Patent Publication Number: US-2020289755-A1

Title: Injector Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is the national stage entry of International Patent Application No. PCT/EP2018/079548, filed on Oct. 29, 2018, and claims priority to Application No. EP 17306487.4, filed on Oct. 30, 2017, the disclosures of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to an injector device for a medicament. 
     BACKGROUND 
     Injection devices, for example auto-injectors, typically have a sealed container of medicament, and a needle for injection of the medicament into a patient. In one type of device, the medicament container may include a medicament cartridge and the needle may be initially separated from the cartridge. An initial action moves the cartridge and needle together so that the needle pierces the cartridge. In another type of device, the medicament container may include a syringe containing a medicament and the needle may be secured to the syringe. In both cases, a plunger or piston within the cartridge or syringe can be moved into the cartridge or syringe to dispense medicament through the needle for injection to a patient. 
     SUMMARY 
     In one aspect, an injector device includes an elongate housing having a proximal end and a distal end, and configured to receive container of medicament, a needle sleeve mounted within the housing and moveable between an extended position in which the needle sleeve at least partially extends from the distal end of the housing, and a retracted position in which the needle sleeve is received further within the housing than in the extended position, a piston rod moveable longitudinally within the housing, a piston spring configured to bias the piston rod towards a distal end of the housing to engage a container of medicament when received within the housing, and a release mechanism configured to control actuation of the piston rod, the release mechanism including a rotatable member disposed within the housing and in cooperating engagement with the needle sleeve such that movement of the needle sleeve from the extended position to the retracted position causes the rotatable member to rotate within the housing from a first position to a second position, at least one of the rotatable member and the needle sleeve including a helical guide track, the other of the rotatable member and the needle sleeve including a track follower in engagement with the helical guide track to rotate the rotatable member; wherein the rotatable member is in cooperating engagement with the piston rod by a guide track formed on one of the rotatable member and the piston rod, and a projection formed on the other of the rotatable member and the piston rod, the projection being received within the guide track, and the guide track being configured such that in the first position of the rotatable member, the piston rod is prevented from movement under the force of the piston spring, and in the second position of the rotatable member, the piston rod is free to move longitudinally within the housing under the force of the piston spring. 
     The rotatable member may have a first section of a first diameter and a second section of a second diameter, the longitudinal movement of the piston rod being from the second section towards the first section. 
     When the needle sleeve is in the extended position the rotatable member can be in the first position, when the needle sleeve has moved to the retracted position the rotatable member can be in the second position. The rotation of the rotatable member may be exclusively actuated by movement of the needle sleeve. 
     The guide track may include a first portion in which the projection is received when the rotatable member is in the first rotational position, and a second portion in which the projection is received when the rotatable member is in the second rotational position and when the piston rod moves longitudinally within the housing under the force of the piston spring. This may advantageously help provide two guide track portions which define locked and release positions of the release mechanism. 
     The first portion of the guide track may extend in a substantially circumferential direction of the rotatable member, and the second portion of the guide track extends in a substantially longitudinal direction of the rotatable member. This may advantageously help provide a locked position of the release mechanism until the rotatable member reaches a position for release of the piston rod. 
     The first portion of the guide track may extend in a helical path towards the second portion of the guide track. This may advantageously help reduce the force needed to rotate the rotatable member from the first to the second position of the rotatable member. 
     The first portion of the guide track may extend in a substantially perpendicular direction to the second portion of the guide track. This may advantageously help provide a secure locking position of the release mechanism against accidental activation under force of the piston spring. 
     The rotatable member may include a hollow cylindrical component and the piston rod may be disposed within the rotatable member, and the guide track may be formed on an inner surface of the rotatable member, and the projection may be formed on an outer surface of the piston rod. This may advantageously help provide a compact and space-efficient configuration of release mechanism. 
     The guide track may be a recessed groove in the rotatable member. This may advantageously help provide a compact rotatable member with reduced diameter. The guide track may alternatively be defined between spaced walls projecting from a surface of the rotatable member. This may advantageously help provide an alternative configuration of guide track without the need to machine or mould a groove, or may allow formation of a guide track on a rotatable member after manufacture of the rotatable member. Different configurations of guide track may thereby be produced. 
     The guide track may include a channel extending through a side wall of the rotatable member. This may advantageously help provide a reduced mass of rotatable member, for a lighter injector device. This may also, or alternatively advantageously help provide a simpler manufacturing process for the rotatable member as machining accuracy and tolerance of producing a groove of a constant depth around a circular body is not required. 
     The release mechanism may include a plurality of guide tracks formed on one of the rotatable member and the piston rod, and a plurality of projections formed on the other of the rotatable member and the piston rod and respectively received within the guide tracks. This may advantageously help provide a stable and even movement of the release mechanism and rotatable member. 
     The cooperating engagement between the needle sleeve and the rotatable member may include a second guide track formed on one of the rotatable member and the needle sleeve and a second projection formed on the other of the rotatable member and the needle sleeve, the second projection being received within the second guide track, and the guide track being configured in a helical path such that movement of the needle sleeve from the extended position to the retracted position causes the rotatable member to rotate within the housing from a first position to a second position. This may advantageously help provide a compact and space-efficient release mechanism, and allow smooth movement of the rotatable member, and control of the rotational angle relative to the movement of the needle sleeve. 
     There may be provided a plurality of second guide tracks formed on one of the rotatable member and the needle sleeve, and a plurality of second projections formed on the other of the rotatable member and the needle sleeve and respectively received within the second guide tracks. This may advantageously help provide a stable and even movement of the release mechanism and rotatable member. 
     The injector device may further include a needle unit at the distal end of the housing and including an injection needle held in a needle holder. The needle unit may include a needle retained within a holder. The needle unit may be fixedly secured within the housing, or maybe moveable within the housing. This may advantageously help provide a compact device of simple construction and ease of assembly. It may also advantageously help provide a device in which a needle can be pre-provided, and a medicament container later provided in a separate manufacturing or assembly step. 
     The rotatable member may rotate through around 90 degrees between the first position and the second position. This may advantageously help provide sufficient movement to provide distinct release and locking positions, but also not excessive rotation to be required to activate the release mechanism. 
     The injector device may further include a container of medicament received within the housing between the piston rod and the distal end of the injector device. The medicament container may include a cartridge of medicament, or may include a pre-filled syringe of medicament. The container of medicament may be moveable within the housing, or may be fixedly secured within the housing. 
     Also provided is a method of operating an injector device, the device including an elongate housing having a proximal end and a distal end and configured to receive a container of medicament, a needle sleeve mounted within the housing and moveable between an extended position in which the needle sleeve at least partially extends from the distal end of the housing, and a retracted position in which the needle sleeve is received further within the housing than in the extended position, a piston rod moveable longitudinally within the housing, a piston spring configured to bias the piston rod towards a distal end of the housing to engage a container of medicament when received within the housing, and a release mechanism configured to control actuation of the piston rod, the release mechanism including a rotatable member disposed within the housing and in cooperating engagement with the needle sleeve, and the rotatable member is in cooperating engagement with the piston rod by a guide track formed on one of the rotatable member and the piston rod, and a projection formed on the other of the rotatable member and the piston rod, the projection being received within the guide track, the method including moving the needle sleeve from the extended position to the retracted position and thereby causing the rotatable member to rotate within the housing from a first position in which the piston rod is prevented from movement under the force of the piston spring to a second position in which the piston rod is free to move longitudinally within the housing under the force of the piston spring. 
     These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Embodiments will now be described, by way of example, with reference to the accompanying drawings. 
         FIG. 1A  is a schematic side view of an injector device and a removable cap. 
         FIG. 1B  is a schematic side view of the injector device of  FIG. 1A , with the cap removed from the housing. 
         FIG. 2  is a side cross-sectional view of an injector device of a first embodiment. 
         FIG. 3  is an enlarged cross-sectional view of a proximal end of the injector device of  FIG. 2  illustrating the release mechanism in a starting position. 
         FIG. 4  is an enlarged cross-sectional view of the proximal end of the injector device of  FIG. 2  illustrating the release mechanism in the starting position but taken with the injector device rotated through 90 degrees about its longitudinal axis from the position shown in  FIG. 3 . 
         FIG. 5  is a side partial cross-sectional view of a rotator of the release mechanism of the injector device shown in  FIGS. 2 to 4 . 
         FIG. 6  is an enlarged cross-sectional view of the proximal end of the injector device of  FIG. 2  and taken along the same section as  FIG. 3  but illustrating the release mechanism during an injection process. 
         FIG. 7  is an enlarged cross-sectional view of the proximal end of the injector device of  FIG. 2  illustrating the release mechanism during an injection process but taken with the injector device rotated through 90 degrees about its longitudinal axis from the position shown in  FIG. 6 .  FIG. 8  is a side cross-sectional view of an injector device of a second embodiment, which includes a release mechanism as in the first embodiment, but wherein the injector device is configured to receive a pre-filled syringe. 
     
    
    
     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 device, including an 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 3 ml. 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). Yet another device may include a pre-filled syringe within a housing of the device. The syringe may be fixed within the housing or may be moveable within the housing, for example from a retracted position to an operation extended position. 
     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. 1A and 1B . Device  10 , as described above, is configured to inject a medicament into a patient&#39;s body. Device  10  includes a housing  11  which typically contains a cartridge or pre-filled syringe 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 housing  11 . Typically, a user must remove cap  12  from housing  11  before device  10  can be operated. 
     As shown, 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. 
     Device  10  can also include a needle sleeve  19  coupled to housing  11  to permit movement of sleeve  19  relative to housing  11 . For example, sleeve  19  can move in a longitudinal direction parallel to longitudinal axis A-A. Specifically, movement of sleeve  19  in a proximal direction can permit a needle  17  to extend from distal region D of housing  11 . 
     Insertion of needle  17  can occur via several mechanisms. For example, needle  17  may be fixedly located relative to housing  11  and initially be located within an extended needle sleeve  19 . Proximal movement of sleeve  19  by placing a distal end of sleeve  19  against a patient&#39;s body and moving housing  11  in a distal direction will uncover the distal end of needle  17 . Such relative movement allows the distal end of needle  17  to extend into the patient&#39;s body. Such insertion is termed “manual” insertion as needle  17  is manually inserted via the patient&#39;s manual movement of housing  11  relative to sleeve  19 . 
     Another form of insertion is “automated”, whereby needle  17  moves relative to housing  11 . Such insertion can be triggered by movement of sleeve  19 . In other types of device, another form of activation may be provided, such as, for example, a button  13 . As shown in  FIGS. 1A and 1B , button  13  is located at a proximal end of housing  11 . However, in other embodiments, button  13  could be located on a side of 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 needle  17 . In some embodiments, a drive spring (not shown) is under compression before device  10  is activated. A proximal end of the drive spring can be fixed within proximal region P of housing  11 , and a distal end of the drive spring can be configured to apply a compressive force to a proximal surface of piston  14 . Following activation, at least part of the energy stored in the drive spring can be applied to the proximal surface of piston  14 . This compressive force can act on 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 needle  17 . 
     Following injection, needle  17  can be retracted within sleeve  19  or housing  11 . Retraction can occur when sleeve  19  moves distally as a user removes device  10  from a patient&#39;s body. This can occur as needle  17  remains fixedly located relative to housing  11 . Once a distal end of sleeve  19  has moved past a distal end of needle  17 , and needle  17  is covered, sleeve  19  can be locked. Such locking can include locking any proximal movement of sleeve  19  relative to housing  11 . 
     Another form of needle retraction can occur if needle  17  is moved relative to housing  11 . Such movement can occur if the cartridge  18  within housing  11  is moved in a proximal direction relative to 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 needle  17  and housing  11  can be locked with a locking mechanism. In addition, button  13  or other components of device  10  can be locked as required. 
       FIG. 2  shows an injector device  20  of a first embodiment, including a housing  21 , a needle unit  22 , a needle sleeve  23 , a piston rod  24 , a piston spring  25 , and a release mechanism  26 . The piston rod  24  is configured to move within the housing  21  in a longitudinal direction of the injector device  20 . The piston rod  24  is prevented from rotational movement within the housing by appropriate co-operating features (not shown) on the piston rod  24  and either the housing  21  or a rear cap  35  at an end of the housing  21 . 
     The injector device  20  includes a distal end D and a proximal end 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. References hereinafter to “distal” and “proximal” are made in reference to the distal and proximal ends D, P respectively of the injector device  20 . The housing  21  is configured to contain a medicament cartridge  27 , as shown in  FIG. 2 . Such a medicament cartridge  27  includes a cylindrical container  28  having a distal end which is sealed with a pierceable seal  29  and a proximal end which is sealed with a piston  30  disposed within the proximal end of the container  28 . Medicament  31  is held within the container  28  between the piercable seal  29  and the piston  30 . 
     The needle unit  22  includes a needle  32  held in a needle holder  33  connected to the distal end of the housing  21 . The needle sleeve  23  is connected to the housing  21  and configured to slide within the housing  21  in a longitudinal direction of the injector device  20 . The needle sleeve  23  is moveable between an extended position and a retracted position. In the extended position, the needle sleeve  23  surrounds and shields the needle  32 . In the retracted position, the needle  32  is exposed beyond the end of the needle sleeve  23 . The needle sleeve  23  is shown in the extended position in  FIG. 2 . Also shown in  FIG. 2  is an end cap  34  that initially covers the end of the needle sleeve  23  before use of the injector device  20 . 
     The proximal end of the injector device  20  includes the rear cap  35  which is retained in place by locking arms  36  which engage with corresponding locking portions  37  formed on the housing  21  (see  FIG. 4 ). 
     The piston spring  25  is disposed around an elongate projection  38  extending from the rear cap  35 . The piston rod  24  has a hollow bore and is disposed over the elongate projection  38  and piston spring  25  such that the elongate projection  38  and piston spring  25  are received within the hollow bore of the piston rod  24 . The piston spring  25  is in contact with the rear cap and urges the piston rod  24  in a distal direction of the injector device  20 . When a medicament cartridge  27  is received within the injector device, the piston rod  24  is in contact with the piston  30  and is configured to drive the piston  30  within the container  28  once the piston rod  24  is released. 
     The release mechanism  26  can be seen in more detail in  FIGS. 3 and 4 , which show the injector device  20  in an initial, starting position, before a medicament delivery process is commenced, and also with reference to  FIG. 5 . The release mechanism  26  includes a rotatable element  39  (hereinafter referred to as “rotator” for brevity) which is in cooperating engagement with the needle sleeve  23  and piston rod  24  in the starting position, as described hereafter. The rotator  39  is shown in isolation in  FIG. 5 . The rotator  39  is moveably mounted within the housing  21  so as to be able to rotate within the housing  21  about a longitudinal axis of the housing  21 . The rotator  39  includes a hollow cylindrical component having a first section  40  of a first diameter and a second section  41  of a second diameter which is less than the first diameter. The rotator  39  includes an outer guide track  42  including a recessed channel formed in an outer surface of the first section  40 . The outer guide track  42  is formed in a helical path and spirals around the outer surface of the first section. The outer guide track  42  is open at the distal end of the first section  40  of the rotator  39 . In the exemplary embodiment shown, the outer guide track  42  extends around 90 degrees of the circumference of the rotator  39 . 
     The rotator  39  further includes an inner guide track  43  including a recessed channel formed in an inner surface of the first and second sections  40 ,  41 . The inner guide track  43  includes a first portion  44  which extends around a portion of the inner circumference of the inner surface of the second section  41  of the rotator  39 . In the exemplary embodiment shown, the first portion  44  of the inner guide track  43  extends around 90 degrees of the inner circumference of the rotator  39 . The inner guide track  43  also includes a second portion  45  which extends longitudinally along the inner surface of the second section  41  of the rotator  39 , but does not extend circumferentially around the inner surface of the rotator  39 . The first and second portions  44 ,  45  are connected at a right-angle, and the opposite end of the second portion  45  is open at a remote end of the first section of the rotator  39  that is distal to the second section  41 . 
     The release mechanism  26  further includes a first pin  46  projecting inwardly from an inner face of the needle sleeve  23 . The first pin  46  is configured to be received in the outer guide track  42 . The release mechanism  26  further includes a second pin  47  projecting outwardly from an outer face of the piston rod  24  proximate a proximal end of the piston rod  24 . The second pin  47  is received in the inner guide track  43 . In the starting position shown in  FIGS. 3 and 4 , the second pin  47  is disposed at the end of the first portion  44  of the inner guide track  43  remote from the second portion  45 . Although the rotator  39  is rotatable within the housing  21 , it cannot move longitudinally in an axial direction of the housing. Longitudinal movement of the rotator  39  within the housing  21  is prevented by cooperating features (not shown) on the rotator  39  and either the end cap  35  or housing  21 . 
     The second pin  47  being located within the first portion  44  of the inner guide track  43  thereby prevents the piston rod  24  from moving towards the distal end D of the injector device  20  under the force of the piston spring  25 . 
     Operation of the injector device  20  of the first embodiment will now be described. The injector device  20  is initially in the starting position in which the release mechanism  26  is configured as shown in  FIGS. 3 and 4 . The first pin  46  on the needle sleeve  23  is disposed distal to the end of the first section  41  of the rotator  39  and axially aligned with the open end of the outer guide track  42  at the distal end of the first section  40  of the rotator  39 . The second pin  47  disposed at the end of the first portion  44  of the inner guide track  43  remote from the second portion  45 . 
     A user first removes the end cap  34  and then places the end of the needle sleeve against the intended injection site on the patient&#39;s skin. The user then presses the injector device  20  towards the patient&#39;s skin which causes the needle sleeve  23  to move into the housing  21  from its extended position to its retracted position. As needle sleeve  23  retracts into the housing  21 , it engages the needle unit  22  so that the needle unit  22  moves in the proximal direction with the needle sleeve  23  such that the needle  32  engages and pierces the pierceable seal  29  of the cartridge  27 . Further movement of the needle sleeve  23  into the housing  21  results in the needle unit  22  disengaging from the needle sleeve  23  such that the injection needle  32  is exposed and pierces the patient&#39;s skin in order for medicament to be delivered to the patient through the needle  32 . Also as the needle sleeve  23  retracts into the housing, the first pin  46  on the needle sleeve  23  enters and travels along the outer guide track  42  of the rotator  39 . Since the outer guide track  42  defines a helical path around the outside of the rotator  39 , and the needle sleeve  23  moves linearly into the housing  21  without rotating, the rotator  39  is caused to rotate about the longitudinal axis of the injector device  20  within the housing  21 . The rotator  39  rotates relative to the piston rod  24 , and so the second pin  47  on the piston rod  24  is caused to move along the first portion  44  of the inner guide track  43 . When the second pin  47  reaches the second portion  45  of the inner guide track  43 , the piston rod  24  is then in a release position and is free to travel in a distal direction of the injector device  20  under the biasing force of the piston spring  25 . During such movement, the second pin  47  travels longitudinally along the straight second portion  45  of the inner guide track  43 . 
     As the piston rod  24  moves under the force of the piston spring  24 , it pushes against the piston  30  of the medicament cartridge  27 . It can be seen from  FIG. 2  that in an initial configuration, before use, the needle unit  22  and medicament cartridge  27  are disposed within the housing  21  such that the needle  32  is spaced from the pierceable seal  29 . As described above, in one embodiment, initial movement of the needle sleeve  23  causes the needle  32  to pierce the pierceable seal  29  before an injection procedure commences. Alternatively, however, as the medicament cartridge  27  is initially sealed by the pierceable seal  29  and the piston  30 , the piston  30  cannot be pushed into the cylindrical container  28  and so the piston rod  24  may push the whole medicament cartridge  27  towards the needle unit  22 , which may be fixed within the housing  21 , until the needle  32  engages and pierces the pierceable seal  29 . The distal end of the medicament cartridge then abuts the needle unit  22  and so cannot move further in the distal direction of the injector device  20 . Thereafter, the piston rod  24  pushes the piston  30  into the cylindrical container  28  to cause the medicament  31  to be delivered into the patient&#39;s skin through the needle  32 . 
     In a further alternative embodiment, as needle sleeve  23  retracts into the housing  21 , it engages the needle unit  22  so that the needle unit  22  moves in the proximal direction with the needle sleeve  23  such that the needle  32  engages and pierces the pierceable seal  29  of the cartridge  27 . Activation of the release mechanism  26  as described above may occur as the needle unit  22  engages the medicament cartridge  27 , or may occur by further movement of the needle sleeve  23  into the housing  21  after the needle unit  22  disengages from the needle sleeve  23 . However, the needle  32  may not yet pierce the patient&#39;s skin through movement of the needle sleeve  23  into the housing. Once the release mechanism  26  is activated as described above, the piston rod  24  may move under the force of the piston spring  24 , pushing against the piston  30  of the medicament cartridge  27  such that the whole medicament cartridge  27  with engaged needle unit  22  is moved in the distal direction such that the needle  32  pierces the patient&#39;s skin and then the piston rod  24  pushes the piston  30  into the cylindrical container  28  to cause the medicament  31  to be delivered into the patient&#39;s skin through the needle  32 . 
     In a further alternative embodiment, the medicament cartridge  27  may be fixedly secured within the housing  21 . In such an embodiment, as needle sleeve  23  retracts into the housing  21 , it engages the needle unit  22  so that the needle unit  22  moves in the proximal direction with the needle sleeve  23  such that the needle  32  engages and pierces the pierceable seal  29  of the cartridge  27 . Further movement of the needle sleeve  23  into the housing  21  results in the needle unit  22  disengaging from the needle sleeve  23  such that the injection needle  32  is exposed and pierces the patient&#39;s skin in order for medicament to be delivered to the patient through the needle  32 . Also as the needle sleeve  23  retracts into the housing, the release mechanism  26  is activated as described above. As the piston rod  24  moves under the force of the piston spring  25 , it pushes against the piston  30  of the medicament cartridge  27  and pushes the piston  30  into the cylindrical container  28  to cause the medicament  31  to be delivered into the patient&#39;s skin through the needle  32 . 
     Once the medicament delivery process is complete, the user moves the injector device away from the patient&#39;s skin and the needle  32  is withdrawn from the skin. The needle sleeve  23  then moves back into the extended position to surround and conceal the needle  32  to prevent the user accidentally injuring themselves on the needle  32 . A locking mechanism (not shown) may be provided to lock the needle sleeve  23  in the extended position after use of the device. 
       FIG. 8  shows an injector device  120  of a second embodiment in which features in common with the injector device  20  of the first embodiment retain the same reference numerals and detailed description thereof will not be repeated. The injector device  120  of the second embodiment includes a housing  21 , a needle sleeve  23 , a piston rod  24 , a piston spring  25 , and a release mechanism  26  as described previously with respect to the injector device  20  of the first embodiment. 
     A difference with the injector device  120  of the second embodiment is that the housing  21  is configured to contain a different type of medicament container, namely a pre-filled syringe  127  instead of a medicament cartridge  27  as in the first embodiment. The pre-filled syringe includes a cylindrical body  128  having a distal end which a needle  132  is fixed, and a proximal end which is sealed with a piston  130  disposed within the proximal end of the cylindrical body  128 . Medicament  31  is held within the cylindrical body  128  between the needle  132  and the piston  130 . The pre-filled syringe  127  is fixedly retained within the housing  21 . In the exemplary embodiment shown, the pre-filled syringe is held in a syringe holder  133  within the housing  21 . 
     A needle cap  129  is provided around the needle  132  and is in frictional engagement with a narrowed portion of the cylindrical body  128  at its distal end that retains the needle  132 . The needle cap  129  is received within the end cap  34  and is secured to the end cap  34  such that removal of the end cap  34  causes the needle cap  129  to be separated from the cylindrical body  128 . The needle cap  129  may be secured to the end cap  34  by frictional engagement or by bonding, or by being otherwise mechanically secured to the end cap  34 . 
     As with the injector device  20  of the first embodiment, the needle sleeve  23  is configured to slide within the housing  21  between an extended position in which the needle sleeve  23  surrounds the needle  132  and a retracted position in which the needle  132  is exposed beyond the end of the needle sleeve  23 . The needle sleeve  23  is shown in the extended position in  FIG. 8 . 
     The release mechanism  26  is as described previously with respect to the injector device  20  of the first embodiment and so will not be described again. 
     Operation of the injector device  120  of the second embodiment will now be described. The injector device  120  is initially in the starting position in which the release mechanism  26  is configured as shown in  FIG. 8 . The first pin  46  on the needle sleeve  23  is disposed distal to the end of the first section  41  of the rotator  39  and axially aligned with the open end of the outer guide track  42  at the distal end of the first section  40  of the rotator  39 . The second pin  47  is disposed at the end of the first portion  44  of the inner guide track  43  remote from the second portion  45 . 
     A user first removes the end cap  34  and with it the needle cap  129 , and then places the end of the needle sleeve  23  against the intended injection site on the patient&#39;s skin. The user then presses the injector device  20  towards the patient&#39;s skin which causes the needle sleeve  23  to move into the housing  21  from its extended position to its retracted position. As needle sleeve  23  retracts into the housing  21 , the needle  132  is exposed and pierces the patient&#39;s skin. Also as the needle sleeve  23  retracts into the housing, the first pin  46  on the needle sleeve  23  enters and travels along the outer guide track  42  of the rotator  39 . Since the outer guide track  42  defines a helical path around the outside of the rotator  39 , and the needle sleeve  23  moves linearly into the housing  21  without rotating, the rotator  39  is caused to rotate about the longitudinal axis of the injector device  20  within the housing  21 . The rotator  39  rotates relative to the piston rod  24 , and so the second pin  47  on the piston rod  24  is caused to move along the first portion  44  of the inner guide track  43 . When the second pin  47  reaches the second portion  45  of the inner guide track  43 , the piston rod  24  is then in a release position and is free to travel in a distal direction of the injector device  20  under the biasing force of the piston spring  25 . During such movement, the second pin  47  travels longitudinally along the straight second portion  45  of the inner guide track  43 . 
     As the piston rod  24  moves under the force of the piston spring  24 , it pushes against the piston  130  of the pre-filled syringe  127 . Since the pre-filled syringe  127  is fixedly held within the housing  21 , the piston rod  24  pushes the piston  130  into the cylindrical body  128  of the pre-filled syringe  127  to cause the medicament  31  to be delivered into the patient&#39;s skin through the needle  132 . 
     Once the medicament delivery process is complete, the user moves the injector device  120  away from the patient&#39;s skin and the needle  132  is withdrawn from the skin. The needle sleeve  23  then moves back into the extended position to surround and conceal the needle  132  to prevent the user accidentally injuring themselves on the needle  132 . A locking mechanism (not shown) may be provided to lock the needle sleeve  23  in the extended position after use of the device. 
     Although the above description and accompanying drawings describe injector devices  20 ,  120  of first and second embodiments, variations are envisaged. For example, although the outer guide track  42  is described as being formed on the rotator  39  and the first pin  46  is described as being formed on the needle sleeve  23 , these features may be reversed such that the outer guide track  42  is formed on the needle sleeve  23  and the first pin  46  is formed on the rotator  39 . 
     Similarly to the above, although the inner guide track  43  is described as being formed on the rotator  39  and the second pin  47  is described as being formed on the piston rod  24 , these features may be reversed such that the inner guide track  43  is formed on the piston rod  24  and the second pin  47  is formed on the rotator  39 . 
     In the embodiments described above, the outer and inner guide tracks are described as being recessed into the rotator  39  (or needle sleeve  23  or piston rod  24  respectively). However, in an alternative embodiment, the outer and/or the inner guide tracks may be defined by upstanding walls or ribs formed on the rotator  39 , needle sleeve  23  or piston rod  24  respectively. Furthermore, in another alternative embodiment, the outer and/or the inner guide tracks may be defined by open slots extending entirely through the wall of the rotator  39 , needle sleeve  23  or piston rod  24  respectively. 
     Although in the embodiments described above, one outer guide track  42  and one first projection  46  is described, two outer guide tracks  42  and two respective first projections  46  may be provided, or more generally a plurality of outer guide tracks  42  and a plurality of respective first projections  46  may be provided. 
     Similarly to the above, although in the embodiments described above, one inner guide track  43  and one second projection  47  is described, two inner guide tracks  43  and two respective second projections  47  may be provided, or more generally a plurality of inner guide tracks  43  and a plurality of respective second projections  47  may be provided. A plurality of outer/inner guide tracks and respective first/second projections may advantageously help towards providing more stable relative movement of the needle sleeve and rotator, and rotator and piston rod. 
     In the embodiments described above, the outer guide track advantageously extends around 90 degrees of the circumference of the rotator  39 , although it is not limited to this angular value. In alternative embodiments, the outer guide track may extend around more or less than 90 degrees of the circumference of the rotator. 
     Similarly to the above, although the first portion  44  of the inner guide track  43  advantageously extends around 90 degrees of the circumference of the rotator  39 , it is not limited to this angular value. In alternative embodiments, the first portion  44  of the inner guide track  43  may extend around more or less than 90 degrees of the circumference of the rotator  39 . 
     In the embodiments described above, the first portion  44  of the inner guide track  43  extends circumferentially around the rotator  39 , in a direction perpendicular to the longitudinal axis of the rotator  39 . That is, the path of the first portion  44  of the inner guide track  43  does not extend in a longitudinal or axial direction of the rotator. However, it is not limited to this particular configuration of first portion  44  of the inner guide track  43 . In alternative embodiments, the first portion  44  of the inner guide track  43  may be of a helical shape, formed with a shallow screw pitch such that the path of the first portion  44  of the inner guide track  43  extends in a longitudinal or axial direction of the rotator  39 . This may advantageously help toward reducing the force necessary to rotate the rotator  39  as the piston spring  25  would help urge the piston  24  and associated second projections  47  along the first portion  44  of the inner guide track  43 . However, it is important that the first portion  44  of the inner guide track  43  is self-locking with respect to the piston rod  24 . That is, the pitch of the first portion  44  of the inner guide track  43  must not be large enough that the piston rod  24 , under the force of the piston spring  25 , can rotate the rotator  39  and automatically release the piston rod  24 . 
     The first and second embodiments of injector devices described herein respectively are configured to receive a cartridge of medicament and a syringe pre-filled with a medicament. Herein, the term “medicament container” is intended to encompass both a cartridge of medicament and a pre-filled syringe. 
     Although in the embodiments described above, the particular term “pin” is used to describe the first and second pins  46 ,  47  that are received in the outer and inner guide tracks  42 ,  43  respectively, this is exemplary terminology and such features may be termed differently, and are more generally projecting elements which serve as followers in the respective guide tracks. 
     The terms “drug” or “medicament” are used herein to describe one or more pharmaceutically active compounds. As described below, a drug or medicament can include at least one small or large molecule, or combinations thereof, in various types of formulations, for the treatment of one or more diseases. Exemplary pharmaceutically active compounds may include small molecules; 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 of these drugs are also contemplated. 
     The term “drug delivery device” shall encompass any type of device or system configured to dispense a drug into a human or animal body. Without limitation, a drug delivery device may be an injector device (e.g., syringe, pen injector, auto injector, large-volume device, pump, perfusion system, or other device configured for intraocular, subcutaneous, intramuscular, or intravascular delivery), skin patch (e.g., osmotic, chemical, micro-needle), inhaler (e.g., nasal or pulmonary), implantable (e.g., coated stent, capsule), or feeding systems for the gastro-intestinal tract. The presently described drugs may be particularly useful with injector devices that include a needle, e.g., a small gauge needle. 
     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 vessel configured to provide a suitable chamber for storage (e.g., short- or long-term storage) of one or more pharmaceutically active compounds. 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 a drug formulation (e.g., a drug and a diluent, or two different types of 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 of the drug or medicament 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 drug delivery devices and drugs described herein can be used for the treatment and/or prophylaxis of many different types of disorders. Exemplary 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 exemplary disorders are acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis. 
     Exemplary drugs for the treatment and/or prophylaxis of diabetes mellitus or complications associated with 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 term “derivative” refers to any substance which is sufficiently structurally similar to the original substance so as to have substantially similar functionality or activity (e.g., therapeutic effectiveness). 
     Exemplary insulin analogues are Gly(A21), Arg(B31), Arg(B32) human insulin (insulin glargine); Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin. 
     Exemplary insulin derivatives 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-gamma-glutamyl)-des(B30) human insulin; B29-N-(N-lithocholyl-gamma-glutamyl)-des(B30) human insulin; B29-N-(ω-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(ω-carboxyhepta¬decanoyl) human insulin. Exemplary GLP-1, GLP-1 analogues and GLP-1 receptor agonists are, for example: Lixisenatide/AVE0010/ZP10/Lyxumia, Exenatide/Exendin-4/Byetta/Bydureon/ITCA 650/AC-2993 (a 39 amino acid peptide which is produced by the salivary glands of the Gila monster), Liraglutide/Victoza, Semaglutide, Taspoglutide, Syncria/Albiglutide, Dulaglutide, 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 exemplary oligonucleotide is, for example: mipomersen/Kynamro, a cholesterol-reducing antisense therapeutic for the treatment of familial hypercholesterolemia. 
     Exemplary DPP4 inhibitors are Vildagliptin, Sitagliptin, Denagliptin, Saxagliptin, Berberine. 
     Exemplary 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. 
     Exemplary 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 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 include a full-length antibody polypeptide, but that still includes at least a portion of a full-length antibody polypeptide that is capable of binding to an antigen. Antibody fragments can include a cleaved portion of a full length antibody polypeptide, although the term is not limited to such cleaved fragments. Antibody fragments 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, and multispecific antibodies (e.g., diabodies, triabodies, tetrabodies), 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. 
     Exemplary antibodies are anti PCSK-9 mAb (e.g., Alirocumab), anti IL6 mAb (e.g., Sarilumab), and anti IL-4 mAb (e.g., Dupilumab). 
     The compounds described herein may be used in pharmaceutical formulations including (a) the compound(s) or pharmaceutically acceptable salts thereof, and (b) a pharmaceutically acceptable carrier. The compounds may also be used in pharmaceutical formulations that include one or more other active pharmaceutical ingredients or in pharmaceutical formulations in which the present compound or a pharmaceutically acceptable salt thereof is the active ingredient. Accordingly, the pharmaceutical formulations of the present disclosure encompass any formulation made by admixing a compound described herein and a pharmaceutically acceptable carrier. 
     Pharmaceutically acceptable salts of any drug described herein are also contemplated for use in drug delivery devices. 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 an alkali or alkaline earth metal, 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 known to those of skill in the arts. 
     Pharmaceutically acceptable solvates are for example hydrates or alkanolates such as methanolates or ethanolates. 
     Those of skill in the art will understand that modifications (additions and/or removals) of various components of the substances, 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.