Patent Publication Number: US-2022211951-A1

Title: Autoinjector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/933,661, filed Jul. 20, 2020, which is a continuation of U.S. patent application Ser. No. 16/163,388, filed Oct. 17, 2018, now U.S. Pat. No. 10,758,682, which is a continuation of U.S. patent application Ser. No. 14/903,351, filed Jan. 7, 2016, now U.S. Pat. No. 10,137,255, which is a U.S. national stage application under 35 USC § 371 of International Application No. PCT/EP2014/064425, filed on Jul. 7, 2014, which claims priority to European Patent Application No. 13175662.9, filed on Jul. 9, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     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 having a rib, a needle shroud telescopically coupled to the case and movable between a first extended position, a retracted position and a locked second extended position, a carrier slidably arranged in the case, adapted to hold a medicament container, and movable from a first axial position to a second axial position relative to the case, and a collar rotatably and slidably disposed in the case and coupled to the needle shroud and the carrier. The collar abuts the rib when the needle shroud is in the first extended position and the carrier is in the first axial position, and the collar disengages the rib when the needle shroud is in the retracted position and the carrier is in the second axial position. 
     In an exemplary embodiment, the autoinjector further comprises a plunger slidably coupled to the carrier, and a drive spring biasing the plunger relative to the carrier. The carrier includes a compliant beam having a boss adapted to engage an opening in the plunger when the carrier is in the first axial position. The boss is adapted to engage the case when the carrier is in the second axial position. 
     In an exemplary embodiment, the collar includes a shroud boss adapted to engage a shroud slot in the needle shroud, a carrier boss adapted to engage a carrier slot in the carrier and a case boss adapted to engage the rib in the case. The shroud boss, the carrier boss and the case boss are disposed in approximately a same plane on the collar. 
     In an exemplary embodiment, the collar is in a first angular position relative to the case when the needle shroud is in the first extended position and the carrier is in the first axial position. The collar rotates to a second angular position relative to the case and translates proximally relative to the case when the needle shroud moves from the first extended position to the retracted position. The collar translates distally relative to the case when the needle shroud is in the retracted position and the carrier moves from the first axial position to the second axial position. The boss disengages the opening when the carrier is in the second axial position and wherein the plunger translates axially relative to the carrier under the force of the drive spring advancing the carrier from the second axial position to a third axial position relative to the case. The collar rotates to a third angular position relative to the case and translates with the needle shroud distally relative to the case when the carrier is in the third axial position. The collar rotates to a fourth angular position relative to the case when the needle shroud is in the locked second extended position. The shroud boss engages a shroud slot notch in the shroud slot and the carrier boss engages a carrier slot notch in the carrier slot when the collar is in the fourth angular position and the needle shroud is in the locked second extended position. The engagement of the carrier boss and the carrier slot notch substantially fixes the collar in an axial position relative to the case. 
     In an exemplary embodiment, the autoinjector further comprises a control spring biasing the collar relative to the case. 
     In an exemplary embodiment, the autoinjector further comprises a trigger button coupled to or integral with the carrier. 
     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 side view of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1B  is a side view of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1C  is a side view of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1D  is a side view of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIG. 1G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention prior to use, 
         FIGS. 2A to 2I  are schematic views of an exemplary embodiment of a control mechanism for an autoinjector according to the present invention, 
         FIG. 3A  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3B  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3C  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3D  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 3G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4A  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4B  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4C  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4D  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 4G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5A  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5B  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5C  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5D  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use larity, 
         FIG. 5E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 5G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6A  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6B  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6C  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6D  is a side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 6G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention during use, 
         FIG. 7A  is a side view of an exemplary embodiment of an autoinjector according to the present invention after use, 
         FIG. 7B  is a side view of an exemplary embodiment of an autoinjector according to the present invention after use, 
         FIG. 7C  is a side view of an exemplary embodiment of an autoinjector according to the present invention after use, 
         FIG. 7D  is a side view of an exemplary embodiment of an autoinjector according to the present invention after use, 
         FIG. 7E  is a semi-transparent side view of an exemplary embodiment of an autoinjector according to the present invention after use, 
         FIG. 7F  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention after use, and 
         FIG. 7G  is a longitudinal section of an exemplary embodiment of an autoinjector according to the present invention after use. 
     
    
    
     Corresponding parts are marked with the same reference symbols in all figures. 
     DETAILED DESCRIPTION 
       FIGS. 1A-1F and 1B  are different views of an exemplary embodiment of an autoinjector  1  according to the present invention prior to use. In an exemplary embodiment, the autoinjector  1  includes a case  2  telescopically coupled to a needle shroud  7 .  FIGS. 10 and 1D  are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 1E  is a related semi-transparent side view of the case  2 .  FIGS. 1F and 1G  are related longitudinal sections of the autoinjector  1 . 
     In an exemplary embodiment as shown in  FIGS. 1F and 1G , the case  2  is adapted to receive a medicament container, such as a syringe  3  containing a medicament M. The syringe  3  may be a pre-filled syringe and have a needle  4  arranged at a distal end. When the autoinjector  1  or the syringe  3  is assembled, a protective needle sheath  5  is removably attached to the needle  4 . A stopper  6  is arranged for sealing the syringe  3  proximally and for displacing the medicament M contained in the syringe  3  through the needle  4 . In other exemplary embodiments, the medicament container may be a cartridge or an ampoule, and the needle  4  may be removably coupled to the medicament container. In an exemplary embodiment, the syringe  3  is held in a syringe carrier  8  and supported at its proximal end therein. The syringe carrier  8  is slidably arranged within the case  2 . 
     In an exemplary embodiment, a cap (not illustrated) may be removably coupled to a distal end of the case  2 . The case  2  may include a viewing window  2 . 7  for providing visual access to contents of the syringe  3 . 
     In an exemplary embodiment, the needle shroud  7  is telescoped in the distal end of the case  2 . A control spring  9  is arranged to bias the needle shroud  7  in a distal direction D relative to the case  2 . 
     In an exemplary embodiment, a drive spring  10  (which may be a compression spring) is arranged within a proximal part  8 . 1  of the syringe carrier  8 . A plunger  12  serves for forwarding a force of the drive spring  10  to the stopper  6 . In an exemplary embodiment, the plunger  12  is hollow and telescoped within the proximal part  8 . 1  of the syringe carrier  8  wherein the drive spring  10  is arranged within the plunger  12  biasing the plunger  12  in the distal direction D relative to the syringe carrier  8 . In an exemplary embodiment, the proximal part  8 . 1  of the syringe carrier  8  protrudes through an opening in a proximal end of the case  2  and serves as a trigger button  13 . In other exemplary embodiments, a button overmold may be coupled to or integralled formed with the trigger button  13 . 
     In an exemplary embodiment, a plunger release mechanism  15  is arranged for preventing release of the plunger  12  prior to the needle  4  reaching an insertion depth and for releasing the plunger  12  once the needle  4  reaches its insertion depth. The plunger release mechanism  15  may comprise one or more compliant beams  8 . 3  with a respective first boss  8 . 4  arranged on the syringe carrier  8 , a respective first opening  12 . 1  (best seen in  FIG. 5F ) laterally arranged in the plunger  12  for engaging the first boss  8 . 4 , a proximal narrow section  2 . 4  of the case  2  adapted to radially outwardly support the first boss  8 . 4  and prevent it from disengaging the first opening  12 . 1 , a wide section  2 . 5  in the case  2  distal of the narrow section  2 . 4  adapted to allow radially outward deflection of the first boss  8 . 4  once the first boss  8 . 4  is axially aligned with the wide section  2 . 5 . At least one of the first boss  8 . 4  and the first opening  12 . 1  may be ramped such that the plunger  12  under load from the drive spring  10  deflects the first boss  8 . 4  radially outwards. 
     In an exemplary embodiment, a control mechanism  21  (best seen in  FIGS. 2A to 2I ) is arranged for selectively applying the force of the control spring  9  to the syringe carrier  8  or to the needle shroud  7 . Furthermore, the control mechanism  21  is arranged for locking the trigger button  13  such that it cannot be operated prior to depression of the needle shroud  7  against an injection site and for unlocking the trigger button  13  on depression of the needle shroud  7  against the injection site, thus allowing operation of the trigger button  13 . 
     In an exemplary embodiment, the control mechanism  21  comprises a collar  16  having a shroud boss  18  adapted to engage a shroud slot  17  in the needle shroud  7 , a carrier boss  20  adapted to engage a carrier slot  19  in the syringe carrier  8 , and a case boss  22  adapted to engage an angled case rib  2 . 9  on the case  2 . 
     In an exemplary embodiment, the control spring  9  is proximally grounded in the case  2  and distally bears against the collar  16  which is movable axially and rotationally relative to the case  2 . In the initial state prior to use, the control spring  9  may be compressed between the case  2  and the collar  16 . 
       FIGS. 2A to 2I  are schematic views of exemplary embodiments of the components of the control mechanism  21  corresponding to different states of operation of the autoinjector  1 . Although the case boss  22 , the carrier boss  20  and the shroud boss  18  are shown at different axial positions for clarity in  FIGS. 2A to 2I , in an exemplary embodiment, all of the bosses  18 ,  20 ,  22  on the collar  16  are disposed in the same plane as shown in  FIG. 1E . In an exemplary embodiment, the shroud slot  17  comprises a transversal first surface  17 . 1 , a transversal second surface  17 . 2 , a longitudinal third surface  17 . 3 , a transversal fourth surface  17 . 4 , an angled fifth surface  17 . 5 , a transversal sixth surface  17 . 6  and a transversal seventh surface  17 . 7 . In an exemplary embodiment, the carrier slot  19  comprises a transversal first surface  19 . 1 , an angled second surface  19 . 2 , an angled third surface  19 . 3 , a longitudinal fourth surface  19 . 4  and a transversal fifth surface  19 . 5 . 
     A exemplary sequence of operation of the autoinjector  1  is as follows: 
     Prior to use the autoinjector  1  is in the state as illustrated in  FIGS. 1A to 1G , and the control mechanism  21  is in the state illustrated in  FIG. 2A . If applicable, the autoinjector  1  is removed from a packaging. The medicament M in the syringe  3  may be visually examined through the viewing window  2 . 7 . 
     If the cap (not illustrated) is attached to the case  2  and/or the protective needle sheath  5 , the cap may be removed by pulling it in the distal direction D away from the case  2  thereby also removing the protective needle sheath  5  from the needle  4 . The load exerted by pulling the cap  11  is resolved in the case  2 , because the case boss  22  on the collar  16  abuts the angled case rib  2 . 9  in the distal direction D. The collar  16  is in a first angular position relative to the case  2 . As the case rib  2 . 9  is angled, a rotational force in a first rotational direction R 1  and an axial force in the distal direction Dare applied to the collar  16  due to the control spring  9  biasing the collar  16  in the distal direction D. The rotational and axial forces are resolved by the shroud boss  18  abutting the shroud slot  17  and/or the carrier boss  20  abutting the carrier slot  19  (in the illustrated embodiment both are used) such that the collar  16  cannot rotate or translate axially relative to the case  2 . The syringe carrier  8  is in a first axial position relative to the case  2 . 
     Movement of the syringe carrier  8  in the distal direction Dis prevented by the carrier boss  20  being in contact with the angled second surface  19 . 2  of the carrier slot  19 . 
     Thus, depression of the trigger button  13  is prevented. Movement of the syringe carrier  8  in the proximal direction P is prevented by a backstop (not illustrated) on the case  2 . Furthermore, the force of the control spring  9  on the collar  16  prevents the syringe carrier  8  from moving in the proximal direction P. 
     The needle shroud  7  is in a first extended position EP, protruding from the case  2  in the distal direction D. The extension of the needle shroud  7  distally beyond the case  2  is limited by the shroud boss  18  abutting the transversal first surface  17 . 1  and the transversal second surface  17 . 2  on the shroud slot  17 . Due to the collar  16  being prevented from moving in the distal direction D by the case rib  2 . 9 , the needle shroud  7  cannot move in the distal direction D either. Movement of the needle shroud  7  in the proximal direction P relative to the case  2  results in a corresponding axial translation of the collar  16  relative to the case  2 , compressing the control spring  9 . 
     The plunger release mechanism  15  prevents the plunger  12  from being released. 
     When the autoinjector  1  is pressed against an injection site, the needle shroud  7  is pressed into the case  2  into a retracted position RP against the force of the control spring  9 . 
       FIGS. 3A and 3B  are different views of an exemplary embodiment of the autoinjector  1  with the needle shroud  7  in the retracted position RP.  FIGS. 3C and 3D  are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 3E  is a related semi-transparent side view of the case  2  with the collar  16 .  FIGS. 3F and 3G  are related longitudinal sections of the autoinjector  1 .  FIG. 2B  shows the control mechanism  21  as the needle shroud  7  is translating from the extended position EP to the retracted position RP.  FIG. 2C  shows the control mechanism  21  when the needle shroud  7  is in the retracted position RP. 
     The force opposing depression of the needle shroud  7  is provided by the control spring  9  through the collar  16  and the shroud boss  18  engaging the transversal first surface  17 . 1 . During depression of the needle shroud  7  towards the retracted position RP, the shroud boss  18  abuts the transversal first surface  17 . 1  of the shroud slot  17  (cf.  FIG. 2B ) causing the collar  16  to translate axially in the proximal direction P relative to the case  2 . 
     The carrier boss  20  disengages the transversal first surface  19 . 1  of the carrier slot  19  in the proximal direction P. As the angled second surface  19 . 2  of the carrier slot  19  is angled relative to a transverse axis of the case  2 , a rotational force is applied to the collar  16  in a second rotational direction R 2  opposite the first rotational direction R 1 , causing the collar  16  to rotate to a second angular position relative to the case  2 . If the autoinjector  1  were removed from the injection site, the collar  16  and needle shroud  7  would return in the distal direction D into the positions shown in  FIGS. 1A to 1G  and the control mechanism  21  would return into the state shown in  FIG. 2A  due to the engagement of the case boss  22  to the angled case rib  2 . 9  applying the rotational force to the collar  16  in the first rotational direction R 1 . 
     When the needle shroud  7  is in the retracted position RP, the case boss  22  remains abutting the case rib  2 . 9  (cf.  FIG. 3E ) and the shroud boss  18  remains abutting the transversal first surface  17 . 1  of the shroud slot  17  (cf.  FIG. 3C ). Thus, the collar  16  is prevented from moving axially relative to the case  2 . 
       FIGS. 4A and 4B  are different side views of an exemplary embodiment of the autoinjector  1  after depression of the trigger button  13 .  FIGS. 4C and 4D  are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 4E  is a related semi-transparent side view of the case  2  with the collar  16 .  FIGS. 4F and 4G  are related longitudinal sections of the autoinjector  1 . 
     When the trigger button  13  is pressed, the syringe carrier  8  moves in the distal direction D from the first axial position to a second axial position relative to the case  2 , causing the carrier boss  20  to ride further along the angled second surface  19 . 2  and thereby rotating the collar  16  relative to the case  2  in the second rotational direction R 2  to a third angular position relative to the case  2 . After sufficient rotation of the collar  16  relative to the case  2 , the shroud boss  18  comes clear of the transversal first surface  17 . 1  of the shroud slot  17 , and the case boss  22  comes clear of the case rib  2 . 9 . As the collar  16  is thus axially neither supported by the case  2  nor by the shroud slot  17 , the collar  16  moves in the distal direction D guided by the shroud boss  18  along the longitudinal third surface  17 . 3  (cf.  FIG. 2D ), wherein the carrier boss  20  disengages the angled second surface  19 . 2  and moves in the distal direction D towards the angled third surface  19 . 3  of the carrier slot  19 . As the carrier boss  20  engages the angled third surface  19 . 3  of the carrier slot  19 , a rotational force in the second rotational direction R 2  is applied to the collar  16  which is resolved by the shroud boss  18  abutting the third longitudinal surface  17 . 3  such that the carrier boss  20  cannot disengage the angled third surface  19 . 3 . The collar  16  and the control spring  9  are thus axially coupled to the syringe carrier  8 . The control spring  9  coupled to the syringe carrier  8  through the collar  16  advances the syringe carrier  8  from the second axial position to a third axial position in the distal direction D relative to the case  2  such that the needle  4  is extended from the case  2  and inserted into the injection site. 
       FIGS. 5A and 5B  are different side views of an exemplary embodiment of the autoinjector  1  with the needle  4  extending from the case  2 .  FIGS. 5C  and  5 D are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 5E  is a related semi-transparent side view of the case  2  with the collar  16 .  FIGS. 5F and 5G  are related longitudinal sections of the autoinjector  1 . 
     The translation of the syringe carrier  8  relative to the case  2  is limited when the shroud boss  18  abuts the transversal fourth surface  17 . 4  of the shroud slot  17  (cf.  FIG. 2F ). The transversal fourth surface  17 . 4  thus defines a penetration depth of the needle  4 . 
     In an exemplary embodiment, prior to the shroud boss  18  abutting the transversal fourth surface  17 . 4  of the shroud slot  17 , the plunger  12  is released by the plunger release mechanism  15 . As the syringe carrier  8  translates in the distal direction D relative to the case  2 , the compliant beams  8 . 3  reach the wide section  2 . 5 , and the plunger  12 , under load from the drive spring  10 , deflects the first boss  8 . 4  on the compliant beam  8 . 3  radially outwards such that the first boss  8 . 4  disengages the first opening  12 . 1  in the plunger  12 . The plunger  12  is thus released and advanced by the drive spring  10  displacing the stopper  6  within the syringe  3  and ejecting the medicament M through the needle  4 . The release of the plunger release mechanism  15  may provide an audible and/or tactile feedback to the user. The progress of delivery of the medicament M can be observed through the viewing window  2 . 7  by examining the movement of the plunger  12  within the syringe  3 . The plunger  12  is visible in the viewing window  2 . 7  thus helping the user differentiate between a used and an un-used autoinjector  1 . 
     If the autoinjector  1  is removed from the injection site at any time after the needle  4  has reached insertion depth, the needle shroud  7  moves in the distal direction D driven by the control spring  9  which is coupled to the needle shroud  7  through the collar  16  and the shroud boss  18  abutting the transversal fourth surface  17 . 4  of the shroud slot  17 . 
       FIGS. 6A and 6B  are different side views of an exemplary embodiment of the autoinjector  1  with the syringe  3  emptied.  FIGS. 6C and 6D  are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 6E  is a related semi-transparent side view of the case  2  with the collar  16 .  FIGS. 6F and 6G  are related longitudinal sections of the autoinjector  1 . 
     When the syringe carrier  8  abuts a front stop (not illustrated) on the case  2 , the shroud boss  18  disengages the longitudinal third surface  17 . 3  and abuts the transversal fourth surface  14 . The force of the control spring  9  causes the collar  16  to translate axially and ride along the angled third surface  19 . 3 . Because the shroud boss  18  does not abut the longitudinal third surface, the collar  16  rotates relative to the case  2  in the second rotational direction R 2  to a fourth angular position relative to the case  2  due to the angled third surface  19 . 3 . After sufficient rotation of the collar  16  in the second rotational direction R 2 , the carrier boss  20  disengages the angled third surface  19 . 3 , and the shroud boss  18  moves from contact with the transversal fourth surface  17 . 4  to the angled fifth surface  17 . 5  (cf.  FIG. 2G ). After further rotation of the collar  16  in the second rotational direction R 2 , the carrier boss  20  abuts the longitudinal fourth surface  19 . 4 , preventing further rotation of the collar  16  in the second rotational direction R 2  but allowing for axial translation of the collar  16 . The shroud boss  18  applies an axial force on the angled fifth surface  17 . 5  to push the needle shroud  7  in the distal direction D relative to the case  2 . When the carrier boss  20  disengages the longitudinal fourth surface  19 . 4 , the force of the control spring  9  causes the collar  16  to rotate in the second rotational direction R 2 , because the shroud boss  18  abuts the angled fifth surface  17 . 5  of the shroud slot  17 . 
     The collar  16  rotates as the shroud boss  18  moves along the angled fifth surface  17 . 5  from the position shown in  FIG. 2H  until it abuts the transversal sixth surface  17 . 6 , and the rotation results in the carrier boss  20  engaging a notch adjacent a transversal fifth surface  19 . 5  in the carrier slot  19  (cf.  FIG. 2I ). At this point, the needle shroud  7  may abut a front stop (not illustrated) in the case  2 . The needle shroud  7  is now in a second extended position SEP extending further from the case  2  in the distal direction D than in the extended position EP thus hiding the extended needle  4 . If the needle shroud  7  is attempted to move proximally from the second extended position SEP, the collar  16  is substantially prevented from moving axially relative to the case  2 , which prevents the needle shroud  7  from moving proximally relative to the case  2  from the second extended position SEP. The syringe carrier  8  has locked in an axial position relative to the case  2  (see  FIG. 5F  in which the first boss  8 . 4  proximally abuts the narrow section  2 . 4  of the case  2 ), and the collar  16  is substantially axially locked relative to the syringe carrier  8  via the engagement of the carrier boss  20  in the notch. If the needle shroud  7  is depressed, the shroud boss  18  will abut the sixth transversal surface  17 . 6  and prevent the needle shroud  7  from retracting. Thus, the needle shroud  7  is prevented from being retracted and is locked in the second extended position SEP to cover the needle  4 . This action is activated as soon as the needle  4  reaches insertion depth, and hence the needle  4  will always be shrouded upon removal from the injection site. This reduces the risk of needle stick injury. 
       FIGS. 7A and 7B  are different side views of an exemplary embodiment of the autoinjector  1  removed from the injection site with the needle shroud  7  in the second extended position SEP.  FIGS. 7C and 7D  are related side views of the autoinjector  1  with the case  2  removed for clarity.  FIG. 7E  is a related semi-transparent side view of the case  2  with the collar  16 .  FIGS. 7F and 7G  are related longitudinal sections of the autoinjector  1 . 
     In an exemplary embodiment, the shroud boss  18  could be arranged on the needle shroud  7  and engaged in the shroud slot  17 , which would be arranged in the collar  16 . Likewise the carrier boss  20  could be arranged on the syringe carrier  8  and engaged in the carrier slot  19 , which would be arranged in the collar  16 . Likewise the angled case rib  2 . 9  could be arranged on the collar  16  and the case boss  22  on the case  2 . 
     In another exemplary embodiment, the control mechanism  21  could be adapted to be applied in an autoinjector  1  without the trigger button  13 , but which is activated based on depression of the needle shroud  7 . For example, the a modified control mechanism  21  could include, e.g. a steeper angle of the angled second surface  19 . 2  of the carrier slot  19 , a reduced length of the transversal first surface  17 . 1  of the shroud slot  17 , and/or a reduced length of the angled case rib  2 . 9 . 
     In an exemplary embodiment, the case  2  may comprise a front case and a rear case which are attached to form the case  2 , in order to facilitate assembly. 
     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 praline 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-(w-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(w-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 Pro37Exendin-4(1-39)-NH2,   H-(Lys)5-des Pro36, des Pro37Exendin-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,   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 13 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 a, o, £, y, 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; a and y contain approximately 450 amino acids and o approximately 500 amino acids, while p and £ have approximately 550 amino acids. Each heavy chain has two regions, the constant region (CH) and the variable region (VH)- 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 y, a and o have a constant region composed of three tandem Ig domains, and a hinge region for added flexibility; heavy chains μ and £ 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 ′A and K. 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, Kor ′A, 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 (Fe). The Fe 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&#39;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.