Patent Publication Number: US-2021178057-A1

Title: Drug delivery device

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/573,097, filed on Sep. 17, 2019, which is a continuation of U.S. patent application Ser. No. 15/208,330, filed on Jul. 12, 2016, now U.S. Pat. No. 10,478,552, issued on Nov. 19, 2019, which is a continuation of U.S. patent application Ser. No. 13/698,894, filed on Nov. 19, 2012, now U.S. Pat. No. 9,408,985, issued on Aug. 9, 2016, which is the U.S. national stage of International Application No. PCT/US11/30182, filed on Mar. 28, 2011, which claims priority to U.S. Provisional Application No. 61/346,542, filed on May 20, 2010, the disclosures of all of which are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to drug delivery devices for parenteral administration of medicament. 
     BACKGROUND OF THE INVENTION 
     Drug delivery devices in the form of infusers are known in the prior art for administering medicament to a patient. Infusers are intended for mounting onto a patient&#39;s skin for self-administration of a medicament. Activation of the infuser not only provides for injection of a needle into a patient&#39;s skin, but also to cause auto-drive of a plunger to drive medicament into the patient via the injected needle. Typical infuser constructions have the needle fixed to the reservoir. For example, with reference to U.S. Pat. No. 5,858,001 to Tsals et al., an infuser is disclosed which is activated through swivel displacement of a reservoir-containing body. A needle is attached to the Tsals et al. device which is also caused to penetrate the skin of a patient with the swivel displacement of the body. The needle is fixed to the body so as to move therewith. Other types of infusers are known, including those which use standard needle-mounted syringe barrels. With infusers, the ability to independently control the injection of the needle, from the administration of medicament, is limited. 
     SUMMARY OF THE INVENTION 
     The subject invention provides a drug delivery device for injecting medicament which includes: a tubular reservoir for accommodating a medicament; a stopper slidably disposed in the reservoir; a spring for moving the stopper from a first position to a second position in the reservoir; at least one needle, the needle having a distal end for insertion into a patient, and a lumen extending proximally from the distal end, the lumen being in direct or indirect communication with the reservoir; a needle driver for displacing the needle from a first state to a second state; and, an actuator. Activation of the actuator causes the spring to move the stopper from the first position and towards the second position, and the needle driver to displace the needle from the first state and towards the second state. The needle moves relative to, and separately from, the reservoir with the needle being displaced from the first state and towards the second state. Advantageously, with the subject invention, a drug delivery device is provided wherein a needle is moved, relative to the reservoir, in being displaced for injection. This permits control of the needle displacement separate from the reservoir. 
     As used herein, the term “distal”, and derivatives thereof, refers to a direction towards a patient during use. The term “proximal”, and derivatives thereof, refers to a direction away from a patient during use. 
     These and other features will be better understood through a study of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a drug delivery device formed in accordance with the subject invention; 
         FIG. 2  is a perspective view of a drug delivery device formed in accordance with the subject invention with internal components being shown; 
         FIG. 3  is a rear perspective view of a drug delivery device formed in accordance with the subject invention; 
         FIGS. 4-14  show different states of a needle driver useable with the subject invention; 
         FIGS. 15-19  show different configurations of a drug delivery device formed in accordance with the subject invention; 
         FIGS. 20 and 21  show an actuator arrangement useable with the subject invention; 
         FIGS. 22-23  show different sealing arrangements useable with the subject invention; 
         FIGS. 24-26  show a sealing arrangement with a secondary needle useable with the subject invention; 
         FIGS. 27-28  show a method of loading a drug delivery device formed in accordance with the subject invention; 
         FIGS. 29-33  show an alternative method of loading a drug delivery device formed in accordance with the subject invention; 
         FIGS. 34-36 and 40  show an end-of-dose indicator useable with the subject invention; 
         FIGS. 37-39  show a mechanism for achieving needle retraction useable with the subject invention; 
         FIGS. 41-43  show a button-releaseable mechanism for needle retraction useable with the subject invention; 
         FIG. 44  is a rear perspective view showing a drug delivery device during use formed in accordance with the subject invention; and, 
         FIGS. 45-47  show a safety pen and needle shield useable with the subject invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the Figures, a drug delivery device is shown and designated with the reference numeral  10 . The drug delivery device  10  generally includes a body  12  accommodating a reservoir  14 , at least one needle  16 , a needle driver  18 , and an actuator  20 . The drug delivery device  10  is for injecting drugs or medicament, these terms being used interchangeably herein, into a patient and is particularly well-suited to be mounted onto a patient&#39;s skin for self-administration, as discussed below. Any form of medicament, e.g., liquid or slurry, including one or more pharmaceutically-active agents, may be administered by the drug delivery device  10 , as will be recognized by those skilled in the art. 
     The body  12  includes a shell  22  encompassing a closed volume  24 . The closed volume  24  is preferably sized and configured to accommodate the working components of the infuser  10  so as to be wholly contained therewithin. The shell  22  is preferably formed of a thermoplastic, but may be formed of other polymeric and/or metallic materials. To ease manufacturing, the shell  22  may be formed of one or more components which snap, or are otherwise assembled, together. One or more openings may be formed in the shell  22  for different purposes. For example, one or more windows  26  may be provided positioned to permit visual observation of the reservoir  14 . In addition, one or more access openings  28  may be provided to permit access to a component, such as the actuator  20 . The shell  22  may also include one or more removable panels  30 , which also permit access to the interior of the shell  22 , such as to permit filling of the reservoir  14 . 
     The body  12  may be of various shapes. As shown in the Figures, the body  12  may have a generally rectangular box shape. Other shapes are possible. It is preferred that the body  12  include a generally flat skin mounting surface  32  on which preferably is disposed adhesive  34 . The adhesive  34  may be of any type which permits mounting of the infuser  10  to a patient&#39;s skin for use and later removal thereof. The adhesive  34  may be a low tack pressure sensitive adhesive, but other forms may also be useable. An access opening  28 ′ is formed to extend through the shell  22  at the skin mounting surface  32  and is formed to permit passage therethrough of the needle  16 , as described below. Preferably, the adhesive  34  bounds the needle access opening  28 ′. 
     The reservoir  14  is preferably a tubular barrel. The reservoir  14  is preferably of a circular cross-section, but may be of other cross-sectional shapes. In addition, it is preferred that the reservoir  14  be formed of glass, but may be also formed of a polymeric material. With a tubular configuration, the reservoir  14  includes a wall  36  extending between first and second ends  38 ,  40  with a lumen  42  extending therebetween. A stopper  44  is slidably disposed in the reservoir  14  particularly in sealing engagement with the wall  36  within the lumen  42 . The stopper  44  is preferably of an elastomeric material and is formed in any manner known in the art. 
     The at least one needle  16  is mounted to the needle driver  18 . Reference herein shall be to the use of a single needle, but, as will be recognized by those skilled in the art, a plurality of needles may be likewise utilized. The needle driver  18  is configured to displace the needle  16  from a first state to a second state. The first state may coincide with the needle  14 , more particularly a distal end  46  of the needle  14 , being contained within the body  12  ( FIG. 4 ). The second state may coincide with the distal end  46  of the needle  16  being exposed externally of the body  12  to be in an injection position ( FIG. 6 ). The needle  16  and the distal end  46  may be formed in any known manner for injecting into a patient. 
     The needle  16  includes a lumen  48  which extends proximally from the distal end  46 . The lumen  48  is in direct or indirect communication with the reservoir  14 . With direct communication, an open passage is defined between the reservoir  14  and the lumen  48 . More preferably, a breachable seal arrangement or adjustable valve is in the flowpath between the reservoir  14  and the lumen  48  so as to permit selective communication therebetween. With this arrangement, inadvertent flow from the reservoir  14  and through the lumen  48  may be minimized, particularly during transportation and storage. 
     In a preferred arrangement, a flow channel  50  extends from the lumen  48  and through the needle driver  18  into communication with the reservoir  14 . In a preferred arrangement, the needle driver  18  is in the form of a deformable cantilevered arm having a fixed end  52  and a free end  54 . The needle  16  is fixed at or near the free end  54  using any known technique. Preferably, the needle driver  18  is formed of thermoplastic, with the needle  16  being formed of a metallic material. The needle  16  may be adhered and/or molded into the needle driver  18 . The flow channel  50  is defined to extend through the needle driver  18  into communication with the lumen  48 . 
     The needle driver  18  may be of various configurations which achieve displacement of the needle  16 . The needle driver  18  is caused to displace under motive force which may be generated from internal resilience of the needle driver  18  or applied from an external source, such as a spring or other force applicator. With reference to  FIG. 4 , it is preferred that the needle driver  18  be in a flat, unbiased state prior to use. In this manner, plastic deformation of the needle driver  18  into an undesired state may be avoided. It is possible to have the free end  54  of the needle driver  18  held in a deflected state, where internal resilience of the needle driver  18  may provide spring force for displacing the needle  16 . Any form of retaining mechanism may be used to releasably retain the needle driver  18  in the deflected state. However, maintenance of the needle driver  18  in the deflected state may result in plastic deformation thereof with little or no spring back upon release of the retaining mechanism. Although the needle driver  18  may be configured to overcome the situation through material choice, it is preferred that the needle driver  18  be formed generally flat so as to not provide a deflected, or otherwise deformed, state. 
     The drug delivery device  10  is configured, such that upon activation, medicament is caused to be auto-driven from the reservoir  14  and, separately, the needle  16  is caused to be displaced so as to be inserted into a patient. It is preferred that a single actuation of the actuator  20  be utilized to achieve such dual effect. Various actuator configurations may be utilized. By way of non-limiting example, the actuator  20  may be of a displaceable button-type which is configured for linear displacement. As will be appreciated by those skilled in the art, other actuators may be utilized. 
     A spring  58  is provided for moving the stopper  44  from a first position to a second position in the reservoir  14 . Movement of the stopper  44  causes displacement of the medicament from the reservoir  14 . In an initial, pre-use state, a retaining arrangement is provided to retain the stopper  44  in the first position against force of the spring  58 . Upon actuation of the actuator  20 , the retaining arrangement is released, thus permitting movement of the stopper  44  to the second position. Simultaneously, actuation of the actuator  20  results in the needle driver  18  displacing the needle  16  so as to inject a patient. Medicament, under force of movement of the stopper  44 , is caused to flow through the needle  16  so as to be administered to a patient. 
     The actuation of the needle driver  18  may be achieved in various manners. In a preferred embodiment, an elongated, trough-shaped needle actuator  60  may be provided coextensive with at least a portion of the needle driver  18 . One or more detents  62  extend from the needle driver  18  to ride along tracks or other features formed in the needle actuator  60 . In a preferred arrangement, the needle actuator  60  is caused to be linearly displaced relative to the needle driver  18  causing the detents  62  to travel along the features of the needle actuator  60 . This interaction results in displacement of the needle  16 . 
     In a preferred embodiment, two sets of the detents  62  are provided, namely a spring set of detents  62   a  and a release set of detents  62   b . The release detents  62   b  are located at or near the free end  54  of the needle driver  18 . The spring detents  62   a  are located at a mid-location of the needle driver  18  between the fixed end  52  and the free end  54 . It is preferred that the spring detents  62   a  and the release detents  62   b  be shaped and configured so as to provide a collective acting force that is evenly applied to the needle driver  18 . Generation of moment about longitudinal axis  64  is undesired. 
     As shown in  FIGS. 4 and 12 , and discussed above, the needle driver  18  is preferably initially in a generally flat state prior to use. With actuation of the actuator  20 , the needle actuator  60  is caused to be displaced relative to the needle driver  18  such that ramped surfaces  66  cause downward deflection of the spring detents  62   a , as shown in  FIG. 13 . In this state, the release detents  62   b  are in engagement with stop surfaces  68 . Due to the interengagement between the release detents  62   b  and the stop surfaces  68 , deflection of the free end  54  is restrained. With sufficient movement of the needle actuator  60  relative to the needle driver  18 , the release detents  62   b  are caused to come clear of the stop surfaces  68 . The displacement of the spring detents  62   a  generates a spring force in the needle driver  18  which causes the free end  54  to be urged to return to its natural, flat state with the free end  54  being displaced downwardly ( FIG. 14 ). This successive set of actions results in the needle  16  being displaced from the first state, shown in  FIG. 12 , to the second state, shown in  FIG. 14 . As discussed above, in the first state, the needle  16 , particularly the distal end  46 , is within the enclosed volume  24 , while in the second state, the distal end  46  is exposed externally of the shell  22 . The displacement of the needle  16  is utilized to cause the needle  16  to penetrate the skin of a patient for injection. 
     Once displaced, the needle driver  18  seeks to regain its initial flat configuration through inherent memory of its constituent material. As shown in  FIG. 14 , interengagement between the ramped surfaces  66  and the spring detents  62   a  maintains the needle  16  in the second state, penetrated in a patient. 
     As will be appreciated by those skilled in the art, other arrangements for causing displacement of the needle  16  may be utilized. For example, a releasable spring arrangement may be utilized, whereby the needle driver  18  is retained in the first state against spring force, with release of a retaining arrangement permitting the spring force to displace the needle driver  18  to the second state. Spring force may be supplied by various springs, such as compression springs, coil springs, elastomeric members, gas compression springs, and so forth. 
     Movement of the needle actuator  60  relative to the needle driver  18  may be provided by various configurations. Preferably, a needle actuator spring  70  is provided to act against the needle actuator  60  to cause displacement thereof. 
     Various retaining arrangements may be provided for retaining the needle actuator  60  in a first state against force of the needle actuator spring  70 , prior to use, as shown in  FIG. 4 . Preferably, the retaining arrangement is caused to be released with actuation of the actuator  20 . By way of non-limiting example, and with reference to  FIGS. 4-6 , the retaining arrangement may include a boss  72  which extends from the needle actuator  60  to be engaged by the actuator  20 . A locking channel  74  is defined in the boss  72  in which is seated a locking flange  76  in an initial, pre-use state. With displacement of the actuator  20  upon actuation, the locking flange  76  is caused to come out of engagement with the locking channel  74 , as shown in  FIG. 5 . The locking flange  76  may be defined by a portion of the actuator  20 . The needle actuator  60  is then caused to be displaced under force of the needle actuator spring  70 . 
     The travel of the needle actuator  60  may be limited with interengagement of a stop or similar member. A clearance opening  78  ( FIG. 2 ) is formed in the needle actuator  60  through which the needle  16  passes upon displacement. The clearance opening  78  is in at least partial registration with the needle access opening  28 ′ during displacement of the needle  16  to permit the needle  16  to achieve injection into a patient ( FIG. 44 ). The needle access opening  28 ′ is sized and configured to not interfere with the needle  16  during injection. 
     The clearance opening  78  may be configured to limit displacement of the needle driver  18  during actuation. In particular, the clearance opening  78  may be configured to permit passage therethrough of the needle  16  but not the needle driver  18 . As such, interengagement between the needle driver  18  and portions of the needle actuator  60  adjacent to the clearance opening  78  acts as a limit on displacement of the needle driver  18 . This defines the second state of the needle driver  18  and may define the depth of injection of the needle  16 . Alternatively, the clearance opening  78  may be configured to not interferingly engage with the needle driver  18 . In this manner, the patient&#39;s skin acts as a stop for the needle driver  18 . 
     With respect to movement of the stopper  44 , a retaining arrangement may be provided to restrain movement of the stopper  44  against force of the spring  58  in an initial, pre-use state. By way of non-limiting example, and with reference to  FIGS. 20 and 21 , a plunger  80  may be provided which is in engagement with the stopper  44  and formed to extend to be engageable by the actuator  20 . A plunger locking channel  82  may be formed in the plunger  80 , and a plunger locking flange  84  may be provided formed to seat in the plunger locking channel  82  in an initial, pre-use state. With displacement of the actuator  20 , upon actuation, the plunger locking flange  84  is displaced so as to disengage from the plunger locking channel  82 , thereby permitting displacement of the stopper  44  under force of movement of the spring  58 . The plunger locking flange  84  may be defined by a portion of the actuator  20 . As will be appreciated by those skilled in the art, a single actuation of the actuator  20  may result in release of both the stopper  44  and the needle actuator  60 . For example, with reference to  FIG. 21 , the actuator  20  may define both the locking flange  76  and the plunger locking flange  84  such that displacement of the actuator  20  results in displacement of the locking flange  26  and the plunger locking flange  84  with simultaneous release of both the stopper  44  and the needle actuator  60 . 
     With the drug delivery device  10  intended for use against a patient&#39;s skin, it is preferred that venting of the reservoir  14  or priming of the needle  16  not be required to administer medicament from the reservoir  14 . 
     With the needle  16  being inserted into a patient, and the stopper  44  being caused to move, medicament may be displaced from the reservoir  14  through the flow channel  50  and administered to a patient via the needle  16 , if there is direct communication between the lumen  42  of the needle  16  and the reservoir  14 . As indicated above, it is preferred that a breachable seal arrangement or adjustable valve be utilized to provide indirect communication, with communication being achievable with breach of the seal arrangement and/or adjustment of the valve. 
     In a preferred embodiment, an adjustable valve  86  may be utilized. With reference to  FIG. 22 , the valve  86  includes a valve stem  88  having one or more seal members  90 . In one variation, as shown in  FIG. 22 , the seal members  90  may be configured to seal against a portion of the reservoir  14  in an initial state. In this manner, medicament contained within the reservoir  14  may be contained, during transportation and storage, within the reservoir  14 . It is preferred that the reservoir  14  have a reduced diameter neck portion  92  at the first end  38  which defines exit opening  94 . It is preferred that the valve  86  seal the reservoir  14  so as to contain the medicament wholly therewithin. In this manner, stability of the medicament in the reservoir  14 , particularly during storage, may be better maintained. As indicated above, it is preferred that the reservoir  14  be formed of glass. 
     In a preferred arrangement, as shown in  FIG. 23 , an adaptor  96  may be provided in which the first end  38  of the reservoir  14  is seated. The first end  38  of the reservoir  14  may be formed in the same manner as a standard syringe tip, e.g., a Luer tip. A flow space  98  is provided in the adaptor  96  adjacent to, and in communication with, the reservoir  14 . The seal members  90  are configured in this arrangement so as to seal the flow space  98  so as to prevent flow therefrom. With this arrangement, however, medicament may be in contact with portions of the adaptor  96 , particularly portions of the adaptor  96  about the flow space  98  prior to use (e.g., during shipping and storage). The adaptor  96  may be formed of plastic or other polymeric material. Choice of materials for the valve  86  and the adaptor  96  should be considered in view of the medicament being stored in the reservoir  14 . 
     To achieve flow from the reservoir  14 , the valve  86  is made adjustable so as to adjust from a sealed, pre-use state, to an open, in-use state use. With reference to  FIG. 22 , in the alternative embodiment, the neck portion  92  preferably includes an inwardly extending lip  100  defined about the exit opening  94 . In the initial state, as shown in  FIG. 22 , the seal members  90  seal against the lip  100  so as to seal the flow space  98  from the reservoir  14 . To achieve the open state, the valve  86  is displaced such that the valve stem  88  shifts into the reservoir  14  with the seal members  90  coming out of sealing engagement with the lip  100 . As such, a flow path is thus defined about the valve stem  88  and through the exit opening  94 . The flow channel  50  may, thus, come into communication with the flow space  98 . With the valve  86  being in the open state, and with the stopper  44  being caused to move, medicament is urged from the reservoir  14  through the exit opening  94 , into the flow space  98 , and into the flow channel  50  for administration to a patient. To provide sealing of the flow space  98 , the adaptor  96  may be provided with a raised sealing ring  102  which comes into close contact with the valve stem  88 . In addition, or alternatively, secondary seal members  104  may be provided on the valve  86  formed to define a seal with portions of the adaptor  96  to further restrict flow thereby. 
     In the preferred embodiment, shown in  FIG. 23 , the valve  86  may be adapted to form a seal in similar manner, here having the seal members  90  engage against and form a seal with the sealing ring  102  of the adaptor  96 . Adjustment of the valve  86  towards the reservoir  14  causes disengagement of the seal members  90  from the sealing ring  102  to permit flow thereby. The flow channel  50  may be in communication with a secondary flow space  116 , and the sealing ring  102  may be positioned between the secondary flow space  116  and the flow space  98 . The secondary seal members  104  are provided to seal the secondary flow space  116  and prevent inadvertent flow therefrom. 
     Adjustment of the valve  86  may be achieved in various manners. In a preferred embodiment, a pivoting valve rocker  106  may be utilized. As shown in  FIGS. 2 and 8 , the valve rocker  106  is mounted to a pivot pin  108  so as to be pivotable thereabout. A first arm  110  of the valve rocker  106  extends from the pivot pin  108  to be in engagement with the valve  86 . A second arm  112  of the valve rocker  106  extends in an opposing direction from the pivot pin  108  so as to be in engagement with the needle actuator  60 . As shown in  FIG. 9 , the valve rocker  106  is configured to be engaged by the needle actuator  60  upon sufficient movement relative to the needle driver  18 . With sufficient movement of the needle actuator  60 , the second arm  112  is caused to be displaced, resulting in pivoting movement of the valve rocker  106  and corresponding movement of the first arm  110  against the valve  86 . Movement against the valve  86  results in adjustment thereof from the sealed state to the open state. More particularly, movement of the valve  86  results in shifting of the valve stem  88  into or towards the reservoir  14 . 
     As shown in  FIG. 22 , the valve  86  may include a locking ring or tooth  114  for releasably retaining the valve  86  in the sealed state. The locking ring  114  is formed to resiliently release from the adaptor  96  under sufficient force of movement from the valve rocker  106 . The locking ring  114  acts to prevent inadvertent adjustment of the valve  86  prior to use. 
     As will be appreciated by those skilled in the art, the reservoir  14  may be of various configurations. Preferably, a syringe barrel may be used to define the reservoir  14 , particularly where the neck portion  92  is utilized. It is further preferred to use the sealing arrangement of  FIG. 23  where a standard syringe may be utilized without modification. The reservoir  14  may be barrel-shaped with one end being selectively sealed by the valve  86 . Alternatively, as shown in  FIGS. 8-10 and 24-26 , a secondary stopper  118  or a septum  120  may be utilized to seal the first end  38  of the reservoir  14 . Here, the reservoir  14  may be in the form of a drug cartridge with the septum  120  sealing the exit opening  94  being defined in the neck portion  92  ( FIG. 25 ). The septum  120  may be formed of any elastomeric material as is known in the art which permits piercing of therethrough, as described below. Alternatively, the reservoir  14  may include the secondary stopper  118  being located at or near the first end  38 , spaced from the stopper  44  ( FIG. 8 ). The secondary stopper  118  may be disposed in the lumen  48  so as to form a seal against the reservoir  14 , as is known in the art. 
     With the use of the secondary stopper  118  or the septum  120 , access may be provided to the contents of the reservoir  14  through the use of a secondary needle  122  ( FIGS. 24-26 ). The secondary needle  122  includes a first end  124  initially spaced from or partially embedded into the secondary stopper  118  or the septum  120 . With relative movement between the secondary needle  122  and the reservoir  14 , the first end  124  of the secondary needle  122  is caused to pierce through the secondary stopper  118  or the septum  120  so as to obtain access to the contents within the reservoir  14 . Any mode of obtaining relative motion may be utilized. In a preferred arrangement, with the reservoir  14  being sealed by the secondary stopper  118  or the septum  120 , the reservoir  14  may be caused to move under force of action of the spring  58  prior to the first end  124  of the secondary needle  122  piercing through the secondary stopper  118  or the septum  120 . In a fully sealed state, and with the medicament being a liquid or a slurry, the medicament is generally incompressible with force being transmitted therethrough to allow for movement of the entire reservoir  14 . With the secondary needle  122  accessing the contents of the reservoir  14 , the further force applied to the stopper  44  by the spring  58  results in the medicament being urged into lumen  126  of the secondary needle  122  for administration to a patient. The secondary needle  122  is formed with a second end  127  in communication with the flow channel  50 . 
     To limit inadvertent movement of the reservoir  14 , one or more locking fingers  128  may extend from the shell  22  or other surrounding components to interferingly engage the reservoir  14  in limiting movement thereof. With sufficient force being applied to the reservoir  14 , the one or more locking fingers  128  may be caused to deform or be displaced so as to permit movement of the reservoir  14 . The secondary needle  122  may be fixed to the shell  22  in any known manner. In addition, the secondary needle  122  may be bent or otherwise configured so as to permit the lumen  126  to come into contact with the flow channel  50 . 
     With the use of the secondary needle  122 , the second end  127  may be formed to extend into the needle driver  18  with the lumen  126  in communication with the flow channel  50  ( FIG. 24 ). With actuation of the needle driver  18 , the needle driver  18  may rotate about the secondary needle  122  while maintaining communication therewith. If the secondary needle  122  is not utilized, the driver  18  may be provided with an extension  17  through which the flow channel  50  extends into communication with the reservoir  14  (directly or indirectly) ( FIG. 2 ). 
     The drug delivery device  10  may be pre-assembled and stored with medicament in the reservoir  14  prior to shipping and storage. With reference to  FIGS. 27 and 28 , the drug delivery device  10  may be prepared with the reservoir  14  being in a partially assembled state within the shell  22  and filled in this state. Thus, as shown in  FIGS. 27 and 28 , the reservoir  14  may be filled through the second end  40  through one of the access openings  28 . Once filled, the stopper  44  may be inserted into the lumen  48  of the reservoir  14  to seal the reservoir  14  and the drug delivery device  10  may be fully assembled. With reference to  FIG. 15 , the reservoir  14  may be pre-assembled and pre-filled with medicament and then mounted to the shell  22  with one of the access openings  28 . To ease manufacturing, one or more components of the drug delivery device  10  may be formed as a module, such as, for example, the plunger  80  may be provided together with the spring  58  and the actuator  20 . Module housing  130  may be provided to accommodate the components in an assembled state. 
     In an alternative arrangement, and with reference to  FIGS. 29-33 , the reservoir  14  may be maintained separately from the drug delivery device  10  prior to use. For example, the reservoir  14  may be in the form of a drug cartridge. As shown in  FIG. 29 , the window  26  may be shaped and configured so as to permit the reservoir  14  to be passed therethrough into position within the shell  22 . This motion is similar to the insertion of a battery into an appliance. One or more snap retaining members  132  may be provided to engage the reservoir  14  to provide retention therefor in a desired position. In the desired position, the stopper  44  is positioned to align with the plunger  80  and the exit opening  94  is positioned to align with the secondary needle  122  so as to permit piercing thereof. The reservoir  14  may be in the form of a constant-diameter barrel having the stopper  44  and the septum  120  with the reservoir  14  being insertable through the window  26  in the same manner as described above with the reservoir  14  being in the form of a drug cartridge. 
     As will be appreciated by those skilled in the art, the drug delivery device  10  may include additional features beyond those described above. For example, it may be desired to provide for retraction of the needle  16  post-use. The needle  16  may be caused to retract in various manners. With reference to  FIGS. 37-39 , in one approach, the needle actuator  60  is caused to move in a reverse direction relative to the needle driver  18 , this direction being opposite to the original direction of movement used to cause displacement of the needle  16 . By way of non-limiting example, as shown in  FIGS. 37-39 , a drive spring  134  may be disposed within the plunger  80 , which is disposed to act against secondary plunger  136 . The secondary plunger  136  is held in an initial position due to interengagement with latch  138 . With the stopper  44  reaching the end of its full travel, the latch  138  is caused to be released with the secondary plunger  136  being driven forwardly under force of the drive spring  134 . The secondary plunger  136  is caused to engage against the valve  86 , applying force thereto so as to shift the valve  86  to return towards its initial state. The valve  86 , thus, acts against the valve rocker  106  with resulting reverse pivoting movement towards its original state. In response, the valve rocker  106  acts against the needle actuator  60  so as to urge the needle actuator  60  to its original state. With movement of the needle actuator  60  to its original state, displacement of the needle driver  18  is reversed and the needle  16  is caused to retract. 
     In a preferred embodiment, as shown in  FIGS. 41-43 , the first arm  110  of the valve rocker  106  may be bent or otherwise configured to define a stop  140 , positioned to engage the needle actuator  60  upon a predetermined extent of movement relative to the needle driver  18 . The stop  140  is positioned to allow sufficient movement of the needle actuator  60  to permit the needle  16  to be displaced for injection. A secondary actuator  142 , which is preferably in the form of a linearly displaceable button, is positioned to press against the stop  140  to cause disengagement from the needle actuator  60 . With disengagement, the needle actuator  60  is free to further travel under force of the needle actuator spring  70  ( FIG. 42 ). Secondary ramp surfaces  144  are positioned to engage against the release detents  62   b  so as to cause retraction of the needle  16  into the shell  22  ( FIG. 7 ). Furthermore, as shown in  FIG. 40 , this movement of the needle actuator  60  causes the clearance opening  78  to come out of alignment with the needle access opening  28 ′, thus further limiting access to the needle  16 . 
     The drug delivery device  10  may be also provided with an end-of-dose indicator to provide a sensory indication that a dose has been completely administered. With reference to  FIGS. 34-36 and 40 , the plunger  80  may be provided with an indicator sleeve  146  that is formed to extend through the stopper  44  in an initial state. The indicator sleeve  146  includes a ridge  148 . The plunger  80  is provided with outwardly displaceable engagement members  150  located to restrict movement of the indicator sleeve  146  away from the stopper  44 . With the plunger  80  being moved by the spring  58  to urge medicament from the reservoir  14 , the stopper  44  eventually comes to an end-of-travel with engagement against a portion of the reservoir  14  and/or against the secondary stopper  118 . This position will coincide with the end of the dosing stroke. As shown in  FIG. 36 , the indicator sleeve  146  will be engaged by a portion of the reservoir  14  and/or the secondary stopper  118  prior to engagement by the stopper  44 . Further force applied to the stopper  44  by the plunger  80  causes displacement of the engagement members  150  over the ridge  148 . The plunger  80  is provided with one or more indicator windows  152 . In the initial state, the indicator sleeve  146  is out of alignment with the indicator windows  152 . Upon being displaced at the end of the dosing stroke, a portion of the indicator sleeve  146  comes into alignment with the one or more indicator windows  152  so as to be visually observable from outside the plunger  80  ( FIG. 40 ). One or more of the windows  26  in the shell  22  may be aligned so as to permit observation of the indicator sleeve  146  through the indicator windows  152 . Preferably, the indicator sleeve  146  is formed of a different color from the plunger  80  so as to be readily discernable. It is also noted that the surmounting of the ridge  148  by the engagement members  150  may also provide a tactile and/or audible indication of end-of-dose administration. 
     With reference to  FIG. 3 , it is also noted that a needle shield  154  may be provided to cover the needle access opening  28 ′ prior to use. The needle shield  154  may be secured, such as by friction fit into the needle access opening  28 ′. A finger tab  156  may be provided to extend from the needle shield  154 , particularly beyond the perimeter of the shell  22  to ease removal of the needle shield  154 . 
     A safety pin  158  may also be provided and formed to coact with the actuator  20  so as to prevent inadvertent actuation thereof. With reference to  FIGS. 45-47 , the safety pin  158  may be formed to extend into the actuator  20  so as to prevent displacement thereof. The safety pin  158  is required to be removed so as to permit actuation of the actuator  56 . The safety pin  158  may be formed unitarily with the needle shield  154  such that with single removal of the needle shield  154 /the safety pin  158  assembly, the drug delivery device  10  may be readied for use.