock mechanism an exemplary embodiment of an autoinjector according to the present invention prior to use,

FIG. 18A is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use,

FIG. 18B is a schematic side view of an exemplary embodiment of an autoinjector according to the present invention during use,

FIG. 19 is a schematic view of an exemplary embodiment of a plunger release mechanism of an exemplary embodiment of an autoinjector according to the present invention during use,

FIG. 20A is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use,

FIG. 20B is a schematic side view of an exemplary embodiment of an autoinjector according to the present invention during use,

FIG. 21A is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention after use,

FIG. 21B is a schematic side view of an exemplary embodiment of an autoinjector according to the present invention after use,

FIG. 22 is a schematic view of an exemplary embodiment of a shroud lock mechanism of an exemplary embodiment of an autoinjector according to the present invention after use, and

FIGS. 23A-E is a schematic view of another exemplary embodiment of a plunger release mechanism during assembly and before, during and after use.

Corresponding parts are marked with the same reference symbols in all figures.

DETAILED DESCRIPTION

FIG. 1A is a longitudinal section of an exemplary embodiment of an autoinjector 1 according to the present invention during assembly. The autoinjector 1 comprises a case 2 comprising a front case 2.1 and a rear case 2.2 (e.g., a part). The case 2 is adapted to hold a medicament container, such as a syringe 3. The syringe 3 may be a pre-filled syringe and have a needle 4 arranged at a distal end. When the autoinjector 1 and/or the syringe 3 are assembled, a protective needle sheath 5 may be removably coupled to the needle 4. The protective needle sheath 5 may be a rubber needle sheath or a rigid needle sheath (which is composed of rubber and a full or partial plastic shell). A stopper 6 is arranged for sealing the syringe 3 proximally and for displacing a medicament M contained in the syringe 3 through the needle 4. In other exemplary embodiments, the medicament container may be a cartridge which includes the medicament M and engages a removable needle (e.g., by threads, snaps, friction, etc.).

In an exemplary embodiment, a cap 11 may be removably disposed at a distal end of the case 2. The cap 11 may include an element (e.g., a barb, a hook, a narrowed section, etc.) arranged to engage the protective needle sheath 5, the case 2 and/or a needle shroud 7 telescoped within the case 2. The cap 11 may comprise grip features 11.5 for facilitating removal of the cap 11 (e.g., by twisting and/or pulling the cap 11.5 relative to the case 2).

In an exemplary embodiment, a shroud spring 8 is arranged to bias the needle shroud 7 in a distal direction D against the case 2. In an exemplary embodiment, the needle shroud includes a cylindrical collar 7.12, an annular flange 7.13, and a pair of first arms 7.14.

In an exemplary embodiment, a drive spring 9 is arranged within the case 2. A plunger 10 serves for forwarding a force of the drive spring 9 to the stopper 6. In an exemplary embodiment, the plunger 10 is hollow and the drive spring 9 is arranged within the plunger 10 biasing the plunger 10 in the distal direction D against the case 2. In another exemplary embodiment, the plunger 10 may be solid and the drive spring 9 may engage a proximal end of the plunger 10.

In an exemplary embodiment, a plunger release mechanism 12 is arranged for preventing release of the plunger 10 prior to retraction of the needle shroud 7 relative to the case 2 and for releasing the plunger 10 once the needle shroud 7 is sufficiently retracted.

In an exemplary embodiment, a first shroud lock mechanism 14 is arranged to prevent retraction of the needle shroud 7 relative to the case 2 when the cap 11 is in place, thereby avoiding unintentional activation of the autoinjector 1 (e.g., if dropped, during shipping or packaging, etc.). The first shroud lock mechanism 14 may comprise one or more compliant beams 11.3 on the cap 11 and a respective number of apertures 7.6 in the needle shroud 7 adapted to receive each of the compliant beams 11.3. When the cap 11 is attached to the autoinjector 1, the compliant beams 11.3 abut a radial stop 2.15 on the case 2 which prevents the compliant beams 11.3 from disengaging the apertures 7.6. When the cap 11 is attached to the autoinjector 1, axial movement of the cap 11 in the proximal direction P relative the case 2 is limited by a rib 11.4 on the cap 11 abutting the case 2. When the cap 11 is pulled in the distal direction D relative to the case 2, the compliant beams 11.3 may abut an edge of the aperture 7.6 and deflect to disengage the aperture 7.6, allowing for removal of the cap 11 and the protective needle sheath 5 attached thereto. In an exemplary embodiment, the compliant beams 11.3 and/or the apertures 7.6 may be ramped to reduce force necessary to disengage the compliant beams 11.3 from the apertures 7.6.

FIG. 1B is a schematic side view of an exemplary embodiment of the autoinjector 1 according to the prevent invention during assembly. In the exemplary embodiment in FIG. 1B, the case 2 is removed for clarity. FIG. 1B and FIG. 2 show a second shroud lock mechanism 15 that is adapted to lock the needle shroud 7 in an axial position relative to the case 2 after the autoinjector 1 has been removed from the injection site. In an exemplary embodiment, the second shroud lock mechanism 15 comprises at least one compliant shroud beam 7.1 (e.g., a pair of resilient arms) on the needle shroud 7 adapted to proximally abut a stop 2.12 on the case 2 after the autoinjector 1 has been removed from the injection site. The abutment of the shroud beam 7.1 on the stop 2.12 prevents translation of the needle shroud 7 in the proximal direction P relative to the case 2. In some examples, an axial length of the pair of first arms 7.14 is more than twice as long as (e.g., more than three times as long as, or more than four times as long as) an axial length of the pair of resilient arms 7.1. Prior to use, when the cap 11 is attached to the autoinjector 1, the cap 11 is adapted to engage and deflect the compliant shroud beam 7.1 radially inward, allowing the shroud beam 7.1 to pass the stop 2.12 in the proximal direction P so that the needle shroud 7 can translate in the proximal direction P relative to the case 2.

In an exemplary embodiment, the autoinjector 1 may formed from at least two subassemblies, e.g., a control subassembly 1.1 and a drive subassembly 1.2, to allow for flexibility as to the time and location of manufacture of the subassemblies 1.1, 1.2 and final assembly with the syringe 3.

FIG. 3 is a perspective exploded view of an exemplary embodiment of a control subassembly 1.1 of an autoinjector 1 according to the present invention. In an exemplary embodiment, the control subassembly 1.1 comprises the cap 11, the needle shroud 7, the shroud spring 8 and the front case 2.1. To assemble the control subassembly 1.1, the shroud spring 8 is inserted into the needle shroud 7, and the needle shroud 7 with the shroud spring 8 is inserted into the front case 2.1. The cap 11 is arranged over the distal end of the needle shroud 7.

FIG. 4 is a perspective exploded view of an exemplary embodiment of a drive subassembly 1.2 of an autoinjector 1 according to the present invention. In an exemplary embodiment, the drive subassembly 1.2 the plunger 10, the drive spring 9 and the rear case 2.2. Those of skill in the art will understand that if the viscosity or volume, for example, of the medicament M in the syringe 3 is changed, only parts of the drive subassembly 1.2 may need to be changed. To assemble the drive subassembly 1.2, the drive spring 9 is inserted into the plunger 10 and the plunger 10 is inserted in the rear case 2.2 in the proximal direction P thereby compressing the drive spring 9. Once the plunger 10 and the drive spring 9 reach a compressed position it is rotated by an angle, e.g. approximately 30° relative to the rear case 2.2, to engage the plunger 10 to the rear case 2.2. In an exemplary embodiment, the rear case 2.2 may have a cam surface to engage the plunger 10 to induce this rotation prior to the plunger 10 and the drive spring 9 reaching the compressed position.

FIG. 5 is a perspective view of an exemplary embodiment of a needle sheath removal mechanism 13 of an autoinjector 1 according to the present invention. The needle sheath removal mechanism 13 comprises an opening 11.1 axially arranged in the cap 11. The opening 11.1 is approximately sized and shaped to receive the protective needle sheath 5. One or more bosses 11.2 may be disposed on a proximal end of the cap 11 and adapted to abut the protective needle sheath 5. For example, when the protective needle sheath 5 is inserted into the opening 11.1, the protective needle sheath 5 may deform around the bosses 11.2. The bosses 11.2 may be ramped to reduce force necessary to insert the protective needle sheath 5 into the opening 11.1.

Once the protective needle sheath 5 has passed the bosses 11.2 in the distal direction D, the bosses 11.2 may abut a proximal end of the protective needle sheath 5 to prevent translation of the protective needle sheath 5 in the proximal direction P relative to the cap 11. For example, during removal of the cap 11 from the autoinjector 1, the bosses 11.2 on the cap 11 may abut the proximal end of the protective needle sheath 5 and push the protective needle sheath 5 in the distal direction D off of the needle 4, with their non-ramped distal face. Those of skill in the art will understand that a number of parameters can be varied, e.g. a radial height of the boss 11.2, an axial length of the boss 11.2, an angle of the ramp of the boss 11.2, a durometer of the protective needle sheath 5, a surface finish of the boss 11.2, etc., which could increase or decrease assembly forces, cap removal forces, etc.

FIG. 6 is a schematic view of an exemplary embodiment of a plunger release mechanism 12 of the autoinjector 1 according to the present invention during assembly. The plunger release mechanism 12 is arranged for preventing release of the plunger 10 prior to retraction of the needle shroud 7 relative to the case 2 and for releasing the plunger 10 once the needle shroud 7 is sufficiently retracted. In an exemplary embodiment, the plunger release mechanism 12 comprises the plunger 10, the rear case 2.2, and the needle shroud 7 interacting with each other. In an exemplary embodiment, the needle shroud 7 is limited to axial movement relative to the case 2, and the plunger 10 can translate axially and rotate relative to the case 2.

In an exemplary embodiment, the plunger 10 comprises a first plunger boss 10.1 adapted to engage a shroud rib 7.7 (e.g., protrusion) on the needle shroud 7, a second plunger boss 10.2 adapted to engage a case slot 2.3 in the case 2, and a plunger rib 10.3 adapted to engage the shroud rib 7.7 on the needle shroud 7. In an exemplary embodiment, the shroud rib 7.7 comprises a proximal face 7.8 adapted to engage the plunger rib 10.3, and a distal face 7.9 and a longitudinal face 7.10 adapted to engage the first plunger boss 10.1. A receiving element (e.g., a recess, a hole, etc.) may be formed on the needle shroud 7 distal of the longitudinal face 7.10 of the shroud rib 7.7. In an exemplary embodiment, the case slot 2.3 comprises a first angled surface 2.9 adapted to apply a rotational force in a first rotational direction R1 to the second plunger boss 10.2, a wall 2.10 adapted to abut the second plunger boss 10.2 to limit rotation of the plunger 10 relative to the case 2 in the first rotational direction R1, and a second angled surface 2.11 adapted to apply a rotational force in a second rotational direction R2, opposite the first rotational direction R1, to the second plunger boss 10.2.

In an exemplary embodiment of an assembly process of the drive subassembly 1.2, the plunger 10 with the drive spring 9 is inserted into the rear case 2.2. When the second plunger boss 10.2 is axially aligned with the case slot 2.3, the plunger 10 is rotated in the first rotational direction R1 until the second plunger boss 10.2 is moved into the case slot 2.3 until it abuts the wall 2.10. In this position, the first angled surface 2.9 prevents the second plunger boss 10.2 from moving in the second rotational direction R2, and thus prevents the plunger 10 from rotating relative to the case 2.

After a syringe 3 (with the protective needle sheath 5 disposed on the needle 4) is inserted into the control assembly 1.1, the drive subassembly 1.2 is coupled to the control subassembly 1.1. In an exemplary embodiment, a pair of resilient beams 2.13 (shown in FIG. 1B) on the rear case 2.2 is adapted to snap into recesses 2.14 (shown in FIG. 3) in the front case 2.1 to lock the drive subassembly 1.2 to the control subassembly 1.1. As the drive assembly 1.2 is coupled to the control subassembly 1.1, the needle shroud 7 translates proximally (e.g., by use of an assembly jig) causing the shroud rib 7.7 to abut the plunger rib 10.3. As shown in FIG. 7, as the shroud rib 7.7 pushes plunger rib 10.3, the angle of the plunger rib 10.3 causes the plunger 10 to rotate relative to the case 2 in the second rotational direction R2, and the second plunger boss 10.2 rides along the first angled surface 2.9 onto the second angled surface 2.11. When the second plunger boss 10.2 is disposed on the second angled surface 2.11, the force of the drive spring 9 imparts a rotational force on the plunger 10 in the second rotational direction R2 due to the angle of the second angled surface 2.11.

As shown in FIG. 8, when the needle shroud 7 is released (e.g., by removing the assembly jig), the needle shroud 7 translates in the distal direction D relative to the case 2 under the force the shroud spring 8 until the shroud rib 7.7 abuts the first plunger boss 10.1. For example, the distal face 7.9 of the shroud rib 7.7 may abut the first plunger boss 10.1 and maintain the needle shroud 7 in an axial position relative to the case 2. The second plunger boss 10.2 is prevented from disengaging the case slot 2.3, because the shroud rib 7.7 prevents the plunger 10 from rotating in the second rotational direction R2 relative to the case 2. For example, the longitudinal face 7.10 of the shroud rib 7.7 abuts the first plunger boss 10.1 to prevent rotation of the plunger 10.

FIG. 9 shows an exemplary embodiment of the first shroud lock mechanism 14 for an autoinjector 1 according to the present invention after assembly of the control subassembly 1.1. The compliant beam 11.3 on the cap is engaged in the aperture 7.6 within the needle shroud 7. The radial stop 2.15 is axially spaced from the compliant beam 11.3.

FIG. 10 shows an exemplary embodiment of the first shroud lock mechanism 14 for an autoinjector 1 according to the present invention during insertion of the syringe 3 into the control subassembly 1.1 for engaging the protective needle sheath 5 to the cap 11. The aperture 7.6 provides some clearance allowing a movement of the needle shroud 7 relative to the cap 11 in the distal direction D. The front case 2.1 is also moved in the distal direction D relative to the cap 11 axially aligning the radial stop 2.15 with the compliant beam 11.3 preventing the cap 11 from disengaging the needle shroud 7.

FIG. 11 shows an exemplary embodiment of the first shroud lock mechanism 14 for an autoinjector 1 according to the present invention, wherein after insertion of the syringe 3, the needle shroud 7 is moved further in the proximal direction P relative to the front case 2.1 by an assembly jig (not illustrated). In this state, the drive subassembly 1.2 may be assembled to the control subassembly 1.1. The compliant beam 11.3 remains engaged in the aperture 7.6 and the radial stop 2.15 prevents them from disengaging.

After assembly of the drive subassembly 1.2 to the control subassembly 1.1, the assembly jig is removed allowing the needle shroud 7 to move back in the distal direction D relative to the front case 2.1 under the force of the shroud spring 8 arriving again in the state illustrated in FIG. 10. In this configuration, the needle shroud 7 is prevented from moving in the proximal direction P relative to the case 2, because the radial stop 2.15 prevents the compliant beam 11.3 from disengaging the aperture 7.6 and the rib 11.4 on the cap 11 proximally abuts the front case 2.1.

FIG. 12 shows an exemplary embodiment of the second shroud lock mechanism 15 for an autoinjector 1 according to the present invention after assembly of the control subassembly 1.1. The needle shroud 7 is partially inserted into the cap 11. The shroud beam 7.1 is in a non-deflected position proximally abutting the stop 2.12 in the front case 2.1. This prevents the needle shroud 7 from moving further in the proximal direction P relative to the front case 2.1 and keeps the control subassembly 1.1 locked together.

FIG. 13 shows an exemplary embodiment of the second shroud lock mechanism 15 for an autoinjector 1 according to the present invention during insertion of the syringe 3 into the control subassembly 1.1, wherein the needle shroud 7 is moved further in the distal direction D into the cap 11 such that the cap 11 radially inwardly deflects the shroud beam 7.1 out of its abutment with the stop 2.12. The needle shroud 7 is thus free to move in the proximal direction P relative to the front case 2.1.

FIG. 14 shows an exemplary embodiment of the second shroud lock mechanism 15 for an autoinjector 1 according to the present invention after final assembly of the drive subassembly 1.2 to the control subassembly 1.1. The needle shroud 7 has been moved further in the proximal direction P relative the front case 2.1 by an assembly jig (not illustrated). In this state, the drive subassembly 1.2 may be assembled to the control subassembly 1.1. Subsequently, the assembly jig is removed and the needle shroud 7 translates in the distal direction D relative to the front case 2.1 under the force of the shroud spring 8 until the shroud rib 7.7 abuts the first plunger boss 10.1. The shroud beam 7.1 is prevented from deflecting radially outward by the stop 2.12 in the front case 2.1.

FIG. 15A is a longitudinal section of an exemplary embodiment of an autoinjector 1 according to the present invention after final assembly, and FIG. 15B is a schematic side view of an exemplary embodiment of an autoinjector 1 according to the present invention after final assembly, wherein the case 2 is removed for clarity.

In an exemplary embodiment, after the final assembly of the drive subassembly 1.2 to the control subassembly 1.1, the autoinjector 1 may be kept in temperature controlled environment (e.g., cold chain storage) to, for example, reduce creep in highly stressed components, e.g. under load from the drive spring 9.

An exemplary sequence of operation of an exemplary embodiment of the autoinjector 1 is as follows:

If applicable, the autoinjector 1 is removed from the packaging. The medicament in the syringe 3 may be visually inspected through a viewing window (not shown), which can be a transparent part of the case 2 or a cut-out in the case 2 aligned with the syringe 3.

The cap 11 is removed by pulling it in the distal direction D away from the case 2. As the cap 11 translates distally relative to the case 2, the bosses 11.2 on the cap 11 frictionally engage the protective needle sheath 5 and pull it off the needle 4 as the cap 11 is pulled in the distal direction D, and the compliant beam 11.3 disengages the aperture 7.6 in the needle shroud 7, as shown in FIG. 16. The compliant beam 11.3 translates distally within the aperture 7.6 until it is no longer abutted radially by the radial stop 2.15 and engages a proximal surface of the aperture 7.6 (which may be ramped) and deflects radially to disengage the aperture 7.6. The syringe 3 is fixed in position relative to the case 2, so pulling the cap 11 in the distal direction D does not cause any axial movement of the syringe 3. In an exemplary embodiment, the syringe 3 is also fixedly rotationally relative to the case 2 (e.g., by an interference fit with the case 2 and/or the needle shroud 7).

FIG. 17A is a longitudinal section of an exemplary embodiment of the autoinjector 1 according to the present invention prior to use. FIG. 17B is a schematic side view of an exemplary embodiment of the autoinjector 1 according to the present invention prior to use, wherein the case 2 is removed for clarity.

When the cap 11 is removed, the needle shroud 7 is in a first extended position FEP relative to the case 2, protruding from the case 2 in the distal direction D. The first extended position FEP is defined by the first plunger boss 10.1 abutting the shroud rib 7.7.

FIG. 18A is a longitudinal section of an exemplary embodiment of the autoinjector 1 according to the present invention during use. FIG. 18B is a schematic side view of an exemplary embodiment of the autoinjector 1 according to the present invention during use, wherein the case 2 is removed for clarity.

When the autoinjector 1 is pressed against an injection site, the needle shroud 7 translates proximally relative to the case 2 against the biasing force of the shroud spring 8 from the first extended position FEP to a retracted position RP, as shown in FIGS. 18A and 18B. FIG. 19 shows an exemplary embodiment of the plunger release mechanism 12 when the needle shroud 7 is in the retracted position RP. As the needle shroud 7 translates from the first extended position FEP to the retracted position RP, the needle shroud 7 translates distally causing the first plunger boss 10.1 to, starting from the position shown in FIG. 8, ride along the shroud rib 7.7 until it is distal of the shroud rib 7.7. When the first plunger boss 10.1 is distal of the shroud rib 7.7 and may be accommodated by the receiving element, the plunger 10 is no longer prevented from rotating in the second rotational direction R2 relative to the case 2. Thus, the force of the drive spring 9 on the plunger 10 and the engagement of the second plunger boss 10.2 on the second angled surface 2.11 in the case slot 2.3, causes the plunger 10 to rotate relative to the case 2. In an exemplary embodiment, the needle shroud 7 may include an aperture, a recess or a slot proximal of the shroud rib 7.7 to accommodate the first plunger boss 10.1 when the needle shroud 7 is in the retracted position RP and the plunger 10 rotates relative to the case 2.

In an exemplary embodiment, the shroud rib 7.7 (e.g., on the longitudinal face 7.10) may include a resistance feature (e.g., a projection, a ramp, a recess, etc.) adapted to abut the first plunger boss 10.1 as the needle shroud 7 translates from the first extended position FEP to the retracted position RP. When the first plunger boss 10.1 abuts the resistance feature, a tactile feedback is provided in the form of increased resistance to pressing the autoinjector 1 against the injection site. The tactile feedback may be used to indicate that needle 4 will be inserted into the injection site upon further depression of the autoinjector 1 against the injection site. Prior to the needle shroud 7 reaching the retracted position RP, if the autoinjector 1 is removed from the injection site, the needle shroud and reposition as the needle shroud 7 will re-extend to its initial position under the force of the shroud spring 8. When the needle shroud 7 is in the retracted position RP, the needle 4 has been inserted into the injection site. Those of skill in the art will understand that a penetration depth of the needle 4 may be varied by, for example, limiting retraction of the needle shroud 7 relative to the case 2, modifying an axial position of the syringe 3 relative to the case 2, modifying a length of the needle 4, etc. Thus, the autoinjector 1 of the present invention may be used for sub-cutaneous, intra-dermal and/or intra-muscular injection.

FIG. 20A is a longitudinal section of an exemplary embodiment of the autoinjector 1 according to the present invention during use. FIG. 20B is a schematic side view of an exemplary embodiment of the autoinjector 1 according to the present invention during use, wherein the case 2 is removed for clarity.

When the plunger 10 has rotated a sufficient distance in the second rotational direction R2 such that the second plunger boss 10.2 disengages the case slot 2.3, the plunger 10 is free to translate axially, under the force of the drive spring 9, relative to the case 2 to push the stopper 6 to deliver the medicament M from the syringe 3 through the needle 4.

In an exemplary embodiment, disengagement of the first plunger boss 10.1 from the shroud rib 7.7 and/or the second plunger boss 10.2 from the case slot 2.3 may provide an audible feedback indicating that delivery of the medicament M has started. A viewing window in the case 2 may allow for a visual feedback that the plunger 10 is advancing within the syringe 3 for assessing the progress of displacement of the medicament M.

FIG. 21A is a longitudinal section of an exemplary embodiment of the autoinjector 1 according to the present invention after use. FIG. 21B is a schematic side view of an exemplary embodiment of the autoinjector 1 according to the present invention after use, wherein the case 2 is removed for clarity.

When the autoinjector 1 is removed from the injection site, the needle shroud 7 translates distally relative to the case 2 from the retracted position RP to a second extended position SEP under the biasing force of the shroud spring 8. In the second extended position SEP, the needle shroud 7 extends beyond a distal tip of the needle 4 and locks in an axial position relative to the case 2.

The second extended position SEP prevents needle-stick injury and may also indicate that the autoinjector 1 has been used (because the needle shroud 7 cannot move proximally from the second extended position SEP). In an exemplary embodiment, in the second extended position SEP, the needle shroud 7 protrudes further, e.g. 2 mm, from the case 2 than in the first extended position FEP. The needle shroud 7 may include an indicia (e.g., a red ring, text, a graphic) on a portion which is visually accessible when the needle shroud 7 is in the second extended position SEP but not in the first extended position FEP. The indicia may indicate that the autoinjector 1 has been used.

FIG. 22 is a schematic view of an exemplary embodiment of the second shroud lock mechanism 15 according to the present invention. As the needle shroud 7 translates from the retracted position RP toward the second extended position SEP, the shroud beam 7.1 passes the stop 2.12 in the distal direction D and relaxes radially outwards which is possible as the cap 11 is no longer present. In the second extended position SEP, the needle shroud 7 cannot translate proximally relative to the case 2, because the shroud beam 7.1 abuts the stop 2.12. The needle shroud 7 is thus locked in the second extended position SEP. Extension of the needle shroud 7 distally beyond the second extended position SEP may be prevented by a shroud boss 7.2 on the needle shroud 7 that abuts a case boss 2.8 on the case 2 (see FIG. 1).

FIGS. 23A to 23E are schematic views of another exemplary embodiment of a plunger release mechanism 12 of the autoinjector 1 according to the present invention. The plunger release mechanism 12 is arranged for preventing release of the plunger 10 prior to retraction of the needle shroud 7 relative to the case 2 and for releasing the plunger 10 once the needle shroud 7 is sufficiently retracted. In an exemplary embodiment, the plunger release mechanism 12 comprises the plunger 10, the rear case 2.2, and the needle shroud 7. In this exemplary embodiment, the needle shroud 7 is limited to axial movement relative to the case 2, and the plunger 10 can translate axially and rotate relative to the case 2.

In the exemplary embodiment shown in FIGS. 23A-E, the plunger 10 comprises a first plunger boss 10.1 adapted to engage a shroud rib 7.7 on the needle shroud 7, a second plunger boss 10.2 adapted to engage a case slot 2.3 in the case 2, and a plunger rib 10.3 adapted to engage the shroud rib 7.7 on the needle shroud 7. In an exemplary embodiment, the shroud rib 7.7 is disposed in a plane substantially perpendicular to a longitudinal axis of the case 2. The shroud 7.7 comprises a proximal face 7.8 adapted to engage the plunger rib 10.3, and a distal face 7.9 adapted to engage the first plunger boss 10.1. In an exemplary embodiment, the case slot 2.3 comprises a first angled surface 2.9 adapted to apply a rotational force in a first rotational direction R1 to the second plunger boss 10.2, a wall 2.10 adapted to abut the second plunger boss 10.2 to limit rotation of the plunger 10 relative to the case 2 in the first rotational direction R1, and a transversal surface 2.16 disposed in a plane substantially perpendicular to a longitudinal axis of the case 2.

FIG. 23A is a schematic view of an exemplary embodiment of the plunger release mechanism 12 of the autoinjector 1 according to the present invention during assembly of the drive subassembly 1.2. During assembly of the drive subassembly 1.2, the plunger 10 with the drive spring 9 is inserted into the rear case 2.2. When the second plunger boss 10.2 is axially aligned with the case slot 2.3, the plunger 10 is rotated in the first rotational direction R1 until the second plunger boss 10.2 is moved into the case slot 2.3 until it abuts the wall 2.10. In this position, the first angled surface 2.9 prevents the second plunger boss 10.2 from moving in the second rotational direction R2, and thus prevents the plunger 10 from rotating relative to the case 2.

After a syringe 3 (with the protective needle sheath 5 disposed on the needle 4) is inserted into the control assembly 1.1, the drive subassembly 1.2 is coupled to the control subassembly 1.1. In an exemplary embodiment, a pair of resilient beams 2.13 (shown in FIG. 1B) on the rear case 2.2 is adapted to snap into recesses 2.14 (shown in FIG. 3) in the front case 2.1 to lock the drive subassembly 1.2 to the control subassembly 1.1. FIG. 23B shows the drive assembly 1.2 being coupled to the control subassembly 1.1, wherein the needle shroud 7 translates proximally (e.g., by use of an assembly jig) causing the shroud rib 7.7 to abut the plunger rib 10.3. As shown in FIG. 23C, as the needle shroud rib 7.7 pushes the plunger rib 10.3, the angle of the plunger rib 10.3 causes the plunger 10 to rotate relative to the case 2 in the second rotational direction R2, and the second plunger boss 10.2 rides along the first angled surface 2.9 onto the transversal surface 2.16.

As shown in FIG. 23D, when the needle shroud 7 is released (e.g., by removing the assembly jig), the needle shroud 7 translates in the distal direction D relative to the case 2 under the force of the shroud spring 8 until the shroud rib 7.7 abuts the first plunger boss 10.1. For example, the distal face 7.9 of the shroud rib 7.7 may abut the first plunger boss 10.1 and maintain the needle shroud 7 in an axial position relative to the case 2. The second plunger boss 10.2 is prevented from disengaging the case slot 2.3 as it abuts the transversal surface 2.16 in the distal direction D.

FIG. 23E shows an exemplary embodiment of the plunger release mechanism 12 when the needle shroud 7 is in the retracted position RP. As the needle shroud 7 translates from the first extended position FEP to the retracted position RP, the needle shroud 7 translates distally causing the shroud rib 7.7 to, starting from the position shown in FIG. 23D, ride along the plunger rib 10.3 thereby rotating the second plunger boss 10.2 in the second rotational direction R2 along the transversal surface 2.16 until the second plunger boss 10.2 disengages the case slot 2.3 thus releasing the plunger 10. Then, under the force of the drive spring 9, the plunger 10 translates axially relative to the case 2 to deliver the medicament M from the syringe 3. In this exemplary embodiment, a tactile feedback may be provided in the form of an increase in resistance when the needle shroud 7 abuts and pushes against the plunger rib 10.3. The tactile feedback may indicate that needle insertion will commence or medicament delivery will be initiated if the autoinjector 1 is pressed further against the injection site.

In an exemplary embodiment the transversal surface 2.16 could be replaced by or comprise a concave shape for preventing inadvertent release of the plunger 10.

In another exemplary embodiment, the plunger 10 may not have the first plunger boss 10.1, the plunger rib 10.3 may be disposed at different angle than as described above, and the case slot 2.3 may not be angled relative to a transverse axis of the case 2. In this exemplary embodiment, when the autoinjector 1 is assembled, the plunger 10 is maintained in axial position relative to the case 2, because the second plunger boss 10.2 engages the case slot 2.3. However, the case slot 2.3 may not impart any rotational force on the second plunger boss 10.2 (or, in another exemplary embodiment, the case slot 2.3 may be angled to impart a rotational force on the second plunger boss 10.2 in the first rotational direction R1 to ensure that the second plunger boss 10.2 does not disengage the case slot 2.3 inadvertently).

In an exemplary embodiment, a tamper strip (not shown) may be arranged between the cap 11 and the front case 2.1 when the control subassembly 1.1 is assembled. The tamper strip may be useful for quality assurance.

In an exemplary embodiment, a force required to press the needle shroud 7 may be approximately 2-12 N.

In an exemplary embodiment, the syringe 3 used in the autoinjector 1 may be a syringe capable of containing approximately 1 mL of the medicament M. In another exemplary embodiment, the syringe 3 used in the autoinjector 1 may be a syringe capable of containing approximately 2 mL of the medicament M.

The autoinjector 1 according to the present invention may have an increased shelf-life compared to conventional autoinjectors, because, for example, only the plunger 10 is subjected to the relatively high force of the drive spring 9.

The autoinjector 1 according to the present invention may be used as a platform as the drive spring 9 can be changed to alter a force applied to the plunger 10, e.g., for delivering medicaments with different viscosities drugs or reconstituted medicaments, or changing a time required to inject a dose of the medicament.

The term “drug” or “medicament”, as used herein, means a pharmaceutical formulation containing at least one pharmaceutically active compound, wherein in one embodiment the pharmaceutically active compound has a molecular weight up to 1500 Da and/or is a peptide, a proteine, a polysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or a fragment thereof, a hormone or an oligonucleotide, or a mixture of the above-mentioned pharmaceutically active compound, wherein in a further embodiment the pharmaceutically active compound is useful for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism, acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis, wherein in a further embodiment the pharmaceutically active compound comprises at least one peptide for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, wherein in a further embodiment the pharmaceutically active compound comprises at least one human insulin or a human insulin analogue or derivative, glucagon-like peptide (GLP-1) or an analogue or derivative thereof, or exendin-3 or exendin-4 or an analogue or derivative of exendin-3 or exendin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) human insulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N—(N-palmitoyl-Y-glutamyl)-des(B30) human insulin; B29-N—(N-lithocholyl-Y-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequence H-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser- Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following list of compounds:

• • H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
  • H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
  • des Pro36 Exendin-4(1-39),
  • des Pro36 [Asp28] Exendin-4(1-39),
  • des Pro36 [IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
  • des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or
  • des Pro36 [Asp28] Exendin-4(1-39),
  • des Pro36 [IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
  • des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
  • des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),
  • wherein the group -Lys6-NH2 may be bound to the C-terminus of the Exendin-4 derivative;
  • or an Exendin-4 derivative of the sequence
  • des Pro36 Exendin-4(1-39)-Lys6-NH2 (AVE0010),
  • H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,
  • des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,
  • H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,
  • H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,
  • des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
  • H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
  • des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,
  • des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,
  • H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
  • des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
  • H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25] Exendin-4(1-39)-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
  • des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
  • H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(S1-39)-(Lys)6-NH2,
  • H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2;
  • or a pharmaceutically acceptable salt or solvate of any one of the afore-mentioned Exendin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra low molecular weight heparin or a derivative thereof, or a sulphated, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and/or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium.

Antibodies are globular plasma proteins (˜150 kDa) that are also known as immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

The Ig monomer is a “Y”-shaped molecule that consists of four polypeptide chains; two identical heavy chains and two identical light chains connected by disulfide bonds between cysteine residues. Each heavy chain is about 440 amino acids long; each light chain is about 220 amino acids long. Heavy and light chains each contain intrachain disulfide bonds which stabilize their folding. Each chain is composed of structural domains called Ig domains. These domains contain about 70-110 amino acids and are classified into different categories (for example, variable or V, and constant or C) according to their size and function. They have a characteristic immunoglobulin fold in which two R sheets create a “sandwich” shape, held together by interactions between conserved cysteines and other charged amino acids.

There are five types of mammalian Ig heavy chain denoted by α, δ, ε, γ, and μ. The type of heavy chain present defines the isotype of antibody; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.

Distinct heavy chains differ in size and composition; α and γ contain approximately 450 amino acids and 6 approximately 500 amino acids, while μ and ε have approximately 550 amino acids. Each heavy chain has two regions, the constant region (CH) and the variable region (V_H). In one species, the constant region is essentially identical in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains γ, α and δ have a constant region composed of three tandem Ig domains, and a hinge region for added flexibility; heavy chains μ and ε have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 110 amino acids long and is composed of a single Ig domain.

In mammals, there are two types of immunoglobulin light chain denoted by λ and κ. A light chain has two successive domains: one constant domain (CL) and one variable domain (VL). The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two light chains that are always identical; only one type of light chain, κ or λ, is present per antibody in mammals.

Although the general structure of all antibodies is very similar, the unique property of a given antibody is determined by the variable (V) regions, as detailed above. More specifically, variable loops, three each the light (VL) and three on the heavy (VH) chain, are responsible for binding to the antigen, i.e. for its antigen specificity. These loops are referred to as the Complementarity Determining Regions (CDRs). Because CDRs from both VH and VL domains contribute to the antigen-binding site, it is the combination of the heavy and the light chains, and not either alone, that determines the final antigen specificity.

An “antibody fragment” contains at least one antigen binding fragment as defined above, and exhibits essentially the same function and specificity as the complete antibody of which the fragment is derived from. Limited proteolytic digestion with papain cleaves the Ig prototype into three fragments. Two identical amino terminal fragments, each containing one entire L chain and about half an H chain, are the antigen binding fragments (Fab). The third fragment, similar in size but containing the carboxyl terminal half of both heavy chains with their interchain disulfide bond, is the crystalizable fragment (Fc). The Fc contains carbohydrates, complement-binding, and FcR-binding sites. Limited pepsin digestion yields a single F(ab′)2 fragment containing both Fab pieces and the hinge region, including the H-H interchain disulfide bond. F(ab′)2 is divalent for antigen binding. The disulfide bond of F(ab′)2 may be cleaved in order to obtain Fab′. Moreover, the variable regions of the heavy and light chains can be fused together to form a single chain variable fragment (scFv).

Pharmaceutically acceptable salts are for example acid addition salts and basic salts. Acid addition salts are e.g. HCl or HBr salts. Basic salts are e.g. salts having a cation selected from alkali or alkaline, e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), wherein R1 to R4 independently of each other mean: hydrogen, an optionally substituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenyl group, an optionally substituted C6-C10-aryl group, or an optionally substituted C6-C10-heteroaryl group. Further examples of pharmaceutically acceptable salts are described in “Remington's Pharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia of Pharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

Those of skill in the art will understand that modifications (additions and/or removals) of various components of the apparatuses, methods and/or systems and embodiments described herein may be made without departing from the full scope and spirit of the present invention, which encompass such modifications and any and all equivalents thereof.

Claims

1. A needle shroud for an auto-injector, the needle shroud comprising: a cylindrical collar having a distal end, a proximal end, and an outer cylindrical surface extending from the distal end of the cylindrical collar to the proximal end of the cylindrical collar;an annular flange extending inward from the cylindrical collar at the distal end of the cylindrical collar, the annular flange having (i) a distal side defining a first contact region for engaging the needle shroud to an injection site, (ii) an inner surface defining a circular opening for exposing a needle of the auto-injector, and (iii) a proximal side defining a second contact region for receiving a biasing force from a spring of the auto-injector;a pair of first arms extending proximally from the proximal end of the cylindrical collar such that a distal-most end of each first arm is (i) located at the proximal end of the cylindrical collar and (ii) substantially flush with the outer cylindrical surface of the cylindrical collar, a proximal end of each first arm of the pair of first arms comprising an outward protrusion; anda pair of resilient arms extending proximally from the proximal end of the cylindrical collar such that a distal-most end of each resilient arm is at the proximal end of the cylindrical collar, each resilient arm of the pair of resilient arms having (i) a relaxed position in which a proximal end of the respective resilient arm is outwardly biased relative to the outer cylindrical surface of the cylindrical collar and configured to limit proximal movement of the needle shroud relative to a housing of the auto-injector and (ii) a deflected position in which the proximal end of the respective resilient arm is deflected inward relative to the relaxed position,wherein an axial length of the pair of first arms is longer than an axial length of the pair of resilient arms.

2. The needle shroud of claim 1, wherein when the pair of resilient arms are in the relaxed position the pair of resilient arms are configured to engage a part of the auto-injector to prevent proximal movement of the needle shroud relative to the part.

3. The needle shroud of claim 2, wherein the pair of resilient arms are configured to inwardly deflect from the relaxed position to the deflected position as the pair of resilient arms engage the part.

4. The needle shroud of claim 1, wherein the axial length of the pair of first arms is more than twice as long as the axial length of the pair of resilient arms.

5. The needle shroud of claim 4, wherein the axial length of the pair of first arms is more than three times as long as the axial length of the pair of resilient arms.

6. The needle shroud of claim 5, wherein the axial length of the pair of first arms is more than four times as long as the axial length of the pair of resilient arms.

7. The needle shroud of claim 1, wherein the pair of resilient arms are disposed between the pair of the first arms and in an opening defined by the pair of first arms.

8. The needle shroud of claim 1, wherein the pair of first arms extend along a first plane and the pair of resilient arms extend along a second plane that is perpendicular to the first plane.

9. The needle shroud of claim 8, wherein the pair of first arms are disposed symmetrically about the second plane, and the pair of resilient arms are disposed symmetrically about the first plane such that no portion of the needle shroud is proximal to the pair of resilient arms in the second plane.

10. The needle shroud of claim 1, wherein the pair of resilient arms have distal-most ends that are substantially flush with the outer cylindrical surface of the cylindrical collar.

11. The needle shroud of claim 1, wherein each first arm of the pair of first arms comprises a tapered section.

12. The needle shroud of claim 1, wherein a proximal-most end of each resilient arm extends in a direction that is substantially parallel to a longitudinal axis of the cylindrical collar.

13. The needle shroud of claim 1, wherein a projected width of each first arm decreases in a proximal direction, the projected width being measured on (i) a plane that bisects the pair of first arms and (ii) in a direction perpendicular to a longitudinal axis of the cylindrical collar.

14. The needle shroud of claim 13, wherein a diameter of the needle shroud varies along a length of the needle shroud due to the outwardly biased shape of each resilient arm.

15. The needle shroud of claim 1, wherein the cylindrical collar, the annular flange, the pair of first arms, and the pair of resilient arms define a monolithic structure.

16. A needle shroud for an auto-injector, the needle shroud comprising: a cylindrical collar having a distal end, a proximal end, a longitudinal axis, and an outer cylindrical surface extending along the longitudinal axis from the distal end of the cylindrical collar to the proximal end of the cylindrical collar;an annular flange extending inward from the cylindrical collar at the distal end of the cylindrical collar, the annular flange defining a circular opening having a diameter that is less than a diameter of an inner cylindrical surface of the cylindrical collar, the inner cylindrical surface of the cylindrical collar extending from a proximal side of the annular flange to the distal end of the cylindrical collar;a pair of first arms extending proximally from the proximal end of the cylindrical collar such that a distal end of an outer surface of each first arm is substantially flush with the outer cylindrical surface of the cylindrical collar; anda pair of resilient arms disposed in between the pair of first arms and extending proximally from the proximal end of the cylindrical collar, each resilient arm of the pair of resilient arms having (i) a relaxed position in which a proximal end of the respective resilient arm is outwardly biased relative to the outer cylindrical surface of the cylindrical collar and (ii) a deflected position in which the proximal end of the respective resilient arm is deflected inward relative to the relaxed position,wherein an axial length of the pair of first arms is longer than an axial length of the pair of resilient arms, and a length between the distal end of the cylindrical collar and the proximal end of the cylindrical collar is longer than the axial length of the pair of resilient arms.

17. The needle shroud of claim 16, wherein when the pair of resilient arms are in the relaxed position the pair of resilient arms are configured to engage a part of the auto-injector to prevent proximal movement of the needle shroud relative to the part.

18. The needle shroud of claim 17, wherein the pair of resilient arms are configured to inwardly deflect from the relaxed position to the deflected position as the pair of resilient arms engage the part, and a distal end of each resilient arm is substantially flush with the outer cylindrical surface of the cylindrical collar.

19. The needle shroud of claim 16, wherein each first arm comprises a tapered section arranged such that a projected width of each first arm decreases in a proximal direction, the projected width being measured on (i) a plane that bisects the pair of first arms and (ii) in a direction perpendicular to the longitudinal axis.

20. The needle shroud of claim 16, wherein a proximal-most end of each resilient arm extends in a direction that is substantially parallel to the longitudinal axis.

21. The needle shroud of claim 16, wherein when the pair of resilient arms are in the relaxed position a diameter of the needle shroud varies along a length of the needle shroud due to an outwardly biased shape of each resilient arm.

22. The needle shroud of claim 16, wherein a proximal end of each first arm comprises an outward protrusion.

23. A needle shroud comprising: a cylindrical portion having a distal end, a proximal end, a longitudinal axis, and an outer cylindrical surface extending along the longitudinal axis from the distal end of the cylindrical portion to the proximal end of the cylindrical portion;an annular flange extending inward from the distal end of the cylindrical portion and defining a circular opening;a pair of first arms extending proximally from the proximal end of the cylindrical portion such that a distal-most end of the pair of first arms is located at a first plane that is perpendicular to the longitudinal axis of the cylindrical portion; anda pair of first arms extending proximally from the proximal end of the cylindrical portion such that a distal-most end of the pair of first arms is located at a first plane that is perpendicular to the longitudinal axis of the cylindrical portion; anda pair of outwardly biased resilient arms extending proximally from the proximal end of the cylindrical portion such that a distal-most end of the pair of outwardly biased resilient arms is located substantially at the first plane, each outwardly biased resilient arm having (i) a relaxed position in which a proximal end of the respective outwardly biased resilient arm is radially outward of the outer cylindrical surface of the cylindrical portion and the respective outwardly biased resilient arm has an outwardly biased shape and (ii) a deflected position in which the proximal end of the respective outwardly biased resilient arm is inward of the relaxed position, wherein each outwardly biased resilient arm is configured to (i) resiliently deflect inward from the outwardly biased shape of the relaxed position to the deflected position, and (ii) after deflecting inward resume the outwardly biased shape of the relaxed position to prevent proximal movement of the needle shroud relative to a housing of an auto-injector,wherein an axial length of the pair of first arms is more than four times as long as an axial length of the pair of outwardly biased resilient arms.

24. The needle shroud of claim 23, wherein the pair of outwardly biased resilient arms are configured to inwardly deflect from the relaxed position to the deflected position as the pair of resilient arms engage a part of the auto-injector when the needle shroud is in disposed in the auto-injector.

25. The needle shroud of claim 24, wherein each outwardly biased resilient arm is located in an opening defined by the pair of first arms, the opening extending from the proximal end of the cylindrical portion to a proximal end of the needle shroud.

26. The needle shroud of claim 23, wherein each first arm comprises a tapered section arranged such that a projected width of each first arm decreases in a proximal direction.

27. The needle shroud of claim 23, wherein a proximal-most end of each resilient arm extends in a direction that is substantially parallel to the longitudinal axis of the cylindrical portion.

28. The needle shroud of claim 23, wherein the pair of first arms are arranged such that a second plane extends through the pair of first arms, the pair of outwardly biased resilient arms are arranged such that a third plane extends through the outwardly biased resilient arms, and the first plane, the second plane, and the third plane are substantially perpendicular to one another.

29. The needle shroud of claim 28, wherein the cylindrical portion, the annular flange, the pair of first arms, and the pair of outwardly biased resilient arms define a monolithic structure, and the distal-most end of the pair of first arms and the distal-most end of the pair of outwardly biased resilient arms are substantially flush with the outer cylindrical surface of the cylindrical portion.

30. The needle shroud of claim 23, wherein a length between the distal end of the cylindrical portion and the proximal end of the cylindrical portion is longer than the axial length of the pair of outwardly biased resilient arms, and the distal-most end of the pair of first arms and the distal-most end of the pair of outwardly biased resilient arms are located the same distance from the distal end of the cylindrical portion.