Patent Publication Number: US-2022218913-A1

Title: Medicament delivery device adapted for long term storage

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 16/348,847 filed May 9, 2019, which is a U.S. National Phase Application pursuant to 35 U.S.C. § 371 of International Application No. PCT/EP2017/077744 filed Oct. 30, 2017, which claims priority to European Patent Application No. 16199478.5 filed Nov. 18, 2016. The entire disclosure contents of these applications are herewith incorporated by reference into the present application. 
    
    
     TECHNICAL AREA 
     The present disclosure relates to a medicament delivery device comprising a large number of automatic features. 
     BACKGROUND 
     Medicament delivery devices with a number of features, in particular automated features, such as e.g. penetration, injection, withdrawal and covering of medicament delivery members have gained increasing popularity during the last 10-15 years. 
     Many of these highly automated medicament delivery devices, so called auto-injectors, are used for medicament that is to be taken during emergency situations and then often by unexperienced users. One very common medicament that is used in connection with auto-injectors is adrenalin that is administered for emergency treatment of anaphylaxis. 
     There are large numbers of these types of adrenaline medicament delivery devices placed in the society such as schools, museums, shopping malls etc. as emergency devices should a person suffer from an anaphylactic shock. Helping personnel such as teachers, guards, salespersons, etc. could then use an auto-injector with adrenaline to treat the person in chock. 
     These and many other medicament delivery devices with different types of drugs are often stored for long periods before being used. The majority of this type of medicament delivery device is made of components and elements of plastic material that may change properties when aging. Further, many functions of these devices comprise tongues, fingers, arms, levers and other elements that are arranged to flex in different directions for releasing or locking functional components. 
     For example the medicament delivery device disclosed in document WO 2013/032389 comprises a number of levers flexible in generally radial directions for holding and releasing a medicament container holder for performing a penetration, holding and releasing a plunger rod for performing an injection and for blocking the movement of a medicament delivery member guard after removal of the medicament delivery device from the medicament delivery site. Many of these levers, and in particular the levers that block the medicament delivery member guard are in a flexed, tensioned condition in their initial state and flex to a non-tensioned blocking condition when the medicament delivery member guard is to be blocked. 
     However, due to the effects of aging of plastic material and the tensioned condition, the levers may lose their flexing properties to a large extent, which may jeopardize the blocking capabilities of the levers, and thus may risk injuries if it is possible to move the medicament delivery member guard so that the medicament delivery member is exposed. 
     SUMMARY 
     The aim of the disclosure is to remedy the drawbacks of the state of the art medicament delivery devices and to provide a solution that will ensure full functionality even after longer storage periods. 
     The aim of the present disclosure is solved by a medicament delivery device comprising the features of the independent patent claims. Preferable embodiments of the disclosure form the subject of the dependent patent claims. 
     According to a main aspect of the disclosure, it comprises a medicament delivery device that may comprise a housing and a medicament container holder arranged to accommodate a medicament container. Further the medicament delivery device may comprise a power unit arranged to act on said medicament container for expelling a dose of medicament when activated as well as an activation mechanism operably connected to the power unit, capable of activating the power unit. 
     Preferably the activation unit comprises a medicament delivery member guard movable in a longitudinal direction in relation to said housing such that when a proximal end of the medicament delivery device is pressed against a dose delivery site, wherein the activation unit may comprise a force element arranged to bias the medicament delivery member guard to a proximal extended position wherein the medicament delivery member is covered. 
     The medicament delivery device may further comprise a locking mechanism operably arranged to lock the medicament delivery member guard in the extended position, wherein the locking mechanism may comprise a number of locking elements flexible in a generally radial direction. The locking mechanism may further comprise ledge surfaces to which the locking elements abut when the medicament delivery member guard is in the extended position, preventing any further movement of the medicament delivery member guard in the distal direction. This will effectively prevent any accidents of exposed medicament delivery members that otherwise may cause injuries like needle sticks. 
     According to a favourable solution, the medicament delivery device may be arranged with spaces connected to the housing in which the locking elements are positioned in a non-tensioned state in a delivery mode of the medicament delivery device. With this solution, the locking elements will not be in a tensioned state for longer periods of time when delivered and stored for future use. The material of the locking elements will thus not be affected and altered due to tensions in the material, thus ensuring proper functioning and flexing action of the locking elements when the medicament delivery device is used, even after longer times of storage. 
     The spaces may be recesses or cut-outs on the inner surface of the housing or on adjacent parts. According to one aspect of the disclosure, the spaces may be arranged on at least one separate component attached inside the housing of the medicament delivery device. With this solution it is easier to create the spaces or recesses than in the housing itself, because the latter is difficult from a manufacturing perspective. The separate component may be permanently or releasably attached to the housing. 
     Further, the separate component may comprise an elongated plate-shaped member, and the housing may be arranged with support elements preventing movement of the component when assembled. In that regard, the support elements may comprise a transversal stop element arranged to abut a proximal end of the at least one component. The transversal stop element may be comprised in the housing. This solution enables the plate-shaped member to be pushed or slid into the housing from a distal direction via the support elements until it is positioned by the abutment to the transversal stop element. Preferably the support elements may comprise longitudinally extending ledges arranged to support the at least one component in all transversal directions. 
     In order to fixate the plate-shaped member, the support elements may comprise a transversal stop element arranged to abut a distal end of the at least one component and according to one aspect, the support element may be comprised in a component attachable to the housing, such as an end cap that is attached to the distal end of the housing. 
     Further, the at least one element may also comprise the ledge surfaces of the locking mechanism. This has the advantage that the manufacturing is facilitated in that the manufacturing and the molds of the housing are less complex. 
     These and other aspects of, and advantages with, the present disclosure will become apparent from the following detailed description of the disclosure and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In the following detailed description of the disclosure, reference will be made to the accompanying drawings, of which 
         FIG. 1  is an exploded view of one embodiment of a medicament delivery device comprising the present disclosure, 
         FIG. 2  is a detailed views of components comprised in the medicament delivery, 
         FIG. 3  is a detailed views of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 4A  is a cross-sectional view of the medicament delivery device of  FIG. 1 , 
         FIG. 4B  is a cross-sectional views of the medicament delivery device of  FIG. 1 , 
         FIG. 5A  is a cross-sectional view of a power unit comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 5B  is a cross-sectional view of a power unit comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 6  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 7A  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 7B  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 8  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 9  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 10  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 11A  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 11B  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 12  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 13  is a detailed view of components comprised in the medicament delivery device of  FIG. 1 , 
         FIG. 14A  is a view of a different functional stage of the medicament delivery device of  FIG. 1 , 
         FIG. 14B  is a view of a different functional stage of the medicament delivery device of  FIG. 1 , 
         FIG. 15  is a view of a different functional stage of the medicament delivery device of  FIG. 1 , 
         FIG. 16  is a view of a different functional stage of the medicament delivery device of  FIG. 1 , 
         FIG. 17  is a view of a different functional stage of the medicament delivery device of  FIG. 1 , and 
         FIG. 18  is a view of a different functional stage of the medicament delivery device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to a medicament delivery device provided with an elongated housing  10  extending along a longitudinal axis L and having a proximal end  12  and distal end  14 . The proximal end of the housing  10  is arranged with a tubular section  16 , onto which a protective cap  164  is arranged to be releasably attached. A transversal transitional wall  20  is arranged between the tubular section  16  and the rest of the housing  10 . The distal end  14  of the housing is arranged with a central opening  22 , to which an end cap  138  may be attached. The distal area of the housing is arranged with arms  29  that are flexible in a generally radial direction, which arms are arranged with inwardly directed ledges for attaching the end cap  138  as will be described below. Further the proximal end  12  of the housing  10  is arranged with an opening  26 . Moreover, an opening or window  28  is arranged on the side of the housing. 
     A medicament delivery member guard, in the embodiment shown comprising a front medicament delivery member guard  30  and a rear medicament delivery member guard  48  that are comprised in an activation mechanism as will be described,  FIGS. 1 and 2 , is further arranged slidable in the housing  10 . The front medicament delivery member guard  30  is arranged with a proximal generally tubular part  32  that may protrude through the opening  26  at the proximal end of the housing. The tubular part  32  is arranged with proximally directed tongues  34  formed in the tubular part  32  by U-shaped cut-outs. The tongues  34  are flexible in the generally radial direction and are arranged with outwardly extending protrusions  36 . At the distal end of the proximal part  32 , two generally flat arms  38  are extending in the distal direction. At the junction between the proximal part  32  and the arms  38 , tongues  40  are attached, which extend in the distal direction at some outwards inclination in relation to a longitudinal axis. The tongues  40  are designed and attached to the proximal part  32  such that proximal end surfaces  42  of the tongues  40  are created. At a distal end of the arms  38 , cut-outs  44  are arranged. Further, protrusions  46  are positioned on the inner surface of the arms  38  proximal of and adjacent the cut-outs  44 . Distally directed end surfaces of the protrusions  46  are arranged to abut proximal end surfaces of the rear medicament delivery member guard  48 . The rear medicament delivery member guard  48  is arranged as a tubular body  50 . At a proximal area of the tubular body  50 , two radially extending ledges  52  are arranged around the circumference. Between the two ledges  52  are rectangular cut-outs  54  that extend in the longitudinal direction. At the distal end of the tubular body  50 , two arms  56  are extending in the distal direction. The arms  56  are provided with rectangular cut-outs  58 . 
     Further, inside and coaxial with the medicament delivery member guard  30  is a medicament container holder  60 ,  FIGS. 1 and 3 , having a general C-shape as seen in a cross-sectional view. The medicament container holder  60  is arranged to contain a medicament container  62  that in the embodiment shown is a generally elongated syringe with a fixed injection needle  64  at its proximal end and having a movable stopper  65  enclosing the distal end of the medicament container  62 ,  FIG. 4 . The injection needle  64  is preferably protected by a suitable medicament delivery member shield  66 ,  FIG. 4 a   . In the embodiment shown the medicament delivery member shield  66  is a so called flexible needle shield or FNS. It is however to be understood that other types of medicament delivery member shields are feasible within the disclosure. 
     The distal end of the medicament container  62  is arranged with a generally radially extending flange  68 , and the medicament container holder  60  is provided with a recess  70  in which the flange  68  fits,  FIG. 3 . In order to secure the medicament container  62  in the medicament container holder  60  a generally C-shaped clip  72  is arranged which is designed to fit into the recess  70  and to engage with the walls of the recess  70  in order to securely hold the medicament container  62  inside the medicament container holder  60 . At the distal end of the medicament container holder  60 , recesses  74  are arranged. These recesses  74  are designed to interact with proximally directed tongues  76  having outwardly directed ledges  78 , which ledges  78  fit into the recesses  74 . The proximally directed tongues  76  are attached to a generally tubular plunger holder  80 , which plunger holder  80  is comprised in a power unit  81  of the medicament delivery device, shown in  FIG. 5 . Adjacent the attachment points of the tongues  76 , generally radially extending ledges  82  are arranged. Further, cut-outs  84  are arranged on opposite sides of the body, having generally rectangular shapes. At the distal end of the plunger holder, two recesses  86  are arranged on opposite sides thereof. 
     The plunger holder  80  is further arranged with two distally directed arms  88  on opposite sides that are flexible in the generally radial direction. The free ends of the arms  88  are arranged with inwardly directed ledges  90 ,  FIG. 5 , and outwardly directed surfaces of the arms  88  are arranged with radially directed protrusions  92 . The inwardly directed ledges  90  are designed to interact with circumferential recesses  94  on an outer surface of an elongated plunger rod  96 ,  FIG. 6 , which plunger rod  96  is arranged slidable in a longitudinal direction inside the plunger holder  80 . The plunger rod  96  is further arranged with a circumferential, proximally directed, ledge  97  positioned at a predetermined distance from the proximal end of the plunger rod. A drive spring  98 ,  FIGS. 1 and 5 , that in the embodiments shown is a compression spring is comprised in the power unit. The drive spring  98  is arranged between a proximal end wall  100  of the plunger rod  96  and a distal end wall  102  of the plunger holder  80 ,  FIG. 5 a   . An elongated spring guide rod  104 ,  FIG. 4 a   , is arranged inside the drive spring  98  for preventing buckling of the drive spring  98 . Adjacent the free ends of the arms  88  two distally directed support ledges  105 ,  FIG. 3 , are arranged on opposite sides, the function of which will be described below. 
     Coaxial with, and positioned radially outside the plunger holder, is an actuator  106 ,  FIGS. 7 to 9 , having a generally tubular first body  108 . At a distal end of the first body two distally directed arms  110  are arranged, being flexible in the generally radial direction. The free ends of the arms  110  are arranged with inwardly directed ledges  112 . The ledges  112  of the arms are arranged to fit into the recesses  86  of the plunger holder  80  for releasably holding the plunger holder  80  as will be described below. Outside the tubular first body  108  and coaxial therewith is a tubular second body  114 , where the bodies are attached to each other by longitudinally extending ribs  116 . The second body  114  is arranged with two proximally directed tongues  118  that are flexible in the generally radial direction. The free ends of the tongues  118  are arranged with inwardly directed ledges  120 . The second body  114  is arranged with longitudinally extending slits  122  which terminate at the proximal end surface of the second body  114 . Further, end sections  124  are arranged between the first and the second bodies, which end sections  124  are arranged with two generally rectangular first passages  126  and a centrally positioned generally rectangular second passage  128 . 
     The actuator is held stationary by an actuator lock  130  in the form of a generally U-shaped element. Proximally directed arms  132  of the actuator lock  130  are arranged with generally rectangular cut-outs  134  extending along the arms  132 . Each cut-out  134  is provided with distally directed tongues  136  that have a certain outwardly inclination. The proximally directed arms  132  are designed to fit in the rectangular second passage  128  and the annular space between the first  108  and the second  114  bodies and extend such that the distal ends of the tongues  136  are designed to move out into the slits  122  of the second body and be resting with their end surfaces against proximally directed end surfaces of the slits  122 , thereby locking them relative each other as seen in  FIG. 7B . 
     An end cap  138  is further provided for the medicament delivery device,  FIG. 8 . It comprises a generally dome-shaped body  140  arranged to cover the distal end of the housing. A number of support beams  142  extend in the proximal direction, which support beams  142  are to rest against the distally directed surface of the end sections  124  of the actuator  106 . Further two attachment arms  144  are extending from the body  140  in the proximal direction. The attachment arms  144  have a generally rectangular cross-sectional shape and are intended to fit into the generally rectangular first passages  126  of the end sections  124  of the actuator  106 . At the proximal area of the attachment arms are generally rectangular cut-outs  146 , which are intended to engage with the inwardly directed ledges  120  of the tongues  118  of the second body  114  of the actuator  106  such that they are locked to each other when the attachment arms  144  are pushed into the first passages  126 . With this solution the actuator  106 , the actuator lock  130  and the end cap  138  are thus locked to each other when assembled. The assembly is in turn attached to the distal end of the housing in that the inwardly directed ledges of the tongues  29  of the housing  10  fit into passages created around the arms of the second body as seen in  FIG. 10 . 
     A number of spring force elements are arranged in the power unit  81  shown in  FIGS. 5A-5B . A medicament delivery member guard spring  148  in the form of a compression spring is arranged between distally directed surfaces of the ledges  52  of the rear needle cover and proximally directed end surfaces of the longitudinal ribs  116  between the first and the second tubular bodies of the actuator  106 . A penetration spring  150  also in the form of a compression spring is arranged between the distally directed support ledges  105  of the plunger holder  80  and proximally directed surfaces of the end sections  124  of the actuator  106 . 
     Further needle cover lock elements  152 ,  FIGS. 2 and 11 , are provided inside the housing of the medicament delivery device. The needle cover lock elements  152  comprise generally elongate plate-shaped members  154  that extend from a proximal end of the second body  114  of the actuator  106  to outside the needle cover as seen in  FIG. 11A . The distal end of the members  154  are provided with cut-outs on each side such that a central part  156  fits into the slit  122  of the second body  114  where distally directed end surfaces of the cut-outs are resting on the proximal end surface of the second body  114  on each side of the slit  122 ,  FIG. 11A . At the proximal area of the members  154  generally rectangular cut-outs  158  are provided, the function of which will be explained. On the inner surface of the members  154  at a proximal area thereof,  FIGS. 2 and 12 , transversal ledges  160  are arranged, designed to interact with the tongues  40  of the medicament delivery member guard  30  as will be described. The needle cover lock element  152  is supported in the proximal area by longitudinally extending guide ledges  162  on the inner surface of the housing  10 . As seen in  FIG. 12 , the guide ledges  162  are arranged such that the needle cover lock element  152  is guided in all directions but the longitudinal. 
     Further, the medicament delivery device is arranged with a front cap  164 ,  FIGS. 1 and 13 , arranged with a distally directed passage  166 . The shape of the passage  166  is to fit onto the proximal section  16  of the housing with a friction fit to releasably hold the front cap  164  onto the housing  10 . The front cap  164  is further arranged with a distally directed generally tubular body  168  having dimensions so as to fit into the proximal end of the medicament delivery member guard  30 . Inside the tubular body a medicament delivery member shield remover is arranged. It comprises a plate-shaped body  170  arranged with three distally directed arms  172 . The ends of the arms  172  are arranged with inwardly directed ledges  174 , which ledges  174  are arranged to engage the outer surface of a medicament delivery member shield  66 . The outer surfaces of the arms  172  are arranged with proximally directed, outwardly inclined, tongues  176 , which tongues  176  are designed to fit into longitudinal slits  178  in the tubular body  168  such that the end surfaces of the tongues rest against a distally directed surface of an end wall  180  of the front cap  164 . 
     The medicament delivery device is intended to function as follows. When the medicament delivery device is assembled, a medicament container  62 , with a medicament delivery member shield  66  attached to the injection needle  64 , is preferably inserted into the medicament container holder  60  and a C-clip  72  is attached so that the medicament container  62  is securely attached to the medicament container holder  60 . A drive spring  98  is inserted into the plunger holder  80  and is tensioned by the plunger rod  96  being pushed in the distal direction into the plunger holder  80  until the ledges  90  of the arms  88  fit into the recesses  94  of the plunger rod  96 . The first body  108  of the actuator  106  is then pushed onto the plunger holder  80  in the proximal direction until the ledges  112  of the arms  110  of the first body  108  fit into the recesses  86  of the plunger holder  80 , whereby the arms  110  are prevented from flexing in the radial direction. The rear medicament delivery member guard  48  is then pushed onto the first body  108  of the actuator  106  such that the arms  88  of the first body  108  are prevented from flexing in the radial direction. Thus, a power pack  81  is formed. 
     The needle cover locks  152  are pushed from the distal end into the housing  10  of the medicament delivery device. In this regard, they are guided and supported in all transversal directions by the guide ledges  162  as seen in  FIG. 12 . The medicament delivery member guard  30  is then entered into the housing from the distal end, whereby the tongues  40  will slide on the inner surface of the needle cover lock elements  152  until they enter the cut-outs  158 , where they will flex outwardly in the radial direction and be positioned in a non-tensioned state or condition in a delivery mode,  FIG. 11B . The medicament container holder  60  is now attached to the plunger holder  80  and the whole assembly is inserted into the housing from the distal end, which causes the needle cover lock elements  152  to be locked in the longitudinal direction by the central part  156  at the distal end of the needle cover locks fitting into the slits  122  of the actuator,  FIG. 11A . Then the distal end of the medicament delivery device is closed by the actuator lock  130  and the end cap  138 . Further, a front cap  164  is attached to the proximal end of the medicament delivery device. 
     When the medicament delivery device is to be used, the front cap  164  is removed by pulling it in the proximal direction. The ledges  174  of the medicament delivery member shield grabber engage the material of the medicament delivery member shield  66  so that the medicament delivery member shield  66  is also pulled off when the front cap  164  is removed. The device is now ready to deliver a dose of medicament. The proximal end of the medicament delivery device is then pressed against a dose delivery site, i.e. the proximal end of the front medicament delivery member guard. This causes the front medicament delivery member guard  30  to move distally in relation to the housing and because the front medicament delivery member guard  30  is connected to the rear medicament delivery member guard  48 , the latter will also move in the distal direction in relation to the housing. Further, the tongues  40  move non-tensioned in the recesses  158  of the members  154  of the needle cover locks  152 ,  FIG. 14A . When the medicament delivery member guard has moved a certain distance, the rectangular cut-outs  58  of the rear medicament delivery member guard  48  will be positioned radially outside the arms  110  of the first body  108  of the actuator  106 , which arms  110  are then free to flex radially outwards, thereby releasing the plunger holder  80 . The plunger holder  80  is now moved in the proximal direction by the force of the penetration spring  150 , whereby the medicament container holder  60  with its medicament container  62  is also moved in the proximal direction, causing a penetration by the injection needle  64  into the dose delivery site,  FIG. 14B . 
     As the plunger holder  80  is moving in the proximal direction during the penetration sequence, it will also move in relation to the first body  108  of the actuator  106 . At the end of the penetration movement, the protrusions  92  of the arms  88  of the plunger holder  80  holding the plunger rod  96  will pass out of contact with the inner surface of the first body  108 ,  FIG. 15 , wherein the arms  88  are free to flex radially outwards, releasing the plunger rod  96 . Because of the drive spring  98 , the plunger rod  96  is now urged in the proximal direction, whereby the stopper  65  of the medicament container  62  is also moved in the proximal direction, causing a dose of medicament to be delivered through the injection needle  64 . The dose delivery sequence is terminated when the proximal circumferential ledge  97  of the plunger rod  96  comes in contact with a distal end surface of the medicament container holder  60 ,  FIG. 16 . 
     The medicament delivery device can now be removed from the dose delivery site. This enables the medicament delivery member guard  30 , to be moved in the proximal direction relative the housing by the medicament delivery member guard spring  148  such that the injection needle  64  is covered by the medicament delivery member guard  30 ,  FIG. 17 . The movement of the medicament delivery member guard  30  is stopped when the proximally directed end surfaces  42  of the inclined tongues  40  of the medicament delivery member guard  30  come in contact with the transitional wall  20  of the housing,  FIG. 18 . The movement of the medicament delivery member guard  30  will also cause the inclined tongues  40  of the medicament delivery member guard  30  to move past the ledges  160  of the needle cover lock elements  152 , which will prevent any movement of the medicament delivery member guard  30  in the distal direction in relation to the housing, thereby preventing any exposure of the injection needle  64 . The medicament delivery device can now be discarded. 
     It is to be understood that the disclosure described above and shown in the drawings is to be regarded only as a non-limiting example and that it may be modified in many ways within the scope of the patent claims.