Patent Publication Number: US-2023158254-A1

Title: Injector Device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional application of U.S. patent application Ser. No. 16/768,246, filed May 29, 2020, which is the national stage entry of International Patent Application No. PCT/EP2018/083181, filed on Nov. 30, 2018, and claims priority to Application No. EP 17306675.4, filed on Dec. 1, 2017, the disclosures of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to an injector device for a medicament. 
     BACKGROUND 
     Cartridge injection devices, for example cartridge auto-injectors, typically have a sealed cartridge that contains a medicament and a needle that is initially separated from the cartridge. An initiation movement moves the cartridge and needle together so that the needle pierces the cartridge. A plunger can then be moved into the cartridge to dispense medicament through the needle for injection to a user. 
     SUMMARY 
     This disclosure relates to an injector device that comprises a housing, a cartridge having a reservoir for medicament, a needle unit comprising a needle, the needle unit being movably mounted to the housing and wherein prior to use of the injector device the reservoir is sealed from the needle, a needle sleeve that is slidably mounted to the housing such that the needle sleeve slides into the housing during use of the injector device, the needle sleeve being configured to engage the needle unit and push the needle unit into engagement with the cartridge such that the needle is moved into fluid communication with the reservoir, and a thread adapted to cause rotation of the needle unit as the needle unit is pushed into engagement with the cartridge. 
     The thread may be disposed between the needle unit and the housing and/or the cartridge. For example, the thread may be disposed between the needle unit and the housing, or between the needle unit and the cartridge. 
     The thread may be arranged to couple the needle unit to the cartridge and/or the housing after rotation of the needle unit. 
     In some embodiments, the housing comprises a cartridge mounting portion that surrounds at least a part of the cartridge, and wherein the thread is arranged between the needle unit and the cartridge mounting portion. 
     The cartridge mounting portion may comprise the thread and the needle unit may comprise a thread engaging member arranged to engage the thread. For example, the thread engaging member may be a protrusion that engages the thread on the cartridge mounting portion. 
     Alternatively, the cartridge mounting portion may comprise an external thread, and the needle unit may comprise an internal thread that engages the external thread. In other examples, the needle unit may comprise an external thread, and the cartridge mounting portion may comprise an internal thread that engages the external thread. 
     The cartridge mounting portion may further comprise a groove leading into the thread, and the groove may be arranged such that during movement of the needle unit the needle unit moves linearly before the thread rotates the needle unit. In this way, as the actuator pushes the needle unit the thread engaging member moves along the groove and then into the thread, so that the needle unit initially moves linearly and is then rotated. 
     The needle may comprise a needle axis, and the needle unit may be adapted to rotate about the needle axis. 
     In some embodiments, the needle sleeve covers the needle until the needle sleeve has pushed the needle unit into engagement with the cartridge. From this position, further movement of the needle sleeve exposes the needle for injecting a patient. The injection device may further include a spring arranged to urge needle sleeve into an extended position so that after use the needle sleeve slides out of the housing to cover the needle. 
     In some embodiments, the needle sleeve may be adapted to disengage from the needle unit after the needle unit has rotated such that the needle sleeve can move independently of the needle unit. In this way, an initial movement of the needle sleeve into the housing pushes the needle unit into engagement with the cartridge, and during this movement the needle is rotated so that the needle sleeve disengages from the needle unit and can continue to move into the housing independently of the needle unit. 
     Movement of the needle sleeve into the housing after the needle unit has been rotated may act to trigger release of the medicament. For example, the movement of the needle sleeve into the housing may cause a piston drive mechanism to drive a piston into the cartridge to expel medicament from the needle. In one example, the piston drive mechanism includes a spring, a plunger, and a catch that holds the spring and plunger in a pre-loaded state. Movement of the needle sleeve into the housing releases the catch so that the spring urges the plunger into the cartridge to dispense medicament. 
     The needle sleeve may comprise a flange that engages the needle unit, and the needle unit may comprise a recess arranged such that after the needle unit has been rotated the flange is aligned with the recess. In this way, the needle sleeve can move over the needle unit. 
     Alternatively, the needle sleeve may comprise a helical engaging member and the needle unit may comprise a protrusion that engages the helical engaging member, and the helical engaging member may be arranged such that rotation of the needle unit moves the protrusion out of engagement with the helical engaging member. In this way, the needle sleeve can move over the needle unit. 
     The needle sleeve may comprise a groove and the needle unit may comprise a protrusion arranged to be received in the groove such that the needle sleeve pushes the needle unit via the protrusion, and the groove may comprise a circumferential portion to permit rotation of the needle unit relative to the needle sleeve. In this way, the needle unit is able to rotate relative to the needle sleeve as it is pushed into the housing. 
     The groove may further comprise a movement portion arranged to permit the needle sleeve to slide into the housing after rotation of the needle unit. 
     The cartridge may contain a medicament in the reservoir. 
     According to another aspect, a method of using an injector device is disclosed. The injector device comprises a cartridge having a reservoir for medicament, a needle unit comprising a needle that is sealed from the reservoir prior to use of the injector device, and a slidably mounted needle sleeve. The method includes
         sliding the needle sleeve into the housing such that the needle sleeve engages the needle unit and pushes the needle unit into engagement with the cartridge such that the needle moves into fluid communication with the reservoir, and   rotating the needle unit relative to the cartridge as the needle unit is pushed into engagement with the cartridge.       

     The injector device includes a cartridge with a reservoir for medicament that is initially sealed from a needle, and a mechanism for moving the needle into fluid communication with the reservoir prior to use. 
     These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG.  1 A  is a schematic side view of an injector device that embodies the invention, and a removable cap; 
         FIG.  1 B  is a schematic side view of the injector device of  FIG.  1 A , with the cap removed from the housing; 
         FIG.  2    is a cross-sectional view of an injector device; 
         FIGS.  3 A to  3 C  are cross-sectional views of the needle-end of the injector device, showing stages of operation of the injector device; 
         FIGS.  4 A and  4 B  show the needle unit of an injector device; 
         FIG.  5    shows a partial cross-sectional view of the needle-end of an injector device; 
         FIGS.  6 A and  6 B  show an alternative needle sleeve for an injector device; 
         FIG.  7    shows an alternative needle sleeve for an injector device; and 
         FIG.  8    shows an alternative needle unit for an injector device. 
     
    
    
     DETAILED DESCRIPTION 
     A drug delivery device, as described herein, may be configured to inject a medicament into a patient. For example, delivery could be sub-cutaneous, intra-muscular, or intravenous. Such a device could be operated by a patient or care-giver, such as a nurse or physician, and can include various types of safety syringe, pen-injector, or auto-injector. The device can include a cartridge-based system that requires piercing a sealed ampule before use. Volumes of medicament delivered with these various devices can range from about 0.5 ml to about 2 ml. Yet another device can include a large volume device (“LVD”) or patch pump, configured to adhere to a patient&#39;s skin for a period of time (e.g., about 5, 15, 30, 60, or 120 minutes) to deliver a “large” volume of medicament (typically about 2 ml to about 10 ml). 
     In combination with a specific medicament, the presently described devices may also be customized in order to operate within required specifications. For example, the device may be customized to inject a medicament within a certain time period (e.g., about 3 to about 20 seconds for auto-injectors, and about 10 minutes to about 60 minutes for an LVD). Other specifications can include a low or minimal level of discomfort, or to certain conditions related to human factors, shelf-life, expiry, biocompatibility, environmental considerations, etc. Such variations can arise due to various factors, such as, for example, a drug ranging in viscosity from about 3 cP to about 50 cP. Consequently, a drug delivery device will often include a hollow needle ranging from about 25 to about 31 Gauge in size. Common sizes are 17 and 29 Gauge. 
     The delivery devices described herein can also include one or more automated functions. For example, one or more of combining the needle and cartridge, needle insertion, medicament injection, and needle retraction can be automated. Energy for one or more automation steps can be provided by one or more energy sources. Energy sources can include, for example, mechanical, pneumatic, chemical, or electrical energy. For example, mechanical energy sources can include springs, levers, elastomers, or other mechanical mechanisms to store or release energy. One or more energy sources can be combined into a single device. Devices can further include gears, valves, or other mechanisms to convert energy into movement of one or more components of a device. 
     The one or more automated functions of an auto-injector may each be activated via an activation mechanism. Such an activation mechanism can include an actuator, for example, one or more of a button, a lever, a needle sleeve, or other activation component. Activation of an automated function may be a one-step or multi-step process. That is, a user may need to activate one or more activation components in order to cause the automated function. For example, in a one-step process, a user may depress a needle sleeve against their body in order to cause injection of a medicament. Other devices may require a multi-step activation of an automated function. For example, a user may be required to depress a button and retract a needle shield in order to cause injection. 
     In addition, activation of one automated function may activate one or more subsequent automated functions, thereby forming an activation sequence. For example, activation of a first automated function may activate at least two of combining the needle and cartridge, needle insertion, medicament injection, and needle retraction. Some devices may also require a specific sequence of steps to cause the one or more automated functions to occur. Other devices may operate with a sequence of independent steps. 
     Some delivery devices can include one or more functions of a safety syringe, pen-injector, or auto-injector. For example, a delivery device could include a mechanical energy source configured to automatically inject a medicament (as typically found in an auto-injector) and a dose setting mechanism (as typically found in a pen-injector). 
     According to some embodiments of the present disclosure, an exemplary drug delivery device  10  is shown in  FIGS.  1 A and  1 B . The device  10 , as described above, is configured to inject a medicament into a patient&#39;s body. The device  10  includes a housing  11  which typically contains a cartridge that defines a reservoir containing the medicament to be injected, and the components required to facilitate one or more steps of the delivery process. 
     The device  10  can also include a cap  12  that can be detachably mounted to the the housing  11 . Typically, a user must remove the cap  12  from the housing  11  before the device  10  can be operated. 
     As shown, the housing  11  is substantially cylindrical and has a substantially constant diameter along the longitudinal axis A-A. The housing  11  has a distal region D and a proximal region P. The term “distal” refers to a location that is relatively closer to a site of injection, and the term “proximal” refers to a location that is relatively further away from the injection site. 
     The device  10  can also include a needle sleeve  19  coupled to the housing  11  to permit movement of the sleeve  19  relative to the housing  11 . For example, the sleeve  19  can move in a longitudinal direction parallel to longitudinal axis A-A. Specifically, movement of the sleeve  19  in a proximal direction can permit a needle  17  to extend from distal region D of the housing  11 . 
     Insertion of the needle  17  can occur via several mechanisms. For example, the needle  17  may be fixedly located relative to the housing  11  and initially be located within an extended needle sleeve  19 . Proximal movement of the sleeve  19  by placing a distal end of the sleeve  19  against a patient&#39;s body and moving the housing  11  in a distal direction will uncover the distal end of the needle  17 . Such relative movement allows the distal end of the needle  17  to extend into the patient&#39;s body. Such insertion is termed “manual” insertion as the needle  17  is manually inserted via the patient&#39;s manual movement of the housing  11  relative to the sleeve  19 . 
     Another form of insertion is “automated”, whereby the needle  17  moves relative to the housing  11 . Such insertion can be triggered by movement of the sleeve  19  or by another form of activation, such as, for example, a button  13 . As shown in  FIGS.  1 A and  1 B , the button  13  is located at a proximal end of the housing  11 . However, in other embodiments, the button  13  could be located on a side of the housing  11 . 
     Other manual or automated features can include drug injection or needle retraction, or both. Injection is the process by which a bung or piston  14  is moved from a proximal location to a more distal location within the reservoir of the cartridge  18  in order to force a medicament from the cartridge  18  through the needle  17 . In some embodiments, a drive spring (not shown) is under compression before the device  10  is activated. A proximal end of the drive spring can be fixed within proximal region P of the housing  11 , and a distal end of the drive spring can be configured to apply a compressive force to a proximal surface of the piston  14 . Following activation, at least part of the energy stored in the drive spring can be applied to the proximal surface of the piston  14 . This compressive force can act on the piston  14  to move it in a distal direction. Such distal movement acts to compress the liquid medicament within the cartridge  18 , forcing it out of the needle  17 . 
     Following injection, the needle  17  can be retracted within the sleeve  19  or the housing  11 . Retraction can occur when the sleeve  19  moves distally as a user removes the device  10  from a patient&#39;s body. This can occur as the needle  17  remains fixedly located relative to the housing  11 . Once a distal end of the sleeve  19  has moved past a distal end of the needle  17 , and the needle  17  is covered, the sleeve  19  can be locked. Such locking can include locking any proximal movement of the sleeve  19  relative to the housing  11 . 
     Another form of needle retraction can occur if the needle  17  is moved relative to the housing  11 . Such movement can occur if the cartridge  18  within the housing  11  is moved in a proximal direction relative to the housing  11 . This proximal movement can be achieved by using a retraction spring (not shown), located in distal region D. A compressed retraction spring, when activated, can supply sufficient force to the cartridge  18  to move it in a proximal direction. Following sufficient retraction, any relative movement between the needle  17  and the housing  11  can be locked with a locking mechanism. In addition, the button  13  or other components of the device  10  can be locked as required. 
       FIG.  2    illustrates an example injector device  20  having a housing  21 , a cartridge  22 , and a needle unit  23 . The injector device  20  further includes a piston  24 , a piston drive mechanism  25 , and a needle sleeve  26 . 
     The cartridge  22  defines a reservoir  28  that contains a medicament and is mounted within the housing  21 . A distal end D of the cartridge  22  is sealed by an end cap  29 . A cartridge mounting portion  30  of the housing  21  supports the cartridge  22 . As illustrated, a part of the cartridge mounting portion  30  is tubular and surrounds the distal end of the cartridge  22 . This tubular part of the cartridge mounting portion  30  has an external surface disposed within the housing  21 . 
     As shown in  FIG.  2   , in an initial condition the needle  31  of the needle unit  23  is spaced from the end cap  29  at the distal end of the cartridge  22  such that the reservoir  28  is sealed from the needle  31 . Before or during use of the injector device  20  the needle unit  23  is moved into engagement with the distal end of the cartridge  22  such that the needle  31  pierces the end cap  29  of the cartridge  22 . In this way, the needle  31  is placed in fluid communication with the reservoir  28  and medicament can be expelled from the reservoir  28  via the needle  31 , as explained further hereinafter. 
     In the initial condition, illustrated in  FIG.  2   , the piston  24  is disposed at a proximal end of the reservoir  28  in the cartridge  22 , and the piston drive mechanism  25  is disposed in the proximal end of the housing  21 . The piston drive mechanism  25  comprises a spring  32 , a plunger  33 , and a catch  34 . The spring  32  is arranged to urge the plunger  33  against the piston  24  and into the cartridge  22  to expel medicament from the reservoir  28  during use. In the initial condition before use, as illustrated, the spring  32  is held in a compressed state by a catch  34 . Specifically, the catch  34  holds the plunger  33 , which holds the spring  32  in a compressed state such that no force is applied to the piston  24 . In this state, the piston drive mechanism  25  is pre-loaded. 
     As explained further hereinafter, the injector device  20  is actuated by an actuator, in this example the needle sleeve  26  that is rotationally and slidably movable within the housing  21  and protrudes from the distal end of the housing  21 . In this way, during use, the needle sleeve  26  is placed against the user&#39;s skin and the injector device  20  is pushed towards the user&#39;s skin while holding the housing  21 , this moves the needle sleeve  26  in an axial proximal direction, into the housing  21 . 
     In other examples, the actuator may be a lever, or a button, or a drive mechanism, for example a motor, that moves the needle sleeve  26  in an axial direction into the housing  21 . 
     The needle sleeve  26  acts to release the catch  34  once the needle sleeve  26  has moved into the housing  21  in a proximal direction. Once the catch  34  is released, the spring  32  urges the plunger  33  against the piston  24  and into the reservoir  28 . 
     As illustrated in  FIG.  2   , the catch  34  may include a tubular element  35  that surrounds the plunger  33  and spring  32 . The tubular element  35  includes protrusions  36  that engage recesses  37  in the plunger  33 , such that in the position illustrated in  FIG.  2    the plunger  33  is prevented from moving in a distal direction by the protrusions  36  and the recesses  37 . 
     As the needle sleeve  26  is moved proximally into the housing  21 , an end of the needle sleeve  26  engages the tubular element  35 , causing the tubular element  35  to rotate about the axis A of the injector device  20 . This rotation causes the protrusions  36  to disengage from the recesses  37 , thereby releasing the plunger  33 , which then moves under the force of the spring  32  into the reservoir  28 . 
     In one example, the end of the needle sleeve  26  that engages the tubular element  35  may comprise a chamfer (i.e. angled edge) that engages a protrusion on the tubular element  35  to cause the rotation. In other examples, the tubular element  35  may comprise a chamfer (i.e. angled edge) that is engaged by a protrusion on the needle sleeve  26  to cause the rotation. 
     In other examples, the catch  34  may comprise arms that include the protrusions that engage the plunger  33 . In this case, the needle sleeve  26  might deflect the arms by lifting them to disengage the protrusions from the recesses, thereby releasing the plunger  33 . 
     A biasing member, for example a spring  42 , may be arranged to act between the housing  21  and the needle sleeve  26  to urge the needle sleeve  26  in a distal direction so that it protrudes from the distal end of the housing  21 . 
     Before or during use, the needle unit  23  is combined with the cartridge  22  before the catch  34  is released. As explained below, movement of the needle sleeve  26  in an axial proximal direction initially causes the needle unit  23  to engage the distal end of the cartridge  22 , and further movement of the needle sleeve  26  releases the catch  34  so that plunger  33  begins delivery of the medicament via the needle  31 . 
       FIGS.  3 A to  3 C  illustrate operation of the injector device  20 . In the initial state, shown in  FIG.  3 A , the needle sleeve  26  is in an extended state protruding from the distal end of the housing  21 . The spring  42  urges the needle sleeve  26  in a distal direction. As illustrated, the needle  31 , supported by the needle unit  23 , is spaced from the end cap  29  of the cartridge  22  so that the reservoir  28  is sealed from the needle  31 . The needle  31  is centrally located such that it is aligned with the axis A of the injector device  20 . A distal end of the needle  31  is adapted to pierce a user&#39;s skin, and a proximal end of the needle  31  is adapted to pierce the end cap  29  of the cartridge  22  when the needle unit  23  engages the cartridge  22 . 
     As illustrated, the needle unit  23  includes a needle body  38  that supports the needle  31  and defines a recess  39  facing proximally in the housing  21 . As illustrated, the needle sleeve  26  comprises an annular flange  40  that engages a distal end of the needle body  38 , and the proximal end of the needle body  38  engages the cartridge mounting portion  30  of the housing  21 . 
     Specifically, in this example the needle body  38  is threadingly engaged with the cartridge mounting portion  30 . The outer surface of the cartridge mounting portion  30  comprises an external thread, and the needle body  38  comprises an internal thread within the recess  39 . In the initial condition, the cartridge mounting portion  30  and needle body  38  are partially threadingly engaged at a start of the thread, such that the needle  31  is spaced from the end cap  29  of the cartridge  22 . 
     The needle sleeve  26  is mounted in the housing  21  such that it can slide in an axial direction, but cannot rotate. The needle unit  23  is mounted between the needle sleeve  26  and the housing  21  such that it can rotate about the longitudinal axis A of the injector device  20 , and can move in an axial direction. The cartridge  22  is mounted to the cartridge mounting portion  30  such that the position of the cartridge  22  is fixed within the housing  21  and cannot rotate. 
     In this way, during use of the injector device the distal end of the needle sleeve  26  is placed against a user&#39;s skin and pushed down. This causes the needle sleeve  26  to move in a proximal direction into the housing  21  as illustrated in  FIGS.  3 B and  3 C . 
       FIG.  3 B  shows an intermediate position of the needle sleeve  26  during use. As shown, movement of the needle sleeve  26  into the housing  21  has moved the needle unit  23  into engagement with the cartridge mounting portion  30 , and the needle  31  has pierced the end cap  29  of the cartridge  22 , placing the needle in fluid communication with the reservoir  28 . The annular flange  40  of the needle sleeve  26  has pushed the needle body  38 , so that the needle sleeve  26  and needle unit  23  have moved axially into the housing  21  such that needle unit  23  has engaged the cartridge  22 . 
     As explained above, the needle body  38  is threadingly engaged with the cartridge mounting portion  30 , and so during the axial movement between the position shown in  FIG.  3 A  and the position shown in  FIG.  3 B , the needle unit  23  rotates relative to the cartridge  22  and the housing  21 . In particular, the needle unit  23  has been rotated about the axis A of the injector device  20 , which is aligned to the needle  31 . 
     The thread engagement between the needle body  38  and the cartridge mounting portion  30  may have a high pitch thread, so that a lower force is required to move the needle unit  23  in an axial direction while rotating the needle unit  23 . In one example, the needle unit  23  is rotated through approximately 90 degrees during movement from the initial position ( FIG.  3 A ) to the intermediate position ( FIG.  3 B ). In other examples, the needle unit  23  is rotated between 30 degrees and 120 degrees. 
     In this example, the rotation of the needle unit  23  between the initial position ( FIG.  3 A ) and the intermediate position ( FIG.  3 B ) causes the needle sleeve  26  to disengage the needle body  38 . Specifically, referring to  FIGS.  4 A and  4 B , the needle body  38  is shaped such that after being rotated the needle sleeve  26  can pass over the needle body  38  in an axial direction. 
     As shown in  FIG.  4 B , the needle body  38  comprises recesses  41 . Similarly, the annular flange  40  of the needle sleeve  26  comprises segments and gaps between segments that correspond to the recesses  41  in the needle body  38 . In the initial position ( FIG.  3 A ) the segments of the annular flange  40  of the needle sleeve  26  are aligned with, and engage, the non-recessed parts  43  of the needle body  38  so that the needle sleeve  26  can push the needle unit  23  in an axial direction. Once the needle body  38  has been rotated (due to the thread engagement with the cartridge mounting portion  30  ( FIG.  3 B )) the segments of the annular flange  40  are aligned with the recesses  41  in the needle body  38 , allowing the needle sleeve  26  to pass over the needle body  38  in an axial direction, so that the needle sleeve  26  is able to move axially independently of the needle unit  23 . 
     Therefore, as illustrated in  FIG.  3 C , after the intermediate position the needle sleeve  26  continues to move in an axial direction, but the needle unit  23  does not. In this way, the needle  31  is exposed and can pierce the skin of the user. In the position of  FIG.  3 C , movement of the needle sleeve  26  has released the catch ( 34 , see  FIG.  2   ) of the piston drive mechanism ( 25 , see  FIG.  2   ), as previously described with reference to  FIG.  2   , and the piston ( 24 , see  FIG.  2   ) is urged into the cartridge  22  to deliver medicament via the needle  31 . 
     After use, when the injector device  20  is removed from the skin, the spring  42  urges the needle sleeve  26  back to its initial position so that the needle  31  is covered again. 
     In the position shown in  FIG.  3 B , the thread between the needle body  38  and the cartridge mounting portion  30  locks the needle unit  23  onto the cartridge mounting portion  30  of the housing  21 . 
     Additionally, locking members  44  may be provided to lock the needle unit  23  on the cartridge mounting portion  30  of the housing  21 . For example, the thread may include an indent  45  to receive a protrusion  44  of the needle body  38  in the position of  FIG.  3 B , to prevent the needle unit  23  from moving back in the distal direction. Additionally or alternatively, the housing, cartridge mounting portion, and/or the needle body may comprise one or more catches to lock the needle unit in the position illustrated in  FIG.  3 B  and  FIG.  3 C . 
     In the example described above, during use the needle unit  23  is initially rotated into engagement with the cartridge mounting portion  30 , and then decoupled from the needle sleeve  26  so that the needle sleeve  26  can continue moving axially to release the catch ( 34 , see  FIG.  2   ). However, in alternative examples, the needle unit  23  may be adapted to initially slide axially towards the cartridge  22  as the needle sleeve  26  pushes the needle unit  23 , and then the needle unit  23  is rotated to engage with the cartridge mounting portion  30  and disengage from the needle sleeve  26 . 
       FIG.  5    illustrates a further example of the engagement between the cartridge mounting portion  30  and the needle unit  23 . In this example, the cartridge mounting portion  30  comprises a notch  46 , a groove  47 , and a threaded section  48 . The needle body  38  comprises a protrusion  44  that engages the notch  46 , groove  47 , and threaded section  48  in turn as the needle unit  23  is moved axially towards the cartridge  22 .  FIG.  5    illustrates the initial position of the needle body  38  and needle sleeve  26 , equivalent to that shown in  FIG.  3 A . 
     During use, the needle sleeve  26  pushes the needle unit  23  in an axial direction, as previously described, and the protrusion  44  is urged out of the notch  46  and into the groove  47 , which permits the needle unit  23  to move axially without rotation until the protrusion  44  meets the threaded section  48 , which then causes the needle unit  23  to rotate. 
     During the axial and/or rotational movement the needle  31  has pierced the end cap  29  of the cartridge  22 , placing the needle  31  in fluid communication with the reservoir  28 . The rotation caused by the threaded section  48  allows the needle sleeve  26  to disengage from the needle body  23  as previously described, so that the needle sleeve  26  can continue its axial movement to release the catch ( 34 , see  FIG.  2   ) and trigger delivery of the medicament. The notch  46  helps to ensure that the spacing between the needle  31  and the cartridge  22  is maintained until a force is applied to the needle sleeve  26  at the beginning of use of the injector device  20 . 
       FIGS.  6 A and  6 B  illustrate a further example of the engagement between the needle sleeve  26  and the needle unit  23 . In this example, the needle sleeve  26  comprises a helical member  49  on its internal surface. The needle unit  23  includes a protrusion  50  on its outer surface that is engaged by the helical member  49  of the needle sleeve  26  during use. In this way, axial force applied to the needle sleeve  26  is transferred to the needle unit  23  via the helical member  49  and protrusion  50 , urging the needle unit  23  into engagement with the cartridge mounting portion  30 . The shape of the helical member  49  also aids rotation of the needle unit  23  as the needle sleeve  26  pushes against the protrusion  50 . As the needle unit  23  rotates due to the thread engagement between the needle unit  23  and the cartridge mounting portion  30 , the protrusion  50  moves out of engagement with the helical member  49  such that the needle sleeve  26  can continue its axial movement without the needle unit  23 . In particular, as illustrated in  FIG.  6 A , during axial movement of the needle sleeve  26  and needle unit  23  the protrusion  50  engages the helical member  49  at positon  50   a . Then, as the needle unit  23  rotates, the protrusion  50  moves to position  50   b , and then position  50   c  where the protrusion  50  is not in engagement with the helical member  49  and so the needle sleeve  26  can move further in an axial direction independently of the needle unit  23 . 
     In some examples, the needle sleeve  26  comprises a single helical member  49 , and the needle unit  23  comprises a single protrusion  50 . However, as illustrated in  FIG.  6 B , the needle sleeve  26  may comprise two helical members  49  and the needle body  38  correspondingly comprises two protrusions  50 . In other examples, the needle sleeve  26  may instead comprise three or more helical members  49 . 
       FIG.  6 B  also shows optional end stops  51  that the protrusions  50  engage once the desired amount of rotation has been reached, to prevent over-rotation. The end stops  51  are positioned such that the protrusions  50  can pass between the end of the helical member  49  and the end stop  51 . 
     In an alternative example similar to that illustrated in  FIGS.  6 A and  6 B , the needle unit  23  may comprise the one or more helical members  49 , and the needle sleeve  26  may comprise the corresponding protrusions  50 . 
       FIG.  7    shows an alternative example of the engagement between the needle sleeve  26  and the needle unit  23 . In this example, the needle sleeve  26  comprises an ‘L’ shaped slot  52 , and the needle unit  23  comprises a protrusion  53  that engages the ‘L’ shaped slot  52 . The ‘L’ shaped slot  52  is disposed in the circumferential wall of the needle sleeve  26 . As illustrated, the ‘L’ shaped slot  52  has a circumferential portion  54  extending in a circumferential direction about the needle sleeve  26 , and an axial portion  55  extending in an axial direction of the needle sleeve  26 . 
     In an initial position the protrusion  53  is in the location indicated by  53   a . In this position, the needle sleeve  26  and needle unit  23  move together in an axial direction as the needle sleeve  26  presses the needle unit  23  via the circumferential portion  54  of the ‘L’ shaped slot  52  and protrusion  53 . Then, as the needle unit  23  is screwed onto the thread of the cartridge mounting portion  30  the protrusion  53  moves to the position indicated by  53   b , and from there the needle sleeve  26  is free to move axially independently of the needle unit  23 , as the protrusion  53  moves along the axial portion  55  to the position indicated by  55   c . In this way, the rotation of the needle unit  23  causes the needle sleeve  26  to disengage from the needle unit  23  so that the needle sleeve  26  can move axially over the needle unit  23  to expose the needle  31  and release the catch ( 34 , see  FIG.  2   ). 
       FIG.  8    shows an alternative example needle unit  23 . In this example, the needle body  38  comprises an external thread  56  that is arranged to engage with an internal thread on a part of the cartridge mounting portion  30  of the housing  21 . This arrangement means that the needle body  38  has a smaller circumference, which reduces the torque required to rotate the needle unit  23  into threaded engagement with the cartridge mounting portion  30 . 
     It will be appreciated that, in various examples, the needle unit  23  may be rotatably coupled to the cartridge mounting portion  30  (as explained previously), to the cartridge  22 , or to another part of the injector device  20  that is fixed to the housing  21 . For example, the injector device  20  may not include a cartridge mounting portion  30  that extends over the end of the cartridge  22 , as illustrated in  FIG.  2   , and so instead the cartridge  22  may include a thread and the other features described previously. 
     In the examples described above, the needle sleeve  26  does not rotate as it moves axially into the housing  21 . To achieve this, the housing  21  and the needle sleeve  26  comprise a groove and a protrusion, for example a rail, that are engaged with each other to prevent rotation of the needle sleeve  26  relative to the housing  21 . 
     In various examples, elastic stops are disposed between the needle unit  23  and the cartridge  22  or the housing  21 , to help prevent overly forceful contact between the needle body  38  and the end cap  29  of the cartridge  22  that could cause damage to the end cap  29 . 
     The terms “drug” or “medicament” are used synonymously herein and describe a pharmaceutical formulation containing one or more active pharmaceutical ingredients or pharmaceutically acceptable salts or solvates thereof, and optionally a pharmaceutically acceptable carrier. An active pharmaceutical ingredient (“API”), in the broadest terms, is a chemical structure that has a biological effect on humans or animals. In pharmacology, a drug or medicament is used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well-being. A drug or medicament may be used for a limited duration, or on a regular basis for chronic disorders. 
     As described below, a drug or medicament can include at least one API, or combinations thereof, in various types of formulations, for the treatment of one or more diseases. Examples of API may include small molecules having a molecular weight of 500 Da or less; polypeptides, peptides and proteins (e.g., hormones, growth factors, antibodies, antibody fragments, and enzymes); carbohydrates and polysaccharides; and nucleic acids, double or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), ribozymes, genes, and oligonucleotides. Nucleic acids may be incorporated into molecular delivery systems such as vectors, plasmids, or liposomes. Mixtures of one or more drugs are also contemplated. 
     The drug or medicament may be contained in a primary package or “drug container” adapted for use with a drug delivery device. The drug container may be, e.g., a cartridge, syringe, reservoir, or other solid or flexible vessel configured to provide a suitable chamber for storage (e.g., short- or long-term storage) of one or more drugs. For example, in some instances, the chamber may be designed to store a drug for at least one day (e.g.,  1  to at least 30 days). In some instances, the chamber may be designed to store a drug for about 1 month to about 2 years. Storage may occur at room temperature (e.g., about 20° C.), or refrigerated temperatures (e.g., from about −4° C. to about 4° C.). In some instances, the drug container may be or may include a dual-chamber cartridge configured to store two or more components of the pharmaceutical formulation to-be-administered (e.g., an API and a diluent, or two different drugs) separately, one in each chamber. In such instances, the two chambers of the dual-chamber cartridge may be configured to allow mixing between the two or more components prior to and/or during dispensing into the human or animal body. For example, the two chambers may be configured such that they are in fluid communication with each other (e.g., by way of a conduit between the two chambers) and allow mixing of the two components when desired by a user prior to dispensing. Alternatively or in addition, the two chambers may be configured to allow mixing as the components are being dispensed into the human or animal body. 
     The drugs or medicaments contained in the drug delivery devices as described herein can be used for the treatment and/or prophylaxis of many different types of medical disorders. Examples of disorders include, e.g., diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism. Further examples of disorders are acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis. Examples of APIs and drugs are those as described in handbooks such as Rote Liste 2014, for example, without limitation, main groups 12 (anti-diabetic drugs) or 86 (oncology drugs), and Merck Index, 15th edition. 
     Examples of APIs for the treatment and/or prophylaxis of type 1 or type 2 diabetes mellitus or complications associated with type 1 or type 2 diabetes mellitus include an insulin, e.g., human insulin, or a human insulin analogue or derivative, a glucagon-like peptide (GLP-1), GLP-1 analogues or GLP-1 receptor agonists, or an analogue or derivative thereof, a dipeptidyl peptidase-4 (DPP4) inhibitor, or a pharmaceutically acceptable salt or solvate thereof, or any mixture thereof. As used herein, the terms “analogue” and “derivative” refers to a polypeptide which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, by deleting and/or exchanging at least one amino acid residue occurring in the naturally occurring peptide and/or by adding at least one amino acid residue. The added and/or exchanged amino acid residue can either be codable amino acid residues or other naturally occurring residues or purely synthetic amino acid residues. Insulin analogues are also referred to as “insulin receptor ligands”. In particular, the term, derivative” refers to a polypeptide which has a molecular structure which formally can be derived from the structure of a naturally occurring peptide, for example that of human insulin, in which one or more organic substituent (e.g. a fatty acid) is bound to one or more of the amino acids. Optionally, one or more amino acids occurring in the naturally occurring peptide may have been deleted and/or replaced by other amino acids, including non-codeable amino acids, or amino acids, including non-codeable, have been added to the naturally occurring peptide. Examples of insulin analogues are Gly(A21), Arg(B31), Arg(B32) human insulin (insulin glargine); Lys(B3), Glu(B29) human insulin (insulin glulisine); Lys(B28), Pro(B29) human insulin (insulin lispro); Asp(B28) human insulin (insulin aspart); 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. 
     Examples of insulin derivatives are, for example, B29-N-myristoyl-des(B30) human insulin, Lys(B29) (N-tetradecanoyl)-des(B30) human insulin (insulin detemir, Levemir®); 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-gamma-glutamyl)-des(B30) human insulin, B29-N-omega-carboxypentadecanoyl-gamma-L-glutamyl-des(B30) human insulin (insulin degludec, Tresiba®); B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyheptadecanoyl) human insulin. 
     Examples of GLP-1, GLP-1 analogues and GLP-1 receptor agonists are, for example, Lixisenatide (Lyxumia®), Exenatide (Exendin-4, Byetta®, Bydureon®, a 39 amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide (Victoza®), Semaglutide, Taspoglutide, Albiglutide (Syncria®), Dulaglutide (Trulicity®), rExendin-4, CJC-1134-PC, PB-1023, TTP-054, Langlenatide/HM-11260C, CM-3, GLP-1 Eligen, ORMD-0901, NN-9924, NN-9926, NN-9927, Nodexen, Viador-GLP-1, CVX-096, ZYOG-1, ZYD-1, GSK-2374697, DA-3091, MAR-701, MAR709, ZP-2929, ZP-3022, TT-401, BHM-034. MOD-6030, CAM-2036, DA-15864, ARI-2651, ARI-2255, Exenatide-XTEN and Glucagon-Xten. An examples of an oligonucleotide is, for example: mipomersen sodium (Kynamro®), a cholesterol-reducing antisense therapeutic for the treatment of familial hypercholesterolemia. Examples of DPP4 inhibitors are Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine. Examples of hormones include hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, and Goserelin. 
     Examples of polysaccharides include 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 polysaccharide, 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. An example of a hyaluronic acid derivative is Hylan G-F 20 (Synvisc®), a sodium hyaluronate. 
     The term “antibody”, as used herein, refers to an immunoglobulin molecule or an antigen-binding portion thereof. Examples of antigen-binding portions of immunoglobulin molecules include F(ab) and F(ab′)2 fragments, which retain the ability to bind antigen. The antibody can be polyclonal, monoclonal, recombinant, chimeric, de-immunized or humanized, fully human, non-human, (e.g., murine), or single chain antibody. In some embodiments, the antibody has effector function and can fix complement. In some embodiments, the antibody has reduced or no ability to bind an Fc receptor. For example, the antibody can be an isotype or subtype, an antibody fragment or mutant, which does not support binding to an Fc receptor, e.g., it has a mutagenized or deleted Fc receptor binding region. The term antibody also includes an antigen-binding molecule based on tetravalent bispecific tandem immunoglobulins (TBTI) and/or a dual variable region antibody-like binding protein having cross-over binding region orientation (CODV). 
     The terms “fragment” or “antibody fragment” refer to a polypeptide derived from an antibody polypeptide molecule (e.g., an antibody heavy and/or light chain polypeptide) that does not comprise a full-length antibody polypeptide, but that still comprises at least a portion of a full-length antibody polypeptide that is capable of binding to an antigen. Antibody fragments can comprise a cleaved portion of a full length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments that are useful in the present invention include, for example, Fab fragments, F(ab′)2 fragments, scFv (single-chain Fv) fragments, linear antibodies, monospecific or multispecific antibody fragments such as bispecific, trispecific, tetraspecific and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies), monovalent or multivalent antibody fragments such as bivalent, trivalent, tetravalent and multivalent antibodies, minibodies, chelating recombinant antibodies, tribodies or bibodies, intrabodies, nanobodies, small modular immunopharmaceuticals (SMIP), binding-domain immunoglobulin fusion proteins, camelized antibodies, and VHH containing antibodies. Additional examples of antigen-binding antibody fragments are known in the art. 
     The terms “Complementarity-determining region” or “CDR” refer to short polypeptide sequences within the variable region of both heavy and light chain polypeptides that are primarily responsible for mediating specific antigen recognition. The term “framework region” refers to amino acid sequences within the variable region of both heavy and light chain polypeptides that are not CDR sequences, and are primarily responsible for maintaining correct positioning of the CDR sequences to permit antigen binding. Although the framework regions themselves typically do not directly participate in antigen binding, as is known in the art, certain residues within the framework regions of certain antibodies can directly participate in antigen binding or can affect the ability of one or more amino acids in CDRs to interact with antigen. Examples of antibodies are anti PCSK-9 mAb (e.g., Alirocumab), anti IL-6 mAb (e.g., Sarilumab), and anti IL-4 mAb (e.g., Dupilumab). 
     Pharmaceutically acceptable salts of any API described herein are also contemplated for use in a drug or medicament in a drug delivery device. Pharmaceutically acceptable salts are for example acid addition salts and basic salts. 
     Those of skill in the art will understand that modifications (additions and/or removals) of various components of the APIs, formulations, apparatuses, methods, 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.