Abstract:
A medicament delivery device for delivering metered doses of medicament, wherein an indicator mechanism ( 128, 132 ) is operably connected to an drive member ( 118 ) and arranged to visibly indicate to a user of the device when a spring force tensioning member ( 166 ) has been operated such that the device is ready for dose delivery.

Description:
TECHNICAL AREA 
       [0001]    The present invention relates to a medicament delivery device and in particular a device capable of delivering a number of predetermined metered doses. 
       BACKGROUND OF INVENTION 
       [0002]    There are a large number of devices for delivering medication for absorption in the respiratory system or for medicament delivery to the eyes and one strong trend is to develop devices for self-administration. Traditionally oral or nasal medication was intended for treatment of diseases in the trachea, bronchi and/or lungs, and in particular acute or chronic symptoms of asthma. However, much research is now performed on administration of medicament via the lungs in treatment of many other ailments due to beneficial absorption rate and reduced side effects. Further, oral administration provides a greater safety than delivery devices using needles because of the problem with possible contamination from a used needle. A similar situation exists for delivery of medicament to the eyes of a patient. 
         [0003]    However, there are a number of medicament compositions that are not compatible with existing devices and there are further a number of drawbacks with existing devices. For example aerosol dispensers utilise a propellant which provides the force to aerosolize the medicament in liquid form. However, this requires a special type of pressurised canister, usually of metal, which increases the cost for manufacturing and affects the environment. 
         [0004]    One example of a device which could be used for metered oral administration is described in the document WO 2011/043712. The disclosed device comprises a plunger rod, which, when driven by a pre-tensioned helical spring, forces a stopper into a cartridge containing medicament, whereby a dose of medicament is delivered from an administration member. The administration member could be a mouth piece or a nasal piece. 
         [0005]    With the device according to WO 2011/043712, it is possible to set a dose by turning a spring force tensioning member at a distal end of the device. This action also tensions a spiral spring for delivering a dose. The setting and delivery of doses may be made a number of times until the medicament container is empty. 
         [0006]    A drawback with the device of WO 2011/043712 is that there is no indication that a dose has been set and that the device is ready for dose delivery. This may be a drawback where the device user either is not very used to handling the device so that he/she is uncertain that the device has been handled properly for making it ready for dose delivery. Also for experienced users, it is advantageous to be provided with a positive indication that the handling steps prior to dose delivery have been performed correctly. 
         [0007]    There is thus still a need for devices where a number of doses may be delivered and where handling steps need to be performed prior to each dose delivery to be provided with information and/or verification that the handling steps have been performed such that the device is ready for dose delivery. 
       BRIEF DESCRIPTION OF INVENTION 
       [0008]    As used herein, the term “liquid” encompasses all solutions, suspensions, emulsions, oils, gels and so forth, which generally behave as liquids at operating temperatures. The term explicitly includes solid compositions dissolved or dispersed in a liquid carrier. Materials behaving as highly viscous liquids are also included. 
         [0009]    In the present application, when the term “distal part/end” is used, this refers to the part/end of the medical delivery device, or the parts/ends of the members thereof, which during use of the device is located the furthest away from the delivery site of the patient. Correspondingly, when the term “proximal part/end” is used, this refers to the part/end of the device, or the parts/ends of the members thereof, which under use of the device is located closest to the delivery site of the patient. 
         [0010]    The aim of the present invention is to remedy the drawbacks of the state of the art devices. This is obtained by a medicament delivery device according to the features of the independent patent claim  1 . Preferable embodiments of the invention form the subject of the dependent patent claims. 
         [0011]    The present invention pertains to a medicament delivery device for delivering metered doses of medicament. It comprises preferably at least one generally elongated tubular chassis, the chassis having opposite distal and proximal ends. 
         [0012]    Inside said chassis, a threaded plunger rod may be arranged. The plunger rod is arranged to cooperate with a drive nut, which is threadedly connected to the threaded plunger rod. 
         [0013]    The device may further preferably be provided with a drive member. This drive member is preferably rotatably connected to a spring force tensioning member. In a preferred embodiment, the spring force tensioning member is accessible outside the distal end of the chassis. It is however to be understood that the spring force tensioning member may be placed on other locations on the chassis. 
         [0014]    Further, the drive member is preferably connected to the drive nut via an drive member extension such that said drive member extension and said drive member are operably interconnected for providing a rotational lock of the drive member extension in an opposite direction when said drive member is rotated by said spring force tensioning member. 
         [0015]    Also, according to a preferred embodiment, the drive member extension and said drive nut may be operably interconnected for providing a rotational lock of the drive nut in relation to the drive member extension. 
         [0016]    The device is further arranged with spring force member, that in one preferred embodiment is in the form of a spiral spring. It is however to be understood that other types of spring force member may be used for the same function. 
         [0017]    The spring force member has a first end connected to the drive member and a second end connected to a fixed point on the chassis such that said spring force member is tensioned when said spring force tensioning member and said drive member are rotated. 
         [0018]    In order to handle the plunger rod, a guide nut may be arranged with guide ledges which may cooperate with longitudinal grooves of the plunger rod for providing a rotational lock but allowing a longitudinal movement of the plunger rod in relation to the guide nut. 
         [0019]    In order to facilitate the handling of the medicament delivery device, a manually operated activation means is releasably interconnected to said drive member extension by engagement means for providing a rotational locking of the drive member extension in any direction when said drive member is rotated and said spring force member is tensioned by handling said spring force tensioning member for setting the device ready for delivery of a dose of medicament. 
         [0020]    According to the present invention, it is characterised in an indicator mechanism operably connected to said drive member and arranged to visibly indicate to a user of the device when said spring force tensioning member has been operated such that the device is ready for dose delivery. 
         [0021]    In this manner, the user is informed by the indicator mechanism when the spring force tensioning member has been operated to an extent that the device is ready for use. The user is thus provided with positive information and can be assured that when the indication is visible, the device is ready for dose delivery. 
         [0022]    According to one solution, the indicator mechanism may comprise a surface operably connected to said drive member, which surface is arranged with a noticeable indication member, the indicator mechanism further comprising an opening in said chassis for viewing said surface. Thus, when the drive member is turned, the surface is positioned in line with the opening, and is thus visible to the user. 
         [0023]    According to a preferable solution of the invention, the surface may be operably arranged at said drive member such that said indication member is visible in said opening when said spring force tensioning member has been operated, i.e. showing that the device is ready for dose delivery. In this manner, the indicator becomes visible only when the spring force tensioning member, and thus the drive member, has been turned such that a dose has been set and the device is ready for dose delivery. 
         [0024]    In order to be clearly distinctive and easily visible to a user, the indication member comprises a distinct colour. This colour may for example be a clear green colour, indicating a ready device in a positive way. However, the colour may be chosen such that it is a clear alert, such as orange, yellow, possibly also fluorescent. 
         [0025]    In addition to a colour, or instead of a colour, the indication member may comprise indicia. The indicia could for example be a check mark, letters, words like “OK”, a graphic symbol or the like, just to mention a few. 
         [0026]    In order to elevate the visibility further, the opening may be arranged with a magnifying lens or the like, where the indication member is even more clearly visible. 
         [0027]    According to a further aspect of the invention the medicament delivery device is an inhalation device, an eye spray device or an injector. 
         [0028]    These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0029]    In the following detailed description of the invention, reference will be made to the accompanying drawings, of which 
           [0030]      FIG. 1  is a perspective view of a medicament delivery device comprising the present invention, 
           [0031]      FIG. 2  is an exploded view of the proximal part of  FIG. 1 , 
           [0032]      FIG. 3  is a cross-sectional view of the proximal part of  FIG. 2 , 
           [0033]      FIG. 4  is a detailed view of a distal area of the proximal part of  FIG. 2 , 
           [0034]      FIG. 5  is a perspective view of a distal area of the proximal part of  FIG. 2 , 
           [0035]      FIG. 6  is a perspective view of a distal part of the device of  FIG. 1 , 
           [0036]      FIG. 7  is an exploded view of the distal part of  FIG. 6 , 
           [0037]      FIG. 8  is a cross-sectional view of the distal part of  FIG. 6 , 
           [0038]      FIGS. 9-16  are detailed views of components comprised in the distal part of  FIG. 6 , 
           [0039]      FIGS. 17-18  are detailed views showing different functional states. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0040]    One embodiment of a device shown in the drawings comprises a generally elongated body  10 . The body  10  is in the embodiment shown divided into two parts; a proximal part  12  and a distal part  14 ,  FIG. 1 . 
         [0041]    The proximal part  12  comprises generally tubular housing part  16 ,  FIG. 2 . A proximal end of the housing part  16  is arranged with an attachment area  18 ,  FIG. 2 , onto which a medicament delivery member  20  can be releasably attached. The attachment means between the medicament delivery member  20  and the housing  16  could for example be ledges  22  that snap into corresponding grooves  23 ,  FIG. 3 . It is however to be understood that other types of attachment means could be utilized. The medicament delivery member  20  is in the embodiment shown a mouthpiece through which a user inhales when a dose of medicament is to be delivered. It is however to be understood that other types of medicament delivery members could be used, such as nasal pieces, eye pieces and even injection needles and the like. 
         [0042]    The proximal part  12  is further arranged with a generally elongated tubular medicament container holder  24 ,  FIG. 2 , arranged to accommodate a medicament container  26 . The medicament container holder  24  is arranged with generally radially flexing legs  28 ,  FIG. 3 , with outwardly extending ledges  30  that fit into recesses  32  in the housing part  16 . 
         [0043]    The medicament container  26  is in the embodiment shown arranged with a proximal neck  34  and a movable stopper  36  inside the container. At the proximal end of the medicament container holder  24 , a nebulizing nozzle  38  is arranged,  FIGS. 2 and 3 . The nebulizing nozzle  38  contains a chip (not shown) with a plurality of micro channels capable of creating an aerosol of droplets of medicament. 
         [0044]    A medicament container guide member  40 ,  FIGS. 2 and 3 , is arranged with a central passage and is intended to be pushed onto the medicament container  26  from its proximal end and into contact with an annular ledge  42  ( FIG. 4 ) at a distal end of the medicament container  26 ,  FIG. 2 . The medicament container guide member  40  is arranged with a number of proximally extending arms  44 ,  FIG. 3 , arranged generally radially flexible and having outwardly extending protrusions  46 . These protrusions  46  are arranged to grip around an annular ledge  48  of the housing for locking the medicament container guide member  40  and thus the medicament container  26  in the radial direction. 
         [0045]    A medicament holder locking member  50 ,  FIG. 4 , is arranged to be pushed into the distal end of the medicament container holder  24 , and moved in contact with a distally directed end surface of the medicament container  24 . The medicament holder locking member  50  is arranged with a central passage  52  and is provided with a number of generally radially flexible tongues  54  having outwardly extending protrusions  56 ,  FIG. 4 . These protrusions  56  are arranged to fit into recesses  58  on inner surfaces of the medicament container guide member  40  such that when the medicament holder locking member  50  is in place, the medicament container  26  is locked in the axial direction. 
         [0046]    The distal part  14  is arranged with a housing. In the embodiment shown the housing is designed as two housing halves  60 ,  62 ,  FIG. 6 . It is however to be understood that the housing may be arranged in other ways and in more parts without departing from the scope of the invention. 
         [0047]    Inside the housing parts, a generally tubular chassis  64  is arranged,  FIGS. 7 ,  9 ,  10 . It is arranged with a transversal interior wall  66 ,  FIGS. 9 and 10 . The interior wall  66  is further provided with a central passage  68 . At a proximal end of the chassis, attachment means  70 ,  FIG. 6 , are arranged, in the embodiment shown as grooves for a bayonet connection. In this context it is to be understood that other types of attachment means may be employed, such as threads, snap-on fittings or the like, all within the imagination of the person skilled in the art. The attachment means  70  of the chassis  64  are intended to interact with corresponding attachment means  72  on the distal end of the generally tubular housing part  16 ,  FIG. 5 . 
         [0048]    Coaxially arranged inside the chassis  64  and extending in the longitudinal direction of the device is an elongated plunger rod  74 ,  FIGS. 6 and 7 . The plunger rod  74  is intended to be in contact with a stopper arranged in the medicament container. The plunger rod  74  is arranged inside a so called drive member extension  76 ,  FIGS. 11 and 12 , having a generally tubular shape. A proximal end of the drive member extension  76  is arranged with spline grooves  78  on its outer surface,  FIGS. 11 and 12 . The spline grooves  78  mate with corresponding spline ridges  80  on an inner surface of a generally tubularly shaped drive nut  82 ,  FIG. 11 . 
         [0049]    The inner surface of the drive nut  82 ,  FIG. 11 , is further provided with threads  84 , which cooperate with threads  86  on the outer surface of the plunger rod  74 . The drive nut  82  is further arranged with an annular ledge  88  with a distally directed end surface having a number of slanting wedge-shaped surfaces  90 . The proximally directed surface of the interior wall  66  of the chassis  64  is arranged with corresponding slanting wedge-shaped surfaces  92 ,  FIG. 9 . 
         [0050]    The plunger rod  74  is further arranged through a guide nut  94 ,  FIG. 11 . The guide nut  94  is arranged with guide ledges  96  which cooperate with longitudinal grooves  98  of the plunger rod  74 ,  FIG. 6 , providing a rotational lock but allowing a longitudinal movement of the plunger rod  74  in relation to the guide nut  94 . The guide nut  94  fits into a guide nut lock member  100 , which is attached to the chassis  64  via radially outwardly extending protrusions  102  fitting into recesses  104  in the interior surface of the chassis  64 ,  FIG. 9 . The nut lock member  100  is arranged with tongues  106  that are arranged flexible in the generally radial direction. The inner surfaces of the flexible tongues  106  are arranged with wedge-shaped teeth  108 ,  FIG. 11 , extending in the radial direction. The teeth  108  of the tongues  106  are intended to engage corresponding wedge-shaped teeth  110  arranged around the circumference of the guide nut  94 . 
         [0051]    Further, the drive member extension  76  is arranged with a ring-shaped part  112 ,  FIG. 11 , with a hollow interior, where the inner surface of the interior is arranged with transversal stop ledges  114 . These stop ledges  114  cooperate with flexible arms  116  arranged at a proximal end of a generally elongated drive member  118 ,  FIG. 12 . 
         [0052]    However the stop ledges  114  and flexible arms  116  are arranged to provide a unidirectional lock such that the drive member  118  may only be rotated in one direction in relation to the drive member extension, where the flexible arms  116  slide over the stop ledges  114 . In the other direction, the ends of the flexible arms  116  abut the stop ledges  114 , thereby blocking their relative rotation. The drive member  118  is further arranged with a disk-shaped member  120 ,  FIG. 12 . On the proximally directed side of the disk-shaped member  120 , two stop ledges  122  are arranged diametrically on opposite sides of a longitudinal axis  124 ,  FIG. 1 , of the device. The stop ledges  122  are arranged to co-act with corresponding stop ledges  126 ,  FIG. 10 , arranged in the interior of the chassis  64  for limiting the rotation of the drive member  118 . 
         [0053]    Further, according to the invention, the drive member  118  is arranged with a generally radially outwardly directed surface  128 ,  FIG. 12 , preferably arranged with a certain noticeable colour or indicia to be used as an indicator of the state of the device, as will be described. The indicator surface  128  could be arranged with a bright colour, such as bright green or bright orange, or could have certain signs or letters like a check mark or “OK”, just to mention a few feasible indicators. In connection with this surface  128 , the chassis is arranged with an opening or a transparent area  130 ,  FIG. 8 , through which the indicator surface may be visible. Also the housing part  60  is arranged with an opening or a transparent area  132 ,  FIG. 6 , where the indicator surface  128  may be viewed. The opening  132  may further be arranged with a magnifying lens so as to increase the visibility of the indicator. 
         [0054]    A spiral drive spring  134 ,  FIG. 13 , is arranged around the drive member  118  and attached with an inner end in an elongated slit  136 ,  FIG. 12 , in the drive member  118  and with the other end in a slit  138  in a spring house  140 ,  FIG. 13 . The spring house  140  is in turn placed inside the distal part of the chassis  64 ,  FIG. 10 , and held fixed in relation to the chassis  64  by longitudinal grooves  142  in the outer surface of the spring house  140  fitting with corresponding ridges  144 . The spring house  140  is held in place in the chassis  64  by a spring house cover  146 ,  FIG. 14 , which is attached to the chassis  64  by proximally directed arms  148  with passages  150 , which accommodate ledges  152  on the outer surface of the chassis  64 . The spring house cover  146  is further arranged with a distally directed tubular member  154 . 
         [0055]    The distal end of the drive member  118  extends into the tubular member  154  of the spring house cover  146 . The distal end of the drive member  64  is arranged with a number of longitudinally extending ledges  156 ,  FIG. 13 . A generally tubular guide member  158 ,  FIG. 13 ,  14 , is further provided, having an end wall  160 . The end wall  160  is arranged with a central passage  162  with a shape corresponding to a cross-section of the distal end of the drive member  64  with the ledges  156 , forming a keying function. The distal end of the drive member  64  with the ledges  156  are further arranged to fit into a corresponding recess  164  on a spring force tensioning member  166 ,  FIG. 15 , such that the spring force tensioning member is operably connected, e.g. rotationally connected, to the drive member. The recess  164  is positioned on a central post  168  inside the spring force tensioning member  166 ,  FIG. 15 . The spring force tensioning member  166  is further arranged with a number of proximally directed arms  170 , which arms  170  are flexible in the generally radial direction. The free ends of the arms  170  are arranged with inwardly extending ledges  172 , which ledges  172  are designed to fit around an annular ledge  174 ,  FIG. 14 , arranged on the circumference of the tubular member  154 . A spring  176 ,  FIG. 16 , is further arranged between the end wall  160  of the guide member  158  and an interior, proximally directed wall of the spring force tensioning member  166 , urging the latter in the distal direction. 
         [0056]    Further, an activation mechanism  178 ,  FIG. 17 , is arranged in the device. It comprises an activation button  180  extending through an opening of one of the housing parts  60 . The activation button  180  comprises two inwardly extending arms,  182 , one on each side of the longitudinal direction  124  of the device. Each arm  182  is arranged with a first surface  184  facing in the proximal direction. The first surface  184  transitions into a second surface  186 , inclined with respect to the first surface  184 . The second surface  186  thereafter transitions into a third surface  188  generally parallel with the first surface  184 . 
         [0057]    The arms  182  are in contact with a dose activator  190 ,  FIG. 11 , comprising a ring-shaped body  192 ,  FIG. 11 , surrounding a part of the drive member extension  76 . The ring-shaped body  192  is arranged with two elongated posts  194 , extending in the longitudinal direction of the device. Each post is arranged with a groove  196 , in which grooves the arms  182  of the activation button  180  fit,  FIG. 17 . 
         [0058]    A distally directed end surface of the ring-shaped body  192  is arranged with a number of circumferentially directed stop ledges  198 ,  FIG. 11 , the function of which will be described below. The stop ledges  198  are to interact with stop ledges  200  on an outer surface of the drive member extension  76 . A compression spring  202 ,  FIG. 13 , is arranged between an interior surface of the activation button  180  and an outer side surface of the chassis  64  for urging the activation button  180  towards an extended position. Further a second compression spring  204 ,  FIG. 8 , is arranged between a proximally directed end surface of the ring-shaped body  192  of the dose activator  190  and a distally directed surface of the transversal wall  66  for urging the ring-shaped body  192  in the distal direction and in engagement between the stop ledges  198  of the ring-shaped body  192  and the stop ledges  200  of the drive member extension  76 . 
         [0059]    The device is intended to function as follows. An appropriate medicament container  26  is placed in the medicament container holder  24  together with the medicament container guide member  40  such that its arms snap in engagement with the medicament holder. The medicament holder is then inserted into the proximal housing part  16 . Then the medicament holder locking member  50  is pushed in engagement with the medicament container guide member  40 . The proximal housing part  12  is then connected to the distal housing part  14  and the chassis  64  via the attachment means  70 ,  72 . The distal end of the medicament container guide member  40  is designed such that it engages the outer surface of the nut lock member  100 , whereby the tongues  106  are pressed radially inwards such that the teeth  108  of the tongues  106  engage the teeth  110  of the guide nut  94 , whereby the guide nut  94  becomes rotationally locked. 
         [0060]    When a dose is to be set and delivered the spring force tensioning member  166  is operated, e.g. rotated. In order to connect the spring force tensioning member  166  to the dose setting mechanism, the spring force tensioning member  166  is pushed in the proximal direction against the force of the spring  176 . The spring force tensioning member  166  and the drive member  118  are then connected in that the ledges  156  fit into the recess  164 . Thus, when the spring force tensioning member  166  is rotated, the drive member  118  is also rotated. The rotation of the drive member  118  causes the spiral drive spring  134  to be tensioned from an initial state where it was pre-tensioned during manufacture of the device. 
         [0061]    During rotation, the flexible arms  116  of the drive member  118  move out of contact with the stop ledges  114  of the ring-shaped member  112  of the drive member extension  64  until they are moved in contact with subsequent stop ledges  114 . The drive member  118  is prevented from being rotated back because the contact of the flexible arms  116  with the stop ledges  114 . 
         [0062]    Further, the drive member extension  64  is in turn prevented from rotating because the stop ledges  198  of the dose activator  192  are in contact with the stop ledges  200  on the drive member extension  64 . 
         [0063]    The spring force tensioning member  166  is rotated until the stop ledge  122  of the drive member  118  comes in contact with the corresponding stop ledge  126  of the chassis  64 . This ensures that the user cannot turn the spring force tensioning member  166  beyond a pre-set position. Therefore a too large dose cannot be set. Now that a dose is set the device is ready for use. A positive feed-back to the user that the device is ready is shown in the opening or window  132  of the device because the turning of the drive member has positioned the indication surface  128  in line with the opening or window  132  of the device. The user is then able to notice the colour or symbol that is an indication that the device is ready for use. 
         [0064]    The user may now position the medicament delivery device at the delivery site and may manually activate the medicament delivery device by pressing the activation button  180  into the device against the force of the return spring  202 . The movement of the activation button  180  causes the arms  182  to slide in the grooves  196  of the posts  194 . After a certain movement, the inclined second surface  186  is moved in contact with a distally directed surface of the groove  196  and thereafter the third surface  188 ,  FIG. 18 . This contact of the second and third surfaces forces the ring-shaped body  192  in the proximal direction. This in turn causes the stop ledges  198  of the dose activator  190  to move out of contact with the stop ledges  200  of the drive member extension  64 . The drive member extension  64  and thereby the drive member  118 , because of the connection between the flexible arms  116  and the stop ledges  114 , are now free to rotate by the force of the spring  134 , and due to the splines connection between the drive member extension  64  and the drive nut  82 , the latter is also rotated. 
         [0065]    Due to the rotation of the drive nut  82 , which is in threaded engagement with the threads  86  of the plunger rod  74 , and because of the rotational lock of the plunger rod with the guide nut  94 , the plunger rod  74  is axially advanced, which causes it to move the stopper  36  inside the medicament container  26  and to force the medicament through the medicament delivery member, e.g. the nebulizing nozzle  38  and the mouth-piece  20 . 
         [0066]    It is to be understood that the embodiment described above and shown in the drawings is to be regarded only as a non-limiting example of the invention and that it may be modified in many ways within the scope of the patent claims.