Patent Publication Number: US-10322239-B2

Title: Medicament delivery device for administration of opioid antagonists including formulations for naloxone

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/605,512, entitled “Medicament Delivery Device for Administration of Opioid Antagonists Including Formulations for Naloxone,” filed Jan. 26, 2015, which is a continuation of U.S. patent application Ser. No. 14/062,516, now U.S. Pat. No. 8,939,943, entitled “Medicament Delivery Device for Administration of Opioid Antagonists Including Formulations for Naloxone,” filed Oct. 24, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 13/357,935, now U.S. Pat. No. 9,084,849, entitled “Medicament Delivery Devices for Administration of a Medicament within a Prefilled Syringe,” filed Jan. 25, 2012, which claims priority to U.S. Provisional Patent Application No. 61/436,301, entitled “Devices and Methods for Delivering Lyophilized Medicaments,” filed Jan. 26, 2011, the disclosure of each of which is hereby incorporated by reference in its entirety. U.S. patent application Ser. No. 14/062,516 is also a continuation-in-part of U.S. patent application Ser. No. 13/036,720, now U.S. Pat. No. 8,627,816, entitled “Medicament Delivery Device for Administration of Opioid Antagonists Including Formulations for Naloxone,” filed Feb. 28, 2011, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The embodiments described herein relate generally to medical device and pharmaceutical compositions, and more particularly to a medicament delivery device for administration of opioid antagonists, including formulations for naloxone. 
     Naloxone is a medicament that prevents and/or reverses the effects of opioids. Known formulations of naloxone can be used, for example, to treat respiratory depression and other indications that result from opioid toxicity. For example, known formulations for naloxone can be used to reverse and/or mitigate the effects of an overdose of a drug containing opioids, such as, for example, heroin. In such situations, it is desirable to deliver the naloxone formulation quickly and in a manner that will produce a rapid onset of action. Accordingly, known formulations of naloxone are often delivered either intranasally or via injection. 
     The delivery of naloxone intranasally or via injection, however, often involves completing a series of operations that, if not done properly, can limit the effectiveness of the naloxone formulation. For example, prior to delivering the naloxone, the user must first determine whether the patient&#39;s symptoms warrant the delivery of naloxone, and then couple a needle (or an atomizer) to a syringe containing the naloxone formulation. After the device is prepared for delivery, the user then selects the region of the body in which the naloxone is to be delivered, and manually produces a force to deliver the naloxone. In some situations, such as, for example, when the patient is in an ambulance or a hospital setting, the user then inserts an intravenous catheter to administer the naloxone. Additionally, after the delivery of the naloxone formulation, the user must dispose of the device properly (e.g., to prevent needle sticks in instances where the naloxone is injected) and seek further medical attention for the patient. Accordingly, known formulations of naloxone are often delivered by a healthcare provider in a controlled environment (e.g. a hospital, physician&#39;s office, clinic or the like). Access to emergency medical facilities and/or trained health care providers, however, is not always available when an individual is suffering from an overdose. Moreover, because naloxone is often administered during an emergency situation, even experienced and/or trained users may be subject to confusion and/or panic, thereby compromising the delivery of the naloxone formulation. 
     Known devices for delivering naloxone also require that the user manually generate the force and/or pressure required to convey the naloxone from the device into the body. For example, to deliver naloxone using known syringes, the user manually depresses a plunger into the syringe body. The force generated by manually depressing a plunger, however, can be sporadic, thus resulting in undesirable fluctuations in the flow of the naloxone and/or incomplete delivery of the full dose. Such fluctuations and variability can be particularly undesirable when the naloxone is being atomized for intranasal delivery. Moreover, in certain situations, the user may be unable to generate sufficient force to provide the desired flow rate and/or flow characteristics (e.g., for an atomizer) of the naloxone. 
     Additionally, because naloxone is often delivered by a healthcare provider in a controlled environment, known formulations of naloxone are generally stored under controlled conditions, and for limited periods of time. For example, known naloxone formulations are often formulated to be stored between 20 and 25 degrees Celsius. Accordingly, known naloxone formulations are not compatible for being carried by a patient or a third party (e.g., a relative of friend of the patient) for long periods of time. 
     Thus, a need exists for improved methods and devices for delivering opioid antagonists, such as, for example, devices that provide for the delivery of naloxone by untrained users. Additionally, a need exists for naloxone formulations that can be exposed to a wide range of environmental conditions for long periods of time. 
     SUMMARY 
     Medicament delivery devices for administration of opioid antagonists and chemical compositions used within such devices are described herein. In some embodiments, a naloxone composition can be formulated for use in a delivery device of the types shown and described herein. The naloxone composition includes an effective amount of naloxone i.e., 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one, or a pharmaceutically acceptable salt and/or ester thereof. As used herein, an “effective amount” is an amount sufficient to provide a desired therapeutic effect. In some embodiments, the naloxone composition can include a pH-adjusting agent, such as, for example, at least one of hydrochloric acid, citric acid, acetic acid, phosphoric acid, or combinations thereof. In some embodiments, the naloxone composition can include one or more tonicity-adjusting agents, such as, for example, at least one of dextrose, glycerin, mannitol, potassium chloride, sodium chloride, or combinations thereof. Because the naloxone composition may be stored in the medicament container of a delivery device for extended periods of time under varying storage conditions, in some embodiments the naloxone composition can include stabilizers to prevent or inhibit decomposition of the naloxone during storage. 
     In some embodiments, an apparatus includes a housing, a medicament container disposed within the housing and an energy storage member disposed within the housing. The medicament container is filled with a naloxone composition that includes naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent, whereby the osmolality of the naloxone composition ranges from about 250-350 mOsm and the pH ranges from about 3-5. The energy storage member is configured to produce a force to deliver the naloxone composition. 
     In some embodiments, the medicament delivery device can further include an elastomeric member disposed within the medicament container that is configured to be compatible with the naloxone composition. Said another way, in some embodiments, an elastomeric member disposed within the medicament container can be formulated to prevent undesired leaching and/or reaction with the naloxone composition. In some embodiments, the elastomeric member is formulated to include a polymer and a curing agent. The polymer includes at least one of bromobutyl or chlorobutyl, and the curing agent includes at least one of sulfur or metal compounds, e.g., metal oxides such as zinc oxide or magnesium oxide, etc. 
     In some embodiments, the medicament delivery device can include an electronic circuit system coupled to the housing. The electronic circuit system is configured to produce an output when the electronic circuit system is actuated. The output can be, for example, an audible or visual output related to the naloxone composition (e.g., an indication of the expiration date, the symptoms requirement treatment with naloxone or the like), the use of the medicament delivery device, and/or post-administration procedures (e.g., a prompt to call 911, instructions for the disposal of the device or the like). 
     In some embodiments, an apparatus includes a housing, a medicament container and a movable member. The medicament container is configured to move within the housing between a first position and a second position in response to a force produced by an energy storage member. A proximal end portion of the medicament container includes a flange and has a plunger disposed therein. The movable member is configured to move within the housing. A first shoulder of the movable member is configured to exert the force on the flange to move the medicament container from the first position to the second position. A portion of the first shoulder is configured to deform when the medicament container is in the second position such that at least a portion of the force is exerted upon the plunger. A second shoulder of the movable member is configured to exert a retraction force on the flange to move the medicament container from the second position towards the first position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-4  are schematic illustrations of a medicament delivery device according to an embodiment, in a first, second, third and fourth configuration, respectively. 
         FIGS. 5-8  are schematic illustrations of a medicament delivery device according to an embodiment, in a first, second, third and fourth configuration, respectively. 
         FIGS. 9 and 10  are perspective views of a medical injector according to an embodiment, in a first configuration. 
         FIG. 11  is a front view of the medical injector illustrated in  FIG. 9  with a cover removed. 
         FIG. 12  is a back view of the medical injector illustrated in  FIG. 9  with the cover removed. 
         FIG. 13  is a front view of a portion of the medical injector illustrated in  FIG. 9 . 
         FIG. 14  is a perspective view of a portion of the medical injector illustrated in  FIG. 9 . 
         FIG. 15  is a bottom perspective view of a housing of the medical injector illustrated in  FIG. 9 . 
         FIG. 16  is a top perspective view of a housing of the medical injector illustrated in  FIG. 9 . 
         FIG. 17  is a perspective view of a proximal cap of the medical injector illustrated in  FIG. 9 . 
         FIGS. 18 and 19  are front views of a medicament delivery mechanism of the medical injector illustrated in  FIG. 9 . 
         FIG. 20  is a perspective view of a portion of the medical injector illustrated in  FIG. 9 . 
         FIG. 21  is an enlarged cross-sectional view of a portion of the medical injector illustrated in  FIG. 9 . 
         FIG. 22  is an exploded view of a medicament container of the medical injector illustrated in  FIG. 9 . 
         FIGS. 23 and 24  are perspective views of a carrier included in the medical injector illustrated in  FIG. 9  in a first configuration. 
         FIG. 25  is a perspective view of the carrier included in the medical injector illustrated in  FIG. 9  in a second configuration. 
         FIG. 26  is a perspective view of a portion of the medical injector illustrated in  FIG. 9 . 
         FIG. 27  is an enlarged front cross-sectional view of the portion of the medical injector illustrated in  FIG. 26 . 
         FIG. 28  is an enlarged side cross-sectional view of the portion of the medical injector illustrated in  FIG. 26 . 
         FIG. 29  is a back view of an electronic circuit system of the medical injector illustrated in  FIG. 9 . 
         FIG. 30  is a front view of a portion of the electronic circuit system of the medical injector illustrated in  FIG. 29 . 
         FIG. 31  is a side view of the electronic circuit system of the medical injector illustrated in  FIG. 29 . 
         FIG. 32  is a front view of an electronic circuit system housing of the electronic circuit system illustrated in  FIG. 29 . 
         FIG. 33  is a perspective view of the electronic circuit system housing of the electronic circuit system illustrated in  FIG. 32 . 
         FIG. 34  is a perspective view of a battery clip of the electronic circuit system illustrated in  FIG. 29 . 
         FIG. 35  is a perspective view of a portion of an electronic circuit system of the medical injector illustrated in  FIG. 9 , in a first configuration. 
         FIG. 36  is a front view of the medical injector illustrated in  FIG. 9  in a first configuration showing the electronic circuit system. 
         FIGS. 37-39  are front views of a portion of the electronic circuit system of the medical injector labeled as Region Z in  FIG. 36  in a first configuration, a second configuration and a third configuration, respectively. 
         FIGS. 40 and 41  are perspective views of a cover of the medical injector illustrated in  FIG. 9 . 
         FIG. 42  is a perspective view of a safety lock of the medical injector illustrated in  FIG. 9 . 
         FIG. 43  is a front view of the safety lock of the medical injector illustrated in  FIG. 42 . 
         FIG. 44  is a bottom view of the safety lock of the medical injector illustrated in  FIG. 42 . 
         FIG. 45  is a cross-sectional view of the safety lock of the medical injector illustrated in  FIG. 42 . 
         FIG. 46  is a perspective view of a needle sheath of the safety lock of the medical injector illustrated in  FIG. 42 . 
         FIG. 47  is a perspective view of a base of the medical injector illustrated in  FIG. 9 . 
         FIG. 48  is a front view of the base of the medical injector illustrated in  FIG. 47 . 
         FIG. 49  is a back view of the medical injector illustrated in  FIG. 9  in a second configuration. 
         FIG. 50  is a back view of the medical injector illustrated in  FIG. 9  in a third configuration. 
         FIG. 51  is a back view of the medical injector illustrated in  FIG. 9  in a fourth configuration (i.e., the needle insertion configuration). 
         FIG. 52  is a front view of a portion of the medical injector illustrated in  FIG. 9  in the fourth configuration (i.e., the needle insertion configuration). 
         FIG. 53  is a front view of a portion of the medical injector illustrated in  FIG. 9  in a fifth configuration (i.e., the injection configuration). 
         FIG. 54  is a front view of the medical injector illustrated in  FIG. 9  in a sixth configuration (i.e., the retraction configuration). 
         FIG. 55  is an enlarged front cross-sectional view of a portion the medical injector illustrated in  FIG. 9  in the sixth configuration (i.e., the retraction configuration). 
         FIG. 56  is a cross-sectional front view of a medical injector according to an embodiment, in a first configuration. 
         FIG. 57  is a cross-sectional front view of the medical injector illustrated in  FIG. 56 , in a second configuration. 
         FIG. 58  is a perspective view of a portion of the medical injector illustrated in  FIG. 56 , in a first configuration. 
         FIG. 59  is a perspective view of a portion of the medical injector illustrated in  FIG. 56 , in a second configuration. 
         FIGS. 60 and 61  are perspective views of a medical injector according to an embodiment, in a first configuration. 
         FIG. 62  is a front view of the medical injector illustrated in  FIG. 60  with a cover removed. 
         FIG. 63  is a back view of the medical injector illustrated in  FIG. 60  with the cover removed. 
         FIG. 64  is a back view of a portion of the medical injector illustrated in  FIG. 60 . 
         FIG. 65  is a bottom perspective view of a housing of the medical injector illustrated in  FIG. 64 . 
         FIG. 66  is a front perspective views of a first portion of the housing of the medical injector illustrated in  FIGS. 62 and 63 . 
         FIG. 67  is a rear perspective views of the first portion of the housing of the medical injector illustrated in  FIG. 66 . 
         FIG. 68  is a front perspective views of a second portion of the housing of the medical injector illustrated in  FIGS. 62 and 63 . 
         FIG. 69  is a rear perspective views of the second portion of the housing of the medical injector illustrated in  FIG. 68 . 
         FIG. 70  is an enlarged view of a portion of the second portion of housing of the medical injector illustrated in  FIG. 69 . 
         FIG. 71  is a front view of a medicament delivery mechanism of the medical injector illustrated in  FIG. 60 . 
         FIG. 72  is an enlarged view of a portion of the medicament delivery mechanism on the medical injector illustrated in  FIG. 71 . 
         FIG. 73  is an enlarged view of a portion of the medicament delivery mechanism on the medical injector illustrated in  FIG. 71 . 
         FIG. 74  is an exploded view of a medicament container of the medical injector illustrated in  FIG. 60 . 
         FIG. 75  is a front view of a first movable member of the medical injector illustrated in  FIG. 60 , in a first configuration. 
         FIG. 76  is a front perspective view of the first movable member of the medical injector illustrated in  FIG. 75 , in a first configuration. 
         FIG. 77  is a rear perspective view of the first movable member of the medical injector illustrated in  FIG. 75 , in a first configuration. 
         FIG. 78  is a front view of a portion of the medical injector illustrated in  FIG. 60 . 
         FIG. 79  is a front perspective view of a second movable member of the medical injector illustrated in  FIG. 60 , in a first configuration. 
         FIG. 80  is a rear perspective view of the second movable member of the medical injector illustrated in  FIG. 79  in a first configuration. 
         FIGS. 81 and 82  are perspective views of a cover of the medical injector illustrated in  FIG. 60 . 
         FIG. 83  is a perspective view of a safety lock of the medical injector illustrated in  FIG. 60 . 
         FIG. 84  is a front view of the safety lock of the medical injector illustrated in  FIG. 83 . 
         FIG. 85  is a bottom view of the safety lock of the medical injector illustrated in  FIG. 83 . 
         FIG. 86  is a cross-section view of the safety lock of the medical injector illustrated in  FIG. 83 . 
         FIG. 87  is a perspective view of a needle sheath of the safety lock of the medical injector illustrated in  FIG. 83 . 
         FIG. 88  is a perspective view of a base of the medical injector illustrated in  FIG. 60 . 
         FIG. 89  is a front view of the base of the medical injector illustrated in  FIG. 88 . 
         FIG. 90  is a front view of the medical injector illustrated in  FIG. 60  in a third configuration. 
         FIG. 91  is a front view of a portion of the medical injector illustrated in  FIG. 60  in the third configuration. 
         FIG. 92  is a front view of the medical injector illustrated in  FIG. 60  in a fourth configuration (i.e., the needle insertion configuration). 
         FIG. 93  is a front view of a portion of the medical injector illustrated in  FIG. 60  in the fourth configuration (i.e., the needle insertion configuration). 
         FIG. 94  is an enlarged perspective view of a portion of the medical injector illustrated in  FIG. 60  in the fourth configuration (i.e., the needle insertion configuration). 
         FIG. 95  is a front view of the medical injector illustrated in  FIG. 60  in a fifth configuration (i.e., the injection configuration). 
         FIG. 96  is a perspective view of a first movable member of the medical injector illustrated in  FIG. 60  in a second configuration. 
         FIG. 97  is a front view of the medical injector illustrated in  FIG. 60  in a sixth configuration (i.e., the retraction configuration). 
         FIG. 98  is a front perspective view of a second movable member of the medical injector illustrated in  FIG. 60  in a second configuration. 
         FIG. 99  is a schematic illustration of a medicament delivery device according to an embodiment. 
         FIG. 100  is a schematic illustration of a medicament delivery device according to an embodiment. 
         FIG. 101  is a schematic illustration of a medicament delivery device according to an embodiment. 
         FIGS. 102 and 103  are perspective views of a medical injector according to an embodiment, in a first configuration. 
         FIG. 104  is a front view of the medical injector illustrated in  FIG. 102  with the cover removed. 
         FIG. 105  is a back view of the medical injector illustrated in  FIG. 102  with the cover removed. 
         FIG. 106  is a perspective view of a portion of the medical injector illustrated in  FIG. 102 . 
         FIG. 107  is a bottom perspective view of a housing of the medical injector illustrated in  FIG. 102 . 
         FIG. 108  is a top perspective view of a housing of the medical injector illustrated in  FIG. 102 . 
         FIG. 109  is a perspective view of a proximal cap of the medical injector illustrated in  FIG. 102 . 
         FIGS. 110 and 111  are front views of a medicament delivery mechanism of the medical injector illustrated in  FIG. 102 . 
         FIG. 112  is a perspective view of a portion of the medical injector illustrated in  FIG. 102 . 
         FIG. 113  is an exploded view of a medicament container of the medical injector illustrated in  FIG. 102 . 
         FIG. 114  is a front view of a portion of the medical injector illustrated in  FIG. 102 . 
         FIG. 115  is a back view of an electronic circuit system of the medical injector illustrated in  FIG. 102 . 
         FIG. 116  is a side view of the electronic circuit system of the medical injector illustrated in  FIG. 115 . 
         FIG. 117  is a front view of an electronic circuit system housing of the electronic circuit system illustrated in  FIG. 115 . 
         FIG. 118  is a perspective view of the electronic circuit system housing of the electronic circuit system illustrated in  FIG. 117 . 
         FIGS. 119 and 120  are perspective views of a cover of the medical injector illustrated in  FIG. 102 . 
         FIG. 121  is a perspective view of a safety lock of the medical injector illustrated in  FIG. 102 . 
         FIG. 122  is a bottom view of the safety lock of the medical injector illustrated in  FIG. 121 . 
         FIG. 123  is a perspective view of a needle sheath of the safety lock of the medical injector illustrated in  FIG. 121 . 
         FIG. 124  is a perspective view of a base of the medical injector illustrated in  FIG. 102 . 
         FIG. 125  is a front view of the base of the medical injector illustrated in  FIG. 102 . 
         FIG. 126  is a back view of the medical injector illustrated in  FIG. 102  in a second configuration. 
         FIG. 127  is a back view of the medical injector illustrated in  FIG. 102  in a third configuration. 
         FIG. 128  is a back view of the medical injector illustrated in  FIG. 102  in a fourth configuration (i.e., the needle insertion configuration). 
         FIG. 129  is a front view of the medical injector illustrated in  FIG. 102  in the fourth configuration (i.e., the needle insertion configuration). 
         FIG. 130  is a front view of the medical injector illustrated in  FIG. 102  in a fifth configuration (i.e., the injection configuration). 
         FIG. 131  is a front view of the medical injector illustrated in  FIG. 102  in a sixth configuration (i.e., the retraction configuration). 
         FIG. 132  is a perspective view of a housing of a medical injector according to an embodiment. 
         FIG. 133  is a perspective view of an electronic circuit system of a medical injector according to an embodiment. 
         FIG. 134  is a back view of a printed circuit board of the electronic circuit system shown in  FIG. 133 . 
         FIG. 135  is a schematic illustration of the electronic circuit system shown in  FIG. 133 . 
         FIG. 136  is a perspective cross-sectional view of the housing and the electronic circuit system illustrated in  FIG. 132  and  FIG. 133  respectively. 
         FIG. 137  is a cross-sectional perspective view of a portion of the electronic circuit system illustrated in  FIG. 133 , taken along line X-X in  FIG. 136 . 
         FIG. 138  is a schematic illustration of a medicament delivery device according to an embodiment. 
         FIG. 139  is a schematic illustration of a kit including a medicament container according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Medicament delivery devices for administration of opioid antagonists and chemical compositions used within such devices are described herein. In some embodiments, a naloxone composition can be formulated for use in a delivery device of the types shown and described herein. The naloxone composition includes an effective amount of naloxone i.e., 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one, or a pharmaceutically acceptable salt and/or ester thereof. As used herein, an “effective amount” is an amount sufficient to provide a desired therapeutic effect. In some embodiments, the naloxone composition can include a pH-adjusting agent, such as, for example, at least one of hydrochloric acid, citric acid, acetic acid, phosphoric acid, or combinations thereof. In some embodiments, the naloxone composition can include one or more tonicity-adjusting agents, such as, for example, at least one of dextrose, glycerin, mannitol, potassium chloride, sodium chloride, or combinations thereof. Because the naloxone composition may be stored in the medicament container of a delivery device for extended periods of time under varying storage conditions, in some embodiments the naloxone composition can include stabilizers to prevent or inhibit decomposition of the naloxone during storage. 
     In some embodiments, a medicament delivery device includes a housing, a medicament container disposed within the housing and an energy storage member disposed within the housing. The medicament container is filled with a naloxone composition that includes naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent, whereby the osmolality of the naloxone composition ranges from about 250-350 mOsm and the pH ranges from about 3-5. The energy storage member is configured to produce a force to deliver the naloxone composition. 
     In some embodiments, the medicament delivery device can further include an elastomeric member disposed within the medicament container that is configured to be compatible with the naloxone composition. Said another way, in some embodiments, an elastomeric member disposed within the medicament container can be formulated to prevent undesired leaching and/or reaction with the naloxone composition. In some embodiments, the elastomeric member is formulated to include a polymer and a curing agent. The polymer includes at least one of bromobutyl or chlorobutyl, and the curing agent includes at least one of sulfur, zinc or magnesium. 
     In some embodiments, the medicament delivery device can include an electronic circuit system coupled to the housing. The electronic circuit system is configured to produce an output when the electronic circuit system is actuated. The output can be, for example, an audible or visual output related to the naloxone composition (e.g., an indication of the expiration date, the symptoms requirement treatment with naloxone or the like), the use of the medicament delivery device, and/or post-administration procedures (e.g., a prompt to call 911, instructions for the disposal of the device or the like). 
     In some embodiments, a medicament delivery device includes a housing, a medicament container disposed within the housing, a delivery member coupled to the medicament container, and an energy storage member. The medicament container is filled with a naloxone composition. The energy storage member is disposed within the housing, and is configured to produce a force to deliver the naloxone composition from the medicament container via the delivery member such that the delivery member atomizes the naloxone composition. 
     In some embodiments, a kit includes a case and a medicament container movably disposed within the case. The medicament container filled with a naloxone composition. The medicament container includes a delivery member coupled thereto. The delivery member can be, for example, a needle, an atomizer or any other mechanism through which the naloxone composition can be conveyed from the medicament container into a body. 
     Medicament delivery devices for administration of medicaments contained within a prefilled syringe are described herein. In some embodiments, an apparatus includes a housing, a medicament container and a movable member. The medicament container, which can be, for example, a prefilled syringe, is configured to move within the housing between a first position and a second position in response to a force produced by an energy storage member. The energy storage member can be, for example, a spring, a compressed gas container, an electrical energy storage member or the like. A proximal end portion of the medicament container includes a flange and has a plunger disposed therein. The movable member is configured to move within the housing. A first shoulder of the movable member is configured to exert the force on the flange to move the medicament container from the first position to the second position. A portion of the first shoulder is configured to deform when the medicament container is in the second position such that at least a portion of the force is exerted upon the plunger. A second shoulder of the movable member is configured to exert a retraction force on the flange to move the medicament container from the second position towards the first position. 
     In some embodiments, a medicament delivery device includes a housing, a medicament container, a movable member and an energy storage member. The medicament container is configured to move within the housing between a first position and a second position in response to a force produced by the energy storage member. A proximal end portion of the medicament container includes a flange and has a plunger disposed therein. The movable member is configured to exert the force on the medicament container to move the medicament container from the first position to the second position. An engagement portion of the movable member is configured to limit movement of a piston surface relative to the plunger when the medicament container moves from the first position to the second position such that the piston surface is spaced apart from the plunger. The engagement portion is configured to deform when the medicament container is in the second position such that the piston surface is in contact with the plunger. 
     In some embodiments, a medicament delivery device includes a housing, a medicament container, a first movable member and a second movable member. The medicament container is configured to move within the housing between a first position and a second position in response to a force produced by an energy storage member. A proximal end portion of the medicament container includes a flange and has a plunger disposed therein. The first movable member is configured to move within the housing, and is operably coupled to the energy storage member such that a first portion of the first movable member is configured to exert at least a portion of the force on the flange to move the medicament container from the first position to the second position. A second portion of the first movable member is configured to deform when the medicament container is in the second position such that at least a portion of the force is exerted upon the plunger. The second movable member is configured to move with the medicament container when the medicament container moves from the first position to the second position. The second movable member is configured to move relative to the medicament container to move the plunger within the medicament container after the second portion of the first movable member is deformed. 
     In some embodiments, a medical device includes a carrier configured to be disposed within a housing of the medical device. The carrier is configured to contain at least a proximal portion of a medicament container, such as, for example a prefilled syringe having a flange. A first shoulder of the carrier is in contact with a proximal surface of the flange and a second shoulder of the carrier is in contact with a distal surface of the flange. The carrier has a first engagement portion configured to engage a movable member such that when a first force is exerted by the movable member on the first engagement portion, the first shoulder transfers at least a portion of the first force to the proximal surface of the flange. The carrier has a second engagement portion configured to engage a retraction spring such that when a second force is exerted by the retraction spring on the second engagement portion, the second shoulder transfers at least a portion of the second force to the distal surface of the flange. 
     In some embodiments, the medical device further includes a damping member disposed between the first shoulder of the carrier and the proximal surface of the flange of the medicament container, or between the second shoulder of the carrier and the proximal surface of the flange of the medicament container. The damping member can be disposed such that a portion of the first force or a portion of the second force is received and/or absorbed by the damping member to reduce the possibility of damage to the medicament container and/or flange. 
     In some embodiments, a medical device includes a housing, a movable member and a medicament container. The movable member is disposed within the housing and has a first engagement portion, a second engagement portion and a retraction portion. The first engagement portion is configured to be coupled to an energy storage member. The second engagement portion is configured to be coupled to the medicament container such that a shoulder of the second engagement portion exerts a first force produced by the energy storage member on the medicament container to move the medicament container within the housing in a first direction. The retraction portion is configured to produce a second force to move the medicament container within the housing in a second direction. In some embodiments, the retraction portion includes a spring that is monolithically constructed with at least the second engagement portion. 
     As used in this specification and the appended claims, the words “proximal” and “distal” refer to direction closer to and away from, respectively, an operator of the medical device. Thus, for example, the end of the medicament delivery device contacting the patient&#39;s body would be the distal end of the medicament delivery device, while the end opposite the distal end would be the proximal end of the medicament delivery device. 
     Throughout the present specification, the terms “about” and/or “approximately” may be used in conjunction with numerical values and/or ranges. The term “about” is understood to mean those values near to a recited value. For example, “about 40 [units]” may mean within ±25% of 40 (e.g., from 30 to 50), within ±20%, ±15%, ±10%, ±9%, ±8%, ±7%, ±7%, ±5%, ±4%, ±3%, ±2%, ±1%, less than ±1%, or any other value or range of values therein or therebelow. Furthermore, the phrases “less than about [a value]” or “greater than about [a value]” should be understood in view of the definition of the term “about” provided herein. The terms “about” and “approximately” may be used interchangeably. 
     Throughout the present specification, numerical ranges are provided for certain quantities. It is to be understood that these ranges comprise all subranges therein. Thus, the range “from 50 to 80” includes all possible ranges therein (e.g., 51-79, 52-78, 53-77, 54-76, 55-75, 70-70, etc.). Furthermore, all values within a given range may be an endpoint for the range encompassed thereby (e.g., the range 50-80 includes the ranges with endpoints such as 55-80, 50-75, etc.). 
     Throughout the present specification, the words “a” or “an” are understood to mean “one or more” unless explicitly stated otherwise. Further, the words “a” or “an” and the phrase “one or more” may be used interchangeably. 
       FIGS. 1-4  are schematic illustrations of a medicament delivery device  1000  according to an embodiment in a first, second, third and fourth configuration, respectively. The medicament delivery device  1000  includes a housing  1100 , a medicament container  1200 , a movable member  1300 , an energy storage member  1400  and a retraction member  1351 . The housing  1100  can be any suitable size, shape, or configuration and can be made of any suitable material. For example, in some embodiments, the housing  1100  is an assembly of multiple parts formed from a plastic material and defines a substantially rectangular shape when assembled. 
     The medicament container  1200  is disposed within the housing  1100 , and contains (i.e., is filled or partially filled with) a medicament. The medicament container  1200  includes a proximal end portion  1212  that has a flange  1214  and a distal end portion  1213  that is coupled to a needle (not shown in  FIGS. 1-4 ). The medicament container  1200  includes an elastomeric member  1217  (also referred to herein as a “plunger”). The elastomeric member  1217  is formulated to be compatible with the medicament housed within the medicament container  1200 . Similarly stated, the elastomeric member  1217  is formulated to minimize any reduction in the efficacy of the medicament that may result from contact (either direct or indirect) between the elastomeric member  1217  and the medicament. For example, in some embodiments, the elastomeric member  1217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the medicament. The elastomeric member  1217  is disposed within the medicament container  1200  to seal the proximal end portion  1212  of the medicament container  1200 . In some embodiments, the elastomeric member  1217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with a medicament over a long period of time (e.g., for up to six months, one year, two years, five years or longer). The medicament container  1200  can be any container suitable for storing the medicament. In some embodiments, the medicament container  1200  can be, for example, a prefilled syringe having a staked needle at the distal end thereof. In those embodiments in which the medicament container  1200  is a prefilled syringe, the elastomeric member  1217  can be disposed within the medicament container  1200  during the fill process (e.g., before being placed in the housing  1100 ). 
     The energy storage member  1400  can be any suitable device or mechanism that, when actuated, produces a force F1 to deliver the medicament contained within the medicament container  1200 . Similarly stated, the energy storage member  1400  can be any suitable device or mechanism that produces the force F1 such that the medicament is conveyed from the medicament container  1200  into a body of a patient. More specifically, the energy storage member  1400  produces the force F1 that moves the medicament container  1200  from a first position to a second position in a first direction indicated by the arrow AA in  FIG. 2  and/or that moves the plunger  1217  from a first plunger position to a second plunger position as shown by the arrow BB in  FIG. 3 . The medicament can be conveyed into a body via any suitable mechanism, such as, for example, by injection. By employing the energy storage member  1400  to produce the force F1 rather than relying on a user to manually produce the delivery force, the medicament can be delivered into the body at the desired pressure and/or flow rate, and with the desired delivery characteristics. Moreover, this arrangement reduces the likelihood of partial delivery (e.g., that may result if the user is interrupted or otherwise rendered unable to manually produce the force to complete the delivery). 
     In some embodiments, the energy storage member  1400  can be a mechanical energy storage member, such as a spring, a device containing compressed gas, a device containing a vapor pressure-based propellant or the like. In other embodiments, the energy storage member  1400  can be an electrical energy storage member, such as a battery, a capacitor, a magnetic energy storage member or the like. In yet other embodiments, the energy storage member  1400  can be a chemical energy storage member, such as a container containing two substances that, when mixed, react to produce energy. 
     The energy storage member  1400  can be disposed within the housing in any position and/or orientation relative to the medicament container  1200 . In some embodiments, for example, the energy storage member  1400  can be positioned within the housing  1100  spaced apart from the medicament container  1200 . Moreover, in some embodiments, the energy storage member  1400  can be positioned such that a longitudinal axis of the energy storage member  1400  is offset from the medicament container  1200 . In other embodiments, the energy storage member  1400  can substantially surround the medicament container  1200 . 
     As shown in  FIG. 1 , the energy storage member  1400  is operably coupled to the movable member  1300 , the medicament container  1200  and/or the medicament therein such that the force F1 delivers the medicament. In some embodiments, for example, the force F1 can be transmitted to the medicament container  1200  and/or the medicament therein via the movable member  1300 . The movable member  1300  can be any suitable member, device, assembly or mechanism configured to move within the housing  1100 . As shown in  FIGS. 1-4 , the movable member  1300  includes a piston portion  1330  configured to transmit the force F1 to the plunger  1217  disposed within the medicament container  1200 . 
     The movable member  1300  includes a first shoulder  1335  and a second shoulder  1337 . The first shoulder  1335  of the movable member  1300  is configured to exert the force F1, produced by the energy storage member  1400 , on the flange  1214  of the medicament container  1200 . In this manner, when the medicament delivery device  1000  is actuated to produce the force F1, movable member  1300  moves the medicament container  1200  from the first position (see  FIG. 1 , which corresponds to the first configuration of the medicament delivery device  1000 ) to the second position (see  FIG. 2 , which corresponds to the second configuration of the medicament delivery device  1000 ). In some embodiments, the movement of the medicament container  1200  within the housing  1100  results in a needle insertion operation. Although the first shoulder  1335  is shown as directly contacting the flange  1214  when the medicament delivery device  1000  is in the second configuration ( FIG. 2 ), in other embodiments, there can be intervening structure (e.g., an o-ring, a damping member, or the like) disposed between the first shoulder  1335  and the flange  1214 . 
     In some embodiments, the first shoulder  1335  of the movable member  1300  can be configured to maintain a distance between the piston portion  1330  of the movable member  1300  and the plunger  1217  when the medicament delivery device  1000  is in the first configuration ( FIG. 1 ). Similarly stated, in some embodiments, the movable member  1300  and the medicament container  1200  are collectively configured such that the piston portion  1330  is spaced apart from the plunger  1217  when the medicament delivery device  1000  is in its storage configuration and/or when the medicament container  1200  is moving between its first position and its second position. In this manner, any preload or residual force produced by the energy storage member  1400  on the movable member  1300  is not transferred to the plunger  1217 . Said another way, the plunger  1217  is isolated from the energy storage member  1400  during the storage configuration. Accordingly, this arrangement reduces and/or eliminates medicament leakage from the medicament container  1200 . 
     As shown in  FIG. 3 , the first shoulder  1335  includes a deformable portion  1338  configured to deform when the medicament container  1200  is in the second position such that at least a portion of the force F1 is exerted upon the plunger  1217 . In some embodiments, the deformable portion  1338  can be separated from the piston portion  1330  of the movable member  1300 . In other embodiments, the deformable portion  1338  is configured to bend, deform, rotate and/or otherwise move relative to the piston portion  1300  such that the piston portion  1330  is placed into contact (directly or indirectly via intervening structure) with the plunger  1217 . Similarly stated, in some embodiments, the deformable portion  1338  is configured to bend, deform, rotate and/or otherwise move relative to the piston portion  1300  such that the first shoulder  1335  no longer maintains the distance between the piston portion  1300  and the plunger  1217 . In this manner, the piston portion  1330  transmits at least a portion of the force F1 to the plunger  1217 , thereby placing the medicament container  1200  into the third configuration ( FIG. 3 ). More specifically, when the deformable portion  1338  deforms, the piston portion  1330  moves within the medicament container  1200  in the direction of the arrow BB ( FIG. 3 ) and moves the plunger  1217  from the proximal end portion  1212  of the medicament container  1200  towards the distal end portion  1213  of the medicament container  1200 . This arrangement allows for the delivery of the medicament contained within the medicament container  1200  into a body of a patient. 
     When the medicament is delivered, the retraction member  1351  exerts a retraction force F2 on at least the second shoulder  1337  of the movable member  1300  in a second direction, opposite the first direction. When the retraction force F2 is exerted, the second shoulder  1337  engages a distal surface of the flange  1214  of the medicament container  1200 , thereby exerting at least a portion of the retraction force F2 on the flange  1214 . Although the second shoulder  1337  is shown as directly contacting the flange  1214  when the medicament delivery device  1000  is in the fourth configuration ( FIG. 4 ), in other embodiments, there can be intervening structure (e.g., an o-ring, a damping member, or the like) disposed between the second shoulder  1337  and the flange  1214 . The exertion of the retraction force F2 on the flange  1214  moves the medicament container  1200  from the second position (e.g., the second and third configuration, as shown in  FIGS. 2 and 3 ) in the direction of the arrow CC toward the first position. In this manner, the retraction member  1351  produces the retraction force F2 and moves the distal end portion  1213  of the medicament container  1200  (which can include, for example, a needle) away from the body of the patient and into the housing  1100  of the medicament delivery device  1000 . 
     The retraction member  1351  can be any suitable device or mechanism that, when actuated, produces a force F2 to move the medicament container  1200  in the second direction as indicated by the arrow CC in  FIG. 4 . In some embodiments, the retraction member  1351  can be a mechanical energy storage member, such as a spring, a device containing compressed gas, a device containing a vapor pressure-based propellant or the like. In other embodiments, the retraction member  1351  can be an electrical energy storage member, such as a battery, a capacitor, a magnetic energy storage member or the like. In yet other embodiments, the retraction member  1351  can be a chemical energy storage member, such as a container containing two substances that, when mixed, react to produce energy. Although the retraction member  1351  is shown as being separate and distinct from the energy storage member  1400 , in some embodiments, the energy storage member  1400  can be configured to produce the retraction force F2. 
     The retraction member  1351  can be in any position and/or orientation relative to the medicament container  1200 . In some embodiments, for example, the retraction member  1351  can be positioned within the housing  1100  spaced apart from the medicament container  1200 . Moreover, in some embodiments, the retraction member  1351  can be positioned such that a longitudinal axis of the retraction member  1351  is offset from the medicament container  1200 . In other embodiments, the retraction member  1351  can substantially surround the medicament container  1200 . In some embodiments, the retraction member  1351  is coupled to the second shoulder  1337  of the movable member  1300 . In other embodiments, the retraction member  1351  is monolithically formed with the movable member  1300 . 
       FIGS. 5-8  are schematic illustrations of a medicament delivery device  2000  according to an embodiment in a first, second, third and fourth configuration, respectively. The medicament delivery device  2000  includes a housing  2100 , a medicament container  2200 , a first movable member  2300 , a second movable member  2345  and an energy storage member  2400 . The housing  2100  can be any suitable size, shape, or configuration and can be made of any suitable material. For example, in some embodiments, the housing  2100  is an assembly of multiple parts formed from a plastic material and defines a substantially rectangular shape when assembled. 
     The medicament container  2200  is disposed within the housing  2100 , and contains (i.e., is filled or partially filled with) a medicament. The medicament container  2200  includes a proximal end portion  2212  that has a flange  2214  and a distal end portion  2213  that is coupled to a delivery member, such as a needle, nozzle or the like (not shown in  FIGS. 5-8 ). The medicament container  2200  includes an elastomeric member  2217 . The elastomeric member  2217  is formulated to be compatible with the medicament housed within the medicament container  2200 . Similarly stated, the elastomeric member  2217  is formulated to minimize any reduction in the efficacy of the medicament that may result from contact (either direct or indirect) between the elastomeric member  2217  and the medicament. For example, in some embodiments, the elastomeric member  2217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the medicament. The elastomeric member  2217  is disposed within the medicament container  2200  to seal the proximal end portion  2212  of the medicament container  2200 . In some embodiments, the elastomeric member  2217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with a medicament over a long period of time (e.g., for up to six months, one year, two years, five years or longer). The medicament container  2200  can be any container suitable for storing the medicament. In some embodiments, the medicament container  2200  can be, for example, a prefilled syringe having a staked needle at the distal end thereof. In those embodiments in which the medicament container  1200  is a prefilled syringe, the elastomeric member  2217  is disposed within the medicament container  2200  during the fill process (e.g., before the prefilled syringe is placed in the housing  2100 ). 
     The energy storage member  2400  can be any suitable device or mechanism that, when actuated, produces a force F3 to deliver the medicament contained within the medicament container  2200 . Similarly stated, the energy storage member  2400  can be any suitable device or mechanism that produces the force F3 such that the medicament is conveyed from the medicament container  2200  into a body of a patient. More specifically, the energy storage member  2400  produces the force F3 that moves the medicament container  2200  from a first position to a second position in a first direction indicated by the arrow DD in  FIG. 6  and/or that moves the plunger  2217  from a first plunger position to a second plunger position, as shown by the arrow EE in  FIG. 7 . The medicament can be conveyed into a body via any suitable mechanism, such as, for example, by injection via a needle, nozzle or the like. 
     In some embodiments, the energy storage member  2400  can be a mechanical energy storage member, such as a spring, a device containing compressed gas, a device containing a vapor pressure-based propellant or the like. In other embodiments, the energy storage member  2400  can be an electrical energy storage member, such as a battery, a capacitor, a magnetic energy storage member or the like. In yet other embodiments, the energy storage member  2400  can be a chemical energy storage member, such as a container containing two substances that, when mixed, react to produce energy. 
     The energy storage member  2400  can be in any position and/or orientation relative to the medicament container  2200 . In some embodiments, for example, the energy storage member  2400  can be positioned within the housing  2100  spaced apart from the medicament container  2200 . Moreover, in some embodiments, the energy storage member  2400  can be positioned such that a longitudinal axis of the energy storage member  2400  is offset from the medicament container  2200 . In other embodiments, the energy storage member  2400  can substantially surround the medicament container  2200 . 
     As shown in  FIG. 5 , the energy storage member  2400  is operably coupled to the first movable member  2300 , the second movable member  2345 , the medicament container  2200  and/or the medicament therein such that the force F3 delivers the medicament. In some embodiments, for example, the force F3 can be transmitted to the medicament and/or the medicament container  2200  via the first movable member  2300  and/or the second movable member  2345 . As described in more detail herein, the first movable member  2300  and the second movable member  2345  are collectively configured to transmit the force F3 to the plunger  2217  disposed within the medicament container  2200 . 
     The first movable member  2300  includes a first portion  2335  and a second portion  2338 . The first portion  2335  of the movable member  2300  is configured to transmit and/or exert at least a portion of the force F3 produced by the energy storage member  2400  on the flange  2214  of the medicament container  2200  to move the medicament container  2200  from the first position (see  FIG. 5 , which corresponds to the first configuration of the medicament delivery device  2000 ) to the second position (see  FIG. 6 , which corresponds to the second configuration of the medicament delivery device  2000 ). Although the medicament container  2200  is shown as being within the housing  2100  when the medicament container  2200  is in the second position, in some embodiments, the movement of the medicament container  2200  can result in a needle insertion operation in which a needle (not shown in  FIGS. 5-8 ) is extended outside of the housing  2100 . The first portion  2335  of the movable member  2300  can be, for example, a first shoulder, protrusion, sleeve or the like. Although the first portion  2335  is shown as directly contacting the flange  2214  when the medicament delivery device  2000  is in the second configuration ( FIG. 6 ), in other embodiments, there can be intervening structure (e.g., an o-ring, a damping member, or the like) disposed between the first portion  2335  and the flange  2214 . 
     The second portion  2338  of the first movable member  2300  maintains the second movable member  2345  in a first position ( FIGS. 5 and 6 ), relative to the medicament container  2200  and/or the first movable member  2300  when the medicament delivery device  2000  is in the first (i.e., storage) configuration ( FIG. 5 ). In this manner, as shown in  FIG. 6 , at least a portion of the force F3 can be transferred from the energy storage member  2400  to the first movable member  2300  (and to the flange  2214 ) via the second movable member  2345 . Thus, when the medicament container  2200  is moved from its first position to its second position, the second movable member  2345  moves with the medicament container  2200  and/or the first movable member  2300 . 
     In some embodiments, the second portion  2338  can engage the second movable member  2345  to maintain a distance (e.g., an air gap, space, or void) between the second movable member  2345  and the plunger  2217 , when the medicament container  2200  is in the first configuration ( FIG. 1 ) and/or when the medicament container  2200  is moving between its first position and its second position. In this manner, any preload or residual force produced by the energy storage member  1400  on the second movable member  2345  is not transferred to the plunger  2217 . Said another way, the plunger  2217  is substantially isolated from the energy storage member  2400  during the storage configuration and/or when the medicament container  2200  is moving. Accordingly, this arrangement reduces and/or eliminates medicament leakage from the medicament container  2200 . 
     When the medicament container  2200  in the second position ( FIGS. 6 and 7 ), the second portion  2338  of the first movable member  2300  is configured to deform (e.g., by a portion of the force F3), thereby allowing movement of the second movable member  2345  relative to the first movable member  2300  and/or the medicament container  2200 . Thus, when the second portion  2338  of the first movable member  2300  deforms, at least a portion of the force F3 is exerted upon the plunger  2217 . Similarly stated, when the medicament delivery device  2000  is in the second configuration ( FIG. 6 ), a portion of the force F3 can deform the second portion  2338  of the movable member  2300  ( FIG. 7 ). After the second portion  2338  is deformed, at least a portion of the force F3 is transmitted from the second movable member  2345  to the plunger  2217  to place the medicament container  2200  in the third configuration ( FIG. 7 ). More specifically, when the second portion  2338  deforms, the second movable member  2345  moves in the direction of the arrow EE ( FIG. 7 ) and moves the plunger  2217  from the proximal end portion  2212  of the medicament container  2200  toward the distal end portion  2213  of the medicament container  2200 . Similarly stated, when the second portion  2338  deforms, the second movable member  2345  moves relative to the medicament container  2200  to move the plunger  2217  within the medicament container  2200 . This arrangement allows for the delivery of the medicament contained within the medicament container  2200  into a body of a patient, as shown in  FIG. 8 . 
     In some embodiments, the medicament delivery device  2000  can include a retraction member (not shown in  FIGS. 5-8 ). The retraction member can be any suitable device and/or mechanism configured to move the medicament container  2200  from the second position (e.g., the fourth configuration shown in  FIG. 8 ) toward the first position (e.g. the first configuration shown in  FIG. 5 ). In some embodiments, the retraction member can be substantially similar to the retraction member  1351  described with respect to  FIGS. 1-4 . In such embodiments, the retraction member can be configured to transmit a force to the flange  2214  of the medicament container  2200  and move the medicament container  2200  in a second direction opposite the first direction indicated by the arrow DD in  FIG. 6 . 
     In some embodiments, the medicament delivery device can be a medical injector configured to automatically deliver a medicament contained within a medicament container, such as, for example a prefilled syringe. For example,  FIGS. 9-55  show a medical injector  3000 , according to an embodiment.  FIGS. 9-10  are perspective views of the medical injector  3000  in a first configuration (i.e., prior to use). The medical injector  3000  includes a housing  3100  (see e.g.,  FIGS. 11-17 ), a system actuation assembly  3500  (see e.g.,  FIGS. 18-21 ), a medicament container  3200  containing a medicament  3220  (see e.g.,  FIG. 22 ), a medicament delivery mechanism  3300  (see e.g.,  FIG. 26-28 ), an electronic circuit system  3900  (see e.g.,  FIGS. 29-39 ), a cover  3190  (see e.g.,  FIGS. 40-41 ), and a safety lock  3700  (see e.g.,  FIGS. 42-46 ). A discussion of the components of the medical injector  3000  will be followed by a discussion of the operation of the medical injector  3000 . 
     As shown in  FIGS. 11-17 , the housing  3100  has a proximal end portion  3101  and a distal end portion  3102 . The housing  3100  defines a first status indicator aperture  3130  and a second status indicator aperture  3160 . The first status indicator aperture  3130  defined by the housing  3100  is located on a first side of the housing  3100 , and the second status indicator aperture  3160  of the housing  3100  is located on a second side of the housing  3100 . The status indicator apertures  3130 ,  3160  can allow a patient to monitor the status and/or contents of the medicament container  3200  contained within the housing  3100 . For example, by visually inspecting the status indicator apertures  3130 ,  3160 , a patient can determine whether the medicament container  3200  contains a medicament  3220  and/or whether the medicament  3220  has been dispensed. 
     As shown in  FIGS. 15 and 16 , the housing  3100  defines a gas cavity  3151 , a medicament cavity  3139  and an electronic circuit system cavity  3137 . The gas cavity  3151  has a proximal end portion  3152  and a distal end portion  3153 . The gas cavity  3151  is configured to receive the gas container  3410  and a portion of the system actuator assembly  3500  (e.g., a release member  3550  and the spring  3576 , as shown in  FIGS. 18 and 19 ) as described in further detail herein. The proximal end portion  3152  of the gas cavity  3151  is configured to receive the gas container retention member  3580  of a proximal cap  3103  of the housing  3100 , as described in further detail herein. The gas cavity  3151  is in fluid communication with the medicament cavity  3139  via a gas passageway  3156  (see e.g.,  FIG. 17 ), as described in further detail herein, and the gas cavity  3151  is in fluid communication with a region outside the housing  3100  via a release member aperture  3154  (see e.g.,  FIGS. 15 and 16 ). 
     The medicament cavity  3139  is configured to receive the medicament container  3200  and at least a portion of the medicament delivery mechanism  3300 . In particular, as described below, the medicament delivery mechanism  3300  includes a carrier  3370  and piston member  3330  movably disposed in the medicament cavity  3139 . The medicament cavity  3139  is in fluid communication with a region outside the housing  3100  via a needle aperture  3105  (see e.g.,  FIGS. 15 and 16 ). 
     The electronic circuit system cavity  3137  is configured to receive the electronic circuit system  3900 . The housing  3100  has protrusions  3136  (see e.g.,  FIG. 14 ) configured to stabilize the electronic circuit system  3900  when the electronic circuit system  3900  is disposed within the electronic circuit system cavity  3137 . The outer surface of the housing  3100  is configured to receive a set of connection protrusions  3174 A and connection protrusion  3174 B of the electronic circuit system  3900  (see e.g.,  FIG. 32 ). In this manner, the electronic circuit system  3900  can be coupled to the housing  3100  within the electronic circuit system cavity  3137 . In other embodiments, the electronic circuit system  3900  can be coupled within the electronic circuit system cavity  3137  by other suitable means such as an adhesive, a clip, a label and/or the like. 
     The electronic circuit system cavity  3137  is fluidically and/or physically isolated from the gas cavity  3151  and/or the medicament cavity  3139  by a sidewall  3150 . The sidewall  3150  can be any suitable structure to isolate the electronic circuit system cavity  3137  within the housing  3100  from the gas cavity  3151  and/or the medicament cavity  3139  within the housing  3100 . Similarly, the gas cavity  3151  and the medicament cavity  3139  are separated by a sidewall  3155  (see  FIG. 16 ). In some embodiments, sidewall  3155  can be similar to the sidewall  3150 , which isolates the gas cavity  3151  and the medicament cavity  3139  from the electronic circuit system cavity  3137 . In other embodiments, the gas cavity  3151  can be fluidically and/or physically isolated from the medicament cavity  3139  by any suitable means. In yet other embodiments, the medicament cavity  3139  need not be fluidically and/or physically isolated from the electronic circuit system cavity  3137  and/or the gas cavity  3151 . 
     The proximal end portion  3101  of the housing  3100  includes a proximal cap  3103  (see e.g.,  FIG. 17 ), a speaker protrusion  3138  (see e.g.,  FIGS. 14-16 ), and cover retention protrusions  3104  (see e.g.,  FIGS. 10 and 12 ). The speaker protrusion  3138  is configured to maintain a position of an audio output device  3956  of the electronic circuit system  3900  relative to the housing  3100  when the electronic circuit system  3900  is attached to the housing  3100 , as described herein. The cover retention protrusions  3104  are configured to be received within corresponding openings  3193  defined by the cover  3190  (see e.g.,  FIG. 10 ) to retain the cover  3190  about the housing  3100 . In this manner, as described in more detail herein, the cover  3190  is removably coupled to and disposed about at least a portion of the housing  3100 . 
     As shown in  FIG. 17 , the proximal cap  3103  includes a gas container retention member  3580  and defines a gas passageway  3156 . The gas container retention member  3580  is configured to receive and/or retain a gas container  3410  that contains a pressurized gas, as shown in  FIG. 18 . When the medical injector  3000  is actuated, pressurized gas from the gas container  3140  is conveyed from the gas cavity  3151  to the medicament cavity  3139  via the gas passageway  3156 , as further described herein. Said another way, the gas passageway  3156  places the gas cavity  3151  in fluid communication with the medicament cavity  3139 . 
     As shown in  FIGS. 13 and 15 , the distal end portion  3102  of the housing  3100  defines a battery isolation protrusion aperture  3135 , a needle aperture  3105 , a safety lock actuator groove  3133 , a release member contact surface  3126 , a release member aperture  3154 , a base protrusion groove  3132 , base retention recesses  3134 A,  3134 B, and base rail grooves  3114 . The battery isolation protrusion aperture  3135  receives the battery isolation protrusion  3197  of the cover  3190  (see e.g.,  FIG. 41 ) when the cover  3190  is disposed about at least a portion of the housing  3100 . The needle aperture  3105  is the opening through which the needle  3216  is disposed (see e.g.,  FIGS. 19, 51 and 52 ) when the medical injector  3000  is actuated, as described in further detail herein. 
     The safety lock actuator groove  3133  receives an actuator  3724  of the safety lock  3700  (see e.g.,  FIG. 43 ). As described in more detail herein, the actuator  3724  is configured to engage and/or activate the electronic circuit system  3900  when the safety lock  3700  is moved with respect to the housing  3100 . The release member contact surface  3126  defines the release member aperture  3154 . As shown in  FIG. 21  and described in more detail below, the release member aperture  3154  receives a distal end portion  3552  of a release member  3550 . As described in more detail below, a safety lock protrusion  3702  (see e.g.,  FIG. 42 ) is disposed within an opening  3556  between extensions  3553  of the release member  3550  (see e.g.,  FIGS. 19 and 21 ) such that an engagement surface  3554  of the extensions  3553  is engaged with the release member contact surface  3126  to prevent activation of the medical injector  3000 . The safety lock  3700 , its components and functions are described in more detail below. 
     The distal base retention recesses  3134 A are configured to receive the base connection knobs  3518  of the actuator  3510  (also referred to herein as “base  3510 ,” see e.g.,  FIG. 47 ) when the base  3510  is in a first position relative to the housing  3100 . The proximal base retention recesses  3134 B are configured to receive the base connection knobs  3518  of the base  3510  when the base  3510  is in a second position relative to the housing  3100 . The base retention recesses  3134 A,  3134 B have a tapered proximal sidewall and a non-tapered distal sidewall. This allows the base retention recesses  3134 A,  3134 B to receive the base connection knobs  3518  such that the base  3510  can move proximally relative to the housing  3100 , but cannot move distally relative to the housing  3100 . Said another way, the distal base retention recesses  3134 A are configured to prevent the base  3510  from moving distally when the base  3510  is in a first position and the proximal base retention recesses  3134 B are configured to prevent the base  3510  from moving distally when the base  3510  is in a second position. Similarly stated, the proximal base retention recesses  3134 B and the base connection knobs  3518  cooperatively to limit movement of the base to prevent undesirable movement of the base  3510  after the medical injector  3000  is actuated. The proximal base retention recesses  3134 B and the base connection knobs  3518  also provide a visual cue to the user that the medical injector  3000  has been used. 
     The base actuator groove  3132  receives a protrusion  3520  of the base  3510 . As described in more detail herein, the protrusion  3520  of the base  3510  is configured to engage the electronic circuit system  3900  when the base  3510  is moved with respect to the housing  3100 . The base rail grooves  3114  receive the guide members  3517  of the base  3510  (see FIG.  47 ). The guide members  3517  of the base  3510  and the base rail grooves  3114  of the housing  3100  engage each other in a way that allows the guide members  3517  of the base  3510  to slide in a proximal and/or distal direction within the base rail grooves  3114  while limiting lateral movement of the guide members  3517 . This arrangement allows the base  3510  to move in a proximal and/or distal direction with respect to the housing  3100  but prevents the base  3510  from moving in a lateral direction with respect to the housing  3100 . 
       FIGS. 18-28  show the medicament container  3200 , the system actuator assembly  3500  and the medicament delivery mechanism  3300  of the medical injector  3000 . The medicament container  3200  has a body  3210  with a distal end portion  3213  and a proximal end portion  3212 . The body  3210  defines a volume that contains (i.e., is filled with or partially filled with) a medicament  3220  (see, e.g.,  FIGS. 22 and 28 ). The distal end portion  3213  of the medicament container  3200  includes a neck  3215  that is coupled to the needle  3216 , as described below. The proximal end portion  3212  of the medicament container  3200  includes an elastomeric member  3217  (i.e., a plunger) that seals the medicament  3220  within the body  3210 . The elastomeric member  3217  is configured to move within the body to inject the medicament  3220  from the medicament container  3200 . More particularly, as shown in  FIG. 27 , the elastomeric member  3217  is configured to receive and/or contact a piston rod  3333  of a piston member  3330  (also referred to herein as “second movable member  3330 ”) of the medicament delivery mechanism  3300 . 
     The elastomeric member  3217  can be of any design or formulation suitable for contact with the medicament  3220 . For example, the elastomeric member  3217  can be formulated to minimize any reduction in the efficacy of the medicament  3220  that may result from contact (either direct or indirect) between the elastomeric member  3217  and the medicament  3220 . For example, in some embodiments, the elastomeric member  3217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the medicament  3220 . In other embodiments, the elastomeric member  3217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with the medicament  3220  over a long period of time (e.g., for up to six months, one year, two years, five years or longer). 
     In some embodiments, the elastomeric member  3217  can be constructed from multiple different materials. For example, in some embodiments, at least a portion of the elastomeric member  3217  can be coated. Such coatings can include, for example, polydimethylsiloxane. In some embodiments, at least a portion of the elastomeric member  3217  can be coated with polydimethylsiloxane in an amount of between approximately 0.02 mg/cm 2  and approximately 0.80 mg/cm 2 . 
     The proximal end portion  3212  of the body  3210  includes a flange  3214  configured to be disposed within a portion of the carrier  3370  (also referred to as a first movable member  3370 ), as described in further detail herein. The flange  3214  can be of any suitable size and/or shape. Although shown as substantially circumscribing the body  3210 , in other embodiments, the flange  3214  can only partially circumscribe the body  3210 . 
     The medicament container  3200  can have any suitable size (e.g., length and/or diameter) and can contain any suitable volume of the medicament  3220 . Moreover, the medicament container  3200  and the second movable member  3330  can be collectively configured such that the second movable member  3330  travels a desired distance within the medicament container  3200  (i.e., the “stroke”) during an injection event. In this manner, the medicament container  3200 , the volume of the medicament  3220  within the medicament container  3200  and the second movable member  3330  can be collectively configured to provide a desired fill volume and delivery volume. For example, the medicament container  3200 , as shown in  FIG. 22 , is a prefilled syringe having a predetermined fill volume. Based on the predetermined fill volume, the second movable member  3330  can be configured to provide a desired delivery volume. 
     Moreover, the length of the medicament container  3200  and the length of the second movable member  3330  can be configured such that the medicament delivery mechanism  3300  can fit within the same housing  3100  regardless of the fill volume, the delivery volume and/or the ratio of the fill volume to the delivery volume. In this manner, the same housing and production tooling can be used to produce devices having various dosages of the medicament  3220 . For example, in a first embodiment (e.g., having a fill volume to delivery volume ratio of 0.4), the medicament container has a first length and the second movable member has a first length. In a second embodiment (e.g., having a fill volume to delivery volume ratio of 0.6), the medicament container has a second length shorter than the first length, and the second movable member has a second length longer than the first length. In this manner, the stroke of the device of the second embodiment is longer than that of the device of the first embodiment, thereby allowing a greater dosage. The medicament container of the device of the second embodiment, however, is shorter than the medicament container of the device of the first embodiment, thereby allowing the components of both embodiments to be disposed within the same housing and/or a housing having the same length. 
     As shown in  FIGS. 18-21 , the system actuator assembly  3500  includes the base  3510 , a release member  3550  and a spring  3576 .  FIG. 19  shows certain internal components of the medical injector  3000  without the base  3510  and the spring  3576  so that the release member  3550  can be more clearly shown. 
     The release member  3550  has a proximal end portion  3551  and a distal end portion  3552 , and is movably disposed within the distal end portion  3153  of the gas cavity  3151 . The proximal end portion  3551  of the release member  3550  includes a sealing member  3574  and a puncturer  3575 . The sealing member  3574  is configured to engage the sidewall of the housing  3100  defining the gas cavity  3151  such that the proximal end portion  3152  of the gas cavity  3151  is fluidically isolated from the distal end portion  3153  of the gas cavity  3151 . In this manner, when gas is released from the gas container  3410 , the gas contained in the proximal end portion  3152  of the gas cavity  3151  is unable to enter the distal end portion  3153  of the gas cavity  3151 . The puncturer  3575  of the proximal end portion  3551  of the release member  3550  is configured to contact and puncture a frangible seal  3413  on the gas container  3410  when the release member  3550  moves proximally within the gas cavity  3151 , as shown by the arrow FF in  FIG. 19 . 
     The distal end portion  3552  of the release member  3550  includes extensions  3553 . The extensions  3553  have projections  3555  that include tapered surfaces  3557  and engagement surfaces  3554 . Further, the extensions  3553  define an opening  3556  between the extensions  3553 . The engagement surfaces  3554  of the projections  3555  are configured to extend through the release member aperture  3154  of the housing  3100  and contact the release member contact surface  3126  of the housing  3100 , as shown in  FIG. 21 . In this manner, the engagement surfaces  3554  of the projections  3555  limit proximal movement of the release member  3550  when the engagement surfaces  3554  are in contact with the release member contact surface  3126  of the housing  3100 . 
     The opening  3556  defined by the extensions  3553  is configured to receive the safety lock protrusion  3702  of the safety lock  3700  (see e.g.,  FIGS. 21 and 42 ) when the safety lock  3700  is coupled to the housing  3100  and/or the base  3510 . The safety lock protrusion  3702  is configured to prevent the extensions  3553  from moving closer to each other. Said another way, the safety lock protrusion  3702  is configured to ensure that the extensions  3553  remain spaced apart and the engagement surfaces  3554  of the projections  3555  remain in contact with the release member contact surface  3126  of the housing  3100 . In some embodiments, for example, the release member  3550  and/or the extensions  3553  can be constructed from any suitable material configured to withstand deformation that may occur when exposed to a load over an extended period of time. In some embodiments, for example, the release member  3550  and/or the extensions  3553  can be constructed from brass. 
     The tapered surfaces  3557  of the projections  3555  are configured to contact tapered surfaces  3522  of contact protrusions  3515  on a proximal surface  3511  of the base  3510  (see e.g.,  FIGS. 21 and 47 ) when the base  3510  is moved proximally relative to the housing  3100 . Accordingly, when the base  3510  is moved proximally relative to the housing  3100 , the extensions  3553  are moved together by the tapered surfaces  3522  of the contact protrusions  3515 . The inward movement of the extensions  3553  causes the release member  3550  to disengage the release member contact surface  3126  of the housing  3100 , thereby allowing the release member  3550  to be moved proximally along its longitudinal axis as the spring  3576  expands. 
     The medicament delivery mechanism  3300  includes a gas container  3410 , the carrier  3370  (also referred to herein as the first movable member  3370 ), the piston member  3330  (also referred to herein as the second movable member  3330 ), and a retraction spring  3351 . As described above, the carrier  3370  and the piston member  3330  are each movably disposed within the medicament cavity  3139  of the housing  3100 . The gas container  3410  is disposed within the gas cavity  3151  of the housing  3100 . 
     The gas container  3410  includes a distal end portion  3411  and a proximal end portion  3412 , and is configured to contain a pressurized gas. The distal end portion  3411  of the gas container  3410  contains a frangible seal  3413  configured to break when the puncturer  3575  of the proximal end portion  3551  of the release member  3550  contacts the frangible seal  3413 . The gas container retention member  3580  of the proximal cap  3103  of the housing  3100  is configured to receive and/or retain the proximal end portion  3412  of the gas container  3410 . Said another way, the position of the gas container  3410  within the gas cavity  3151  is maintained by the gas container retention member  3580 . As shown in  FIGS. 18 and 19 , the length of the gas container retention member  3580  and the length of the release member  3550  collectively determine the distance between the puncturer  3575  and the frangible seal  3413  when the medical injector  3000  is in the storage configuration. Accordingly, this distance, which is the distance through which the puncturer  3575  travels when the medical injector  3000  is actuated, can be adjusted by changing the length of the gas container retention member  3580  and/or the length of the release member  3550 . In some embodiments, the actuation time and/or the force exerted by the puncturer  3575  on the frangible seal  3413  can be adjusted by changing the distance between the puncturer  3575  and the frangible seal  3413 . 
     As shown in  FIGS. 26 and 52 , the piston member  3330  includes a piston rod  3333 , and has a proximal end portion  3331  and a distal end portion  3332 . The proximal end portion  3331  includes a sealing member  3339 . The sealing member  3339  engages the sidewall of the housing  3100  to define a gas chamber (i.e., a volume within the medicament cavity  3139  between the proximal end of the housing  3100  and the proximal end of the piston member  3330 ) that receives the pressurized gas from the gas container  3410 . The sealing member  3339  can be any suitable structure and or component to produce a substantially fluid-tight seal between the sidewall of the housing  3100  and the piston member  3330 . The proximal end portion  3331  also includes a gas relief valve  3340  (see e.g.,  FIGS. 26 and 53-55 ) configured to be selectively actuated to allow fluid communication between the gas chamber and a volume outside of the gas chamber (e.g., the distal end portion of the medicament cavity  3139 ). As described in more detail below, the gas relief valve  3340  allows the gas pressure within the gas chamber to be reduced upon completion of the injection event. 
     Referring to  FIG. 27 , the distal end portion  3332  includes a first surface  3341  and a second surface  3342 . The second surface  3342  is disposed through a piston rod opening  3384  of the carrier  3370  and within the proximal end portion  3212  of the medicament container  3200 . The first surface  3341  is configured to contact a proximal surface  3378  of an engagement portion  3379  of the carrier  3370  when the medicament injector  3000  is in a first configuration (i.e., when the medicament container  3200  is in its first position). The distance between the first surface  3341  and the second surface  3342  is such that when the first surface  3341  is in contact with the engagement portion  3379  of the carrier  3370 , the second surface  3342  is spaced apart from the elastomeric member  3217  within the medicament container  3200  (see e.g.,  FIG. 27 ). This arrangement limits any preload and/or residual force applied to the piston member  3330  (e.g., via the retraction spring  3351  and/or the pressurized gas) from being transferred to the plunger  3217 . Said another way, the plunger  3217  is isolated from the piston member  3330  during the storage configuration and/or when the medicament container  3200  is moving distally within the housing  3100 . Accordingly, this arrangement reduces and/or eliminates leakage of the medicament  3220  from the medicament container  3200 . 
     As described in more detail herein, the piston member  3330  is configured to move within the medicament container  3200 . Because the first surface  3341  is configured to contact the engagement portion  3379 , the piston member  3330  applies a force to the proximal surface  3378  of the first shoulder  3377  such that the carrier  3370  and the piston member  3330  move together within the medicament cavity  3139 . Moreover, when the medicament container  3200  is in its second position, the piston member  3330  can move relative to the carrier  3370  and/or the medicament container  3200  such that the second surface  3342  engages and/or contacts the elastomeric member  3217  to convey the medicament  3220  contained in the medicament container  3200 . The piston member  3330  can be constructed of a resilient, durable and/or sealing material or combination of materials, such as a rubber. 
     The carrier  3370  of the medicament delivery mechanism  3300  includes a distal end portion  3372 , a proximal end portion  3371 , a first side portion  3373 , a second side portion  3374  and a hinge portion  3375  (see e.g.,  FIGS. 23-28 ). The first side portion  3373  includes latch protrusions  3383  configured to be coupled to the corresponding latches  3376  of the second side portion  3374 . The second side portion  3374  is configured to move relative to the first side portion  3373  via the hinge portion  3375  between an opened configuration ( FIGS. 23 and 24 ) and a closed configuration ( FIG. 25 ). This arrangement allows at least the proximal end portion  3212  of the medicament container  3200  to be disposed within (and/or removed from) the carrier  3370  when the carrier  3370  is in the opened configuration (see e.g.,  FIGS. 23 and 24 ). When the carrier  3370  is in the closed configuration (see e.g.,  FIGS. 25-28 ), the latches  3376  of the second side portion  3374  engage the latch protrusions  3383  of the first side portion  3373  to maintain the medicament container  3200  within the carrier  3370 . 
     The proximal end portion  3371  of the carrier  3370  includes a first shoulder  3377  and a second shoulder  3381  that collectively define a flange groove  3385 . The flange groove  3385  is configured to receive the flange  3214  of the proximal end portion  3212  of the medicament container  3200  (see e.g.,  FIG. 26 ). More particularly, the first shoulder  3377  is defined by the first side portion  3373 , and the second shoulder  3381  is defined by portions of both the first side portion  3373  and the second side portion  3374 . In this manner, the first shoulder  3377  is configured to contact a proximal surface of the flange  3214 , either directly or via intervening structure (e.g., an o-ring, a damping member, or the like). Similarly, the second shoulder  3381  is configured to contact a distal surface of the flange  3214 , either directly or via intervening structure (e.g., an o-ring, a damping member, or the like). In this manner, as described in more detail below, the first shoulder  3377  can transfer at least a portion of a distal force (i.e., an insertion force) to the flange  3214  to produce distal movement of the carrier  3370  and/or the medicament container  3200  within the housing  3100 . The second shoulder  3381  can transfer at least a portion of a proximal force (i.e., a retraction force) to the flange  3214  to produce proximal movement of the carrier  3370  and/or the medicament container  3200  within the housing  3100 . 
     The second side portion  3374  includes a protrusion  3386  configured to contact a surface of the first side portion  3373  when the carrier  3370  is in the closed configuration ( FIG. 25 ). In this manner, the protrusion  3386  and the corresponding portion of the first side portion  3373  limits the movement of the second side portion  3374  relative to the first side portion  3373  when the carrier  3370  is in the closed configuration. Similarly stated, the protrusion  3386  of the second side portion  3374  contacts the first side portion  3373  to prevent the carrier  3370  from squeezing the medicament container  3200 , when the carrier  3370  is in the closed configuration. 
     The second side portion  3374  includes a latch  3387  having a protrusion  3388 . The protrusion  3388  of the latch  3387  is configured to engage a retraction lock protrusion  3162  defined by the sidewall of the housing  3100  defining the medicament cavity  3139  (see e.g.,  FIG. 28 ) when the carrier  3370  and the medicament container  3200  are in the first (i.e., storage) position. This arrangement allows the medicament delivery mechanism  3300  (e.g., the carrier  3370 , the piston member  3330 ) and the medicament container  3200  to move in the distal direction within the housing  3100  but limits the movement of the carrier  3370  and the medicament container  3200  in the proximal direction. In this manner, the preload of the retraction spring  3351  is not transferred to the piston member  3330  and/or the engagement portion  3379  of the carrier  3370 . Similarly stated, this arrangement prevents the medicament delivery mechanism  3300  from moving in the proximal direction when the medical injector  3000  is in the first configuration. This arrangement also limits proximal motion of the medicament delivery mechanism  3300  during assembly (e.g., when the needle sheath is being pressed about the needle). 
     As described above, the carrier  3370  includes the engagement portion  3379  configured to engage the first surface  3341  of the piston member  3330 . The first shoulder  3377  is in contact with the proximal surface of the flange  3214  and therefore transmits a force from the piston member  3330  to move the medicament container  3200  from a first position to a second position when the medicament injector  3000  is actuated. 
     As shown in  FIG. 26 , the carrier  3370  also includes an engagement portion  3382  configured to engage the retraction spring  3351 . Although the engagement portion  3382  is shown as including a protrusion about which a portion of the retraction spring  3351  is disposed, in other embodiments, the engagement portion  3382  can include any suitable features for engaging and/or retaining the retraction spring  3351  (e.g., a recess). The second shoulder  3381  is configured to engage the distal end of the flange  3214  and therefore transmits a retraction force produced by the retraction spring  3351  to move the medicament container  3200  from the second position toward the first position. 
     A proximal surface  3378  of the first shoulder  3377  of the carrier  3370  includes a gas valve actuator  3380 . The gas valve actuator  3380  is configured to engage the gas relief valve  3340  (see e.g.,  FIG. 26 ) of the piston member  3330  to allow the pressurized gas contained within the gas chamber (i.e., the volume within the medicament cavity  3139  between the proximal end of the housing  3100  and the proximal end of the piston member  3330 ) to escape when the injection event is complete. Thus, after the gas pressure within the medicament cavity  3139  decreases below a certain level, the force exerted by the retraction spring  3351  on the carrier  3370  is sufficient to cause the carrier  3370  to move proximally within the housing  3100  (i.e., to retract). In addition, this arrangement results in there being substantially no residual force (from the pressurized gas) within the housing, which decreases stress on the components after the injection event. 
       FIGS. 29-39  show the electronic circuit system  3900 . The electronic circuit system  3900  of the medical injector  3000  includes an electronic circuit system housing  3170 , a printed circuit board  3922 , a battery assembly  3962 , an audio output device  3956 , two light emitting diodes (LEDs)  3958 A,  3958 B and a battery clip  3910 . As shown in  FIG. 36 , the electronic circuit system  3900  is disposed within the electronic circuit system cavity  3137  of the housing  3100 . As described herein, the electronic circuit system  3900  is configured to output an electronic output associated with the use of the medical injector  3000 . 
     The electronic circuit system housing  3170  of the electronic circuit system  3900  includes a distal end portion  3172  and a proximal end portion  3171 . The proximal end portion  3171  includes connection protrusions  3174 A and a battery clip protrusion  3176  (see e.g.,  FIG. 33 ). The connection protrusions  3174 A are configured to matingly engage a surface of the sidewalls of the housing  3100  that define the electronic cavity  3137 , as described above. In this manner, the electronic circuit system  3900  can be coupled to the housing  3100  within the electronic circuit system cavity  3137 . In other embodiments, the electronic circuit system  3900  can be coupled to the housing  3100  by other suitable means such as an adhesive, a clip, a label and/or the like. As described in more detail herein, the battery clip protrusion  3176  is configured to hold the battery clip  3910  in place. 
     The proximal end portion  3171  of the electronic circuit system housing  3170  defines multiple sound apertures  3173 . The audible output device  3956  is disposed against the proximal end portion  3171  of the electronic circuit system housing  3170  such that the front face of the audible output device  3956  is disposed adjacent the sound apertures  3173 . In this manner, the sound apertures  3173  are configured to allow sound produced by the audio output device  3956  to pass from the audio output device  3956  to a region outside of the housing  3100 . 
     As shown in  FIGS. 32 and 33 , the distal end portion  3172  of the electronic circuit system housing  3170  includes the connection protrusion  3174 B, a stiffening protrusion  3177  and defines an LED aperture  3178 , apertures  3175 , a safety lock actuator groove  3179  and a base actuator groove  3180 . The LED aperture  3178  is configured to receive the LEDs  3958 A,  3958 B such that a user can view the LEDs  3958 A,  3958 B, which are described in more detail herein. 
     The connection protrusion  3174 B extends from the distal end portion  3172  of the electronic circuit system housing  3170 , and is configured to attach the electronic circuit system  3900  to the housing  3100 , as described above. The stiffening protrusion  3177  is configured to have at least a portion received within and/or accessible via the apertures  3175  defined by the housing  3100  (see e.g.,  FIG. 11 ). The stiffening protrusion  3177  is configured to limit the bending (e.g., buckling) of the electronic circuit system housing  3170  when the electronic circuit system housing  3170  is coupled to the housing  3100 . Moreover, a user can access the stiffening protrusion  3177  via the apertures  3175 . In this manner, for example, the user can disengage the stiffening protrusion  3177  from the apertures  3175 . 
     The safety lock actuator groove  3179  of the electronic circuit system housing  3170  is configured to be disposed adjacent the safety lock actuator groove  3133  of the distal end portion  3102  of the housing  3100 . In this manner, the safety lock actuator groove  3179  of the electronic circuit system housing  3170  and the safety lock actuator groove  3133  of the distal end portion  3102  of the housing  3100  collectively receive the actuator  3724  of the safety lock  3700 , which is described in more detail herein. Similarly, the base actuator groove  3180  of the electronic circuit system housing  3170  is configured to be disposed adjacent the base actuator groove  3132  of the distal end portion  3102  of the housing  3100 . The base actuator groove  3180  of the electronic circuit system housing  3170  and the base actuator groove  3132  of the distal end portion  3102  of the housing  3100  collectively receive the protrusion  3520  of the base  3510 , which is described in more detail herein. 
     The printed circuit board  3922  of the electronic circuit system  3900  includes a substrate  3924 , a first actuation portion  3926  and a second actuation portion  3946 . The substrate  3924  of the printed circuit board  3922  includes the electrical components for the electronic circuit system  3900  to operate as desired. For example, the electrical components can be resistors, capacitors, inductors, switches, microcontrollers, microprocessors and/or the like. The printed circuit board may also be constructed of materials other than a flexible substrate such as a FR4 standard board (rigid circuit board). 
     As shown in  FIGS. 37-39 , the first actuation portion  3926  includes a first electrical conductor  3934  and defines an opening  3928  having a boundary  3929 . The opening  3928  of the first actuation portion  3926  is configured to receive a protrusion  3726  of the actuator  3724  of the safety lock  3700 . The boundary  3929  of the first opening  3928  has a discontinuous shape, such as, for example, a teardrop shape, that includes a stress concentration riser  3927 . The discontinuity and/or the stress concentration riser  3927  of the boundary  3929  can be of any suitable shape to cause the substrate  3924  to deform in a predetermined direction when the protrusion  3726  of the actuator  3724  of the safety lock  3700  is moved relative to the opening  3928 , as shown by the arrow GG in  FIG. 38 . 
     The opening  3928  is defined adjacent the first electrical conductor  3934  that electronically couples the components included in the electronic circuit system  3900 . The first electrical conductor  3934  includes a first switch  3972 , which can be, for example a frangible portion of the first electrical conductor  3934 . In use, when the safety lock  3700  is moved from a first position (see e.g.,  FIG. 37 ) to a second position (see e.g.,  FIG. 38 ), the actuator  3724  moves in a direction substantially parallel to a plane defined by a surface of the first actuation portion  3926  of the substrate  3924 . The movement of the actuator  3724  causes the protrusion  3726  to move within the first opening  3928 , as indicated by the arrow GG in  FIG. 38 . The movement of the protrusion  3726  tears the first actuation portion  3926  of the substrate  3924 , thereby separating the portion of the first electrical conductor  3934  including the first switch  3972 . Said another way, when the safety lock  3700  is moved from its first position to its second position (see e.g.,  FIG. 50 ), the actuator  3724  moves irreversibly the first switch  3972  from a first state (e.g., a state of electrical continuity) to a second state (e.g., a state of electrical discontinuity). Said yet another way, when the safety lock  3700  is moved from its first position to its second position, the actuator  3724  disrupts the first electrical conductor  3934 . 
     The second actuation portion  3946  includes a second electrical conductor  3935  and defines an opening  3945 , having a boundary  3949  and a tear propagation limit aperture  3948 . As shown in  FIGS. 36-39 , the opening  3945  of the second actuation portion  3946  is configured to receive a portion of an actuator  3520  of the base  3510 . The boundary  3949  of the opening  3945  has a discontinuous shape that includes a stress concentration riser  3947 . The discontinuity and/or the stress concentration riser  3947  of the boundary  3949  can be of any suitable shape to cause the substrate  3924  to deform in a predetermined direction when the actuator  3520  of the base  3510  is moved in a proximal direction relative to the opening  3945 , as shown by the arrow HH in  FIG. 39 . 
     The second electrical conductor  3935  includes a second switch  3973  disposed between the opening  3945  and the tear propagation limit aperture  3948 , which can be, for example, a frangible portion of the second electrical conductor  3935 . In use, when the base  3510  is moved from its first position to its second position (see e.g.,  FIG. 51 ), the actuator  3520  moves in a proximal direction, substantially parallel to a plane defined by a surface of the second actuation portion  3946  of the substrate  3924 . The proximal movement of the actuator  3520  tears the second actuation portion  3946  of the substrate  3924 , thereby separating the portion of the second electrical conductor  3935  including the second switch  3973 . Said another way, when the base  3510  is moved from its first position to its second position, the actuator  3520  moves irreversibly the second switch  3973  from a first state (e.g., a state of electrical continuity) to a second state (e.g., a state of electrical discontinuity). The tear propagation limit aperture  3948  is configured to limit the propagation of the tear in the substrate  3924  in the proximal direction. Said another way, the tear propagation limit aperture  3948  is configured to ensure that the tear in the substrate  3924  does not extend beyond the tear propagation limit aperture  3948 . The tear propagation limit aperture  3948  can be any shape configured to stop the propagation of a tear and/or disruption of the substrate  3924 . For example, the tear propagation limit aperture  3948  can be oval shaped. In other embodiments, the proximal boundary of the tear propagation limit aperture  3948  can be reinforced to ensure that the tear in the substrate  3924  does not extend beyond the tear propagation limit aperture  3948 . 
     In some embodiments, the safety lock  3700  and base  3510  can be configured to interact with mechanical and/or optical switches to produce an electronic output in a reversible manner. 
     The battery assembly  3962  of the electronic circuit system  3900  includes two batteries stacked on top of one another. In other embodiments, the electronic circuit system can include any number of batteries and/or any suitable type of power source. In some embodiments, for example, the battery assembly can include Lithium batteries such as, for example, CR1616, CR2016s, type AAA or the like. The battery assembly  3962  has a first surface  3964  and a second surface  3966 . The first surface  3964  of the battery assembly  3962  can contact an electrical contact (not shown) disposed on the substrate  3924 . The second surface  3966  of the battery assembly  3962  is configured to contact a contact portion  3918  of a distal end portion  3916  of a battery clip  3910 . When both the electrical contact of the substrate  3924  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910  contact the battery assembly  3962 , the batteries of the battery assembly  3962  are placed in electrical communication with the electronic circuit system  3900 . Said another way, when the electrical contact of the substrate  3924  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910  contact the battery assembly  3962 , the battery assembly  3962  is configured to supply power to the electronic circuit system  3900 . 
     The battery clip  3910  (shown in  FIG. 34 ) includes a proximal end portion  3912  and a distal end portion  3916 . The proximal end portion  3912  defines a retention aperture  3913 . The retention aperture  3913  is configured to receive a screw  3911  to couple the battery clip  3910  to the battery clip protrusion  3176  of the electronic circuit system housing  3170 . In this manner, the battery clip protrusion  3176  maintains the position of the battery clip  3910  with respect to the electronic circuit system housing  3170  and/or the battery assembly  3962 . 
     The distal end portion  3916  of the battery clip  3910  includes a contact portion  3918  and an angled portion  3917 . As described above, the contact portion  3918  is configured to contact the second surface  3966  of the battery assembly  3962  to place the battery assembly  3962  in electrical communication with the electronic circuit system  3900 . The angled portion  3917  of the distal end portion  3916  of the battery clip  3910  is configured to allow a proximal end portion  3236  of a battery isolation protrusion  3197  (see e.g.,  FIG. 41 ) to be disposed between the second surface  3966  of the battery assembly  3962  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910 . When the battery isolation protrusion  3197  is disposed between the second surface  3966  of the battery assembly  3962  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910 , the electrical path between the battery assembly  3962  and the remainder of the electrical circuit system  3900  is disrupted, thereby removing power from the electronic circuit system  3900 . The contact portion  3918  of the distal end portion  3916  of the battery clip  3910  is biased such that when the battery isolation protrusion  3197  is removed, the contact portion  3918  will move into contact the second surface  3966  of the battery assembly  3962 , thereby restoring electrical communication between the battery assembly  3962  and the electronic circuit system  3900 . In some embodiments, the battery isolation protrusion  3197  can be repeatedly removed from between the second surface  3966  of the battery assembly  3962  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910  and reinserted. Said another way, the battery isolation protrusion  3197  and the battery clip  3910  collectively form a reversible on/off switch. 
     The audio output device  3956  of the electronic circuit system  3900  is configured to output audible sound to a user in response to use of the medical injector  3000 . In some embodiments, the audible output device  3956  can be a speaker. In some embodiments, the audible sound can be, for example, associated with a recorded message and/or a recorded speech. In other embodiments, the audible instructions can be an audible beep, a series of tones and/or or the like. 
     In other embodiments, the medical injector  3000  can have a network interface device (not shown) configured to operatively connect the electronic circuit system  3900  to a remote device (not shown) and/or a communications network (not shown). In this manner, the electronic circuit system  3900  can send information to and/or receive information from the remote device. The remote device can be, for example, a remote communications network, a computer, a compliance monitoring device, a cell phone, a personal digital assistant (PDA) or the like. Such an arrangement can be used, for example, to download replacement processor-readable code from a central network to the electronic circuit system  3900 . In some embodiments, for example, the electronic circuit system  3900  can download information associated with a medical injector  3000 , such as an expiration date, a recall notice, updated use instructions or the like. Similarly, in some embodiments, the electronic circuit system  3900  can upload information associated with the use of the medical injector  3000  via the network interface device (e.g., compliance information or the like). 
       FIGS. 40 and 41  show the cover  3190  of the medical injector  3000 . The cover  3190  includes a proximal end portion  3191  and a distal end portion  3192 , and defines a cavity  3196 . The cavity  3196  of the cover  3190  is configured to receive at least a portion of the housing  3100 . Thus, when the portion of the housing  3100  is disposed within the cover  3190 , the cover  3190  blocks an optical pathway between the medicament container  3200  and a region outside of the housing  3100 . Similarly stated, when the portion of the housing  3100  is disposed within the cover  3190 , the cover  3190  obstructs the first status indicator aperture  3130  and/or the second status indicator aperture  3160  of the housing  3100  to reduce the amount of light transmitted to the medicament  3220  within the medicament container  3200 . In this manner, the life of the medicament  3220  can be extended by the prevention and/or reduction of degradation to the medicament  3220  that may be caused by ultra-violet radiation. In other embodiments, however, such those containing a medicament that is not sensitive to ultraviolet (UV) radiation, the cover  3190  can include viewing windows and/or openings that substantially correspond to the aperture  3130  and/or the aperture  3160 . 
     The proximal end portion  3191  of the cover  3190  defines apertures  3193  configured to receive the cover retention protrusions  3104  of the housing  3100  (shown in  FIGS. 10 and 12 ). In this manner, the apertures  3193  and the cover retention protrusions  3104  of the housing  3100  removably retain the cover  3190  about at least a portion of the housing  3100 . Said another way, the apertures  3193  and the cover retention protrusions  3104  of the housing  3100  are configured such that the cover  3190  can be removed from a portion of the housing  3100  and then replaced about the portion of the housing  3100 . 
     As described above, the electronic circuit system  3900  can be actuated when the housing  3100  is at least partially removed from the cover  3190 . More particularly, the distal end portion  3192  of the cover  3190  includes the battery isolation protrusion  3197 . The battery isolation protrusion  3197  includes a proximal end portion  3236  and a tapered portion  3237 . The proximal end portion  3236  of the battery isolation protrusion  3197  is configured to be removably disposed between the second surface  3966  of the battery assembly  3962  and the contact portion  3918  of the distal end portion  3916  of the battery clip  3910 , as described above. 
     The cover  3190  can be any suitable configuration and can include any suitable feature. For example, the cover  3190  includes openings  3195  and notches  3194 . In some embodiments, the openings  3195  can receive inserts (not shown). The inserts can be flexible inserts and can increase friction between the cover  3190  and a surface. For example, the inserts can increase the friction between the cover  3190  and a surface on which the medical injector  3000  is placed, to prevent sliding. The notches  3194  are disposed at the proximal end of the cover  3190 . In some embodiments, the notches  3194  can be used to reduce the material needed to manufacture the cover  3190 . 
       FIGS. 42-46  show the safety lock  3700  of the medical injector  3000 . The safety lock  3700  of the medical injector  3000  includes a proximal surface  3730 , a distal surface  3740  opposite the proximal surface  3730  and a needle sheath  3810 . The safety lock  3700  defines a needle sheath aperture  3703  and a battery isolation protrusion aperture  3728 . The battery isolation protrusion aperture  3728  is configured to receive the battery isolation protrusion  3197  of the cover  3190  such that the battery isolation protrusion  3197  can be disposed within the electronic circuit system cavity  3137  and/or in engagement with the electronic circuit system  3900 , as described above. Similarly stated, the battery isolation protrusion aperture  3728  of the safety lock  3700  is aligned with the battery isolation protrusion aperture  3135  of the housing  3100 , such that the battery isolation protrusion  3197  can be disposed within the electronic circuit system cavity  3137  when the cover  3190  is disposed about a portion of the housing  3100 . 
     The proximal surface  3730  of the safety lock  3700  includes a safety lock protrusion  3702 , a stopper  3727 , an actuator  3724 , two opposing pull-tabs  3710  and an engagement portion  3720 . As described above, when the safety lock  3700  is in a first (locked) position, the safety lock protrusion  3702  is configured to be disposed in the opening  3556  defined by the extensions  3553  of the distal end portion  3552  of the release member  3550  (see e.g.,  FIG. 21 ). Accordingly, the safety lock protrusion  3702  is configured to prevent the extensions  3553  from moving closer to each other, thereby preventing proximal movement of the release member  3550  and/or delivery of the medicament  3220 . The stopper  3727  of the safety lock  3700  is a protrusion extending from the proximal surface  3730  of the safety lock  3700 . The stopper  3727  is configured to contact a portion of the housing  3100  to limit the proximal movement of the safety lock  3700  relative to the housing  3100 . In other embodiments, the stopper  3727  can be any structure configured to limit the proximal movement of the safety lock  3700 . 
     The actuator  3724  of the safety lock  3700  has an elongated portion  3725  and a protrusion  3726 . The elongated portion  3725  extends in a proximal direction from the proximal surface  3730 . In this manner, the elongated portion  3725  can extend through a safety lock actuator opening  3524  of the base  3510  (see e.g.,  FIG. 47 ) and within the safety lock actuator groove  3133  of the housing  3100  and the safety lock actuator groove  3179  of the electronic circuit system housing  3170 . The protrusion  3726  extends in a direction substantially transverse to the elongated portion  3725  and/or substantially parallel to the proximal surface  3730  of the safety lock  3700 . As described above, the opening  3928  of the first actuation portion  3926  of the printed circuit board  3922  is configured to receive the protrusion  3726  of the actuator  3724  of the safety lock  3700 . 
     The pull-tabs  3710  of the safety lock  3700  include a grip portion  3712  and indicia  3713 . The grip portion  3712  of the pull-tabs  3710  provides an area for the user to grip and/or remove the safety lock  3700  from the rest of the medicament delivery system  3700 . The indicia  3713  provide instruction on how to remove the safety lock  3700 . The distal end surface  3740  also includes indicia  3741  (see e.g.,  FIG. 44 ). In some embodiments, for example, indicia can indicate the direction the user should pull the safety lock  3700  to remove the safety lock  3700 . 
     The engagement portion  3720  of the safety lock  3700  includes engagement members  3721 . The engagement members  3721  extend in a proximal direction from the proximal surface  3730 . The engagement members  3721  have tabs  3722  that extend from a surface of the engagement members  3721 . The tabs  3722  are configured to engage an outer surface  3815  of a distal end portion  3812  of the needle sheath  3810 . 
     As shown in  FIGS. 45 and 46 , the needle sheath  3810  includes the distal end portion  3812 , a proximal end portion  3811  and a rib  3816 . The needle sheath  3810  also defines a bore  3813 . The bore  3813  is defined by a contoured portion  3814  of the needle sheath  3810 , and is configured to receive the needle  3216  and/or a distal end portion of the  3213  of the medicament container  3200 . The inner portion of the needle sheath  3810  defines a friction fit with the distal end portion  3213  of the medicament container  3200 . In this manner, the needle sheath  3810  can protect the user from the needle  3216  and/or can keep the needle  3216  sterile before the user actuates the medical injector  3000 . The proximal end portion  3811  of the needle sheath is configured to contact the body  3210  of the medicament container  3200 . 
     The distal end portion  3812  of the needle sheath  3810  is configured to be inserted into a space defined between the tabs  3722  of the engagement members  3721  of the safety lock  3700 . The tabs  3722  are angled and/or bent towards the distal direction to allow the distal end portion  3812  of the needle sheath  3810  to move between the engagement members  3721  in a distal direction, but not in a proximal direction. Similarly stated, the tabs  3722  include an edge that contacts the outer surface  3815  of the needle sheath  3810  to prevent the safety lock  3700  from moving in a distal direction relative to the needle sheath  3810 . In this manner, the needle sheath  3810  is removed from the needle  3216  when the safety lock  3700  is moved in a distal direction with respect to the housing  3100  (see e.g.,  FIG. 50 ). 
       FIGS. 47 and 48  show the base (or actuator)  3510  of the medical injector  3000 . The base  3510  includes a proximal surface  3511 , a distal surface  3523  and base connection knobs  3518 . The base  3510  defines a needle aperture  3513 , a safety lock protrusion aperture  3514 , a battery isolation protrusion aperture  3521 , a safety lock actuator opening  3524  and pull-tab openings  3519 . The needle aperture  3513  is configured to receive the needle  3216  when the medical injector  3000  is actuated. The safety lock protrusion aperture  3514  of the base  3510  receives the safety lock protrusion  3702  of the safety lock  3700  when the safety lock  3700  is coupled to the housing  3100  and/or the base  3510 . The battery isolation protrusion aperture  3521  of the base  3510  receives the battery isolation protrusion  3197  of the cover  3190  and the stopper  3727  of the safety lock  3700 . The safety lock actuator opening  3524  receives the safety lock actuator  3724  of the safety lock  3700 . The pull-tab openings  3519  are configured to receive the pull-tabs  3710  of the safety lock  3700 . 
     The proximal surface  3511  of the base  3510  includes a protrusion  3520 , guide members  3517  and protrusions  3515 . The protrusion  3520  is configured to engage the substrate  3924  of the electronic circuit system  3900 . As described above, the opening  3945  of the second actuation portion  3946  of the printed circuit board  3922  is configured to receive the actuator  3520  of the base  3510 . The guide members  3517  of the base  3510  engage and/or slide within the base rail grooves  3114  of the housing  3100 , as described above. The protrusions  3515  of the base  3510  engage the tapered surfaces  3557  of the extensions  3553  of the release member  3550 . As described in further detail herein, when the safety lock  3700  is removed and the base  3510  is moved in a proximal direction with respect to the housing  3100 , the protrusions  3515  of the base  3510  are configured to move the extensions  3553  of the release member  3550  closer to each other, actuating the medicament delivery mechanism  3300 . As described above, the base connection knobs  3518  engage the base retention recesses  3134 A,  3134 B in a way that allows proximal movement of the base  3510  but limits distal movement of the base  3510 . 
     As shown in  FIG. 49 , the medical injector  3000  is first enabled by moving the medicament delivery device  3000  from a first configuration to a second configuration by moving the cover  3190  from a first position to a second position. The cover  3190  is moved from the first position to the second position by moving it with respect to the housing  3100  in the direction shown by the arrow II in  FIG. 49 . When the cover  3190  is moved with respect to the housing  3100  in the direction II, the battery isolation protrusion  3197  is removed from the area between the battery clip  3910  and the second surface  3966  of the battery assembly  3962 . In this manner, the battery assembly  3962  is operatively coupled to the electronic circuit system  3900  when the cover  3190  is removed, thereby providing power to the electronic circuit system  3900 . Similarly stated, this arrangement allows the electronic circuit system  3900  to be actuated when the cover  3190  is removed. 
     When power is provided, as described above, the electronic circuit system  3900  can output one or more predetermined electronic outputs. For example, in some embodiments, the electronic circuit system  3900  can output an electronic signal associated with recorded speech to the audible output device  3956 . Such an electronic signal can be, for example, associated with a .WAV file that contains a recorded instruction, instructing the user in the operation of the medical injector  3000 . Such an instruction can state, for example, “Remove the safety tab near the base of the auto-injector.” The electronic circuit system  3900  can simultaneously output an electronic signal to one and/or both of the LEDs  3958 A,  3958 B thereby causing one and/or both of the LEDs  3958 A,  3958 B to flash a particular color. In this manner, the electronic circuit system  3900  can provide both audible and visual instructions to assist the user in the initial operation of the medical injector  3000 . 
     In other embodiments, the electronic circuit system  3900  can output an electronic output associated with a description and/or status of the medical injector  3000  and/or the medicament  3220  contained therein. For example, in some embodiments, the electronic circuit system  3900  can output an audible message indicating the symptoms for which the medicament  3220  should be administered, the expiration date of the medicament  3220 , the dosage of the medicament  3220  or the like. 
     As described above, the medical injector  3000  can be repeatedly moved between the first configuration and the second configuration when the cover  3190  is moved repeatedly between the first position and the second position respectively. Said another way, the cover  3190  can be removed and replaced about the housing  3100  any number of times. When the cover  3190  is moved from the second position to the first position, the battery isolation protrusion  3197  is inserted between the battery clip  3910  and the second surface  3966  of the battery assembly  3962 , deactivating the electronic circuit system  3900 . When the cover is moved from the first position to the second position a second time, the electronic circuit system  3900  is once again activated. In this manner, the cover  3190  can be removed and the electronic circuit system  3900  can output an electronic output without compromising the sterility of the needle  3216 . 
     After the cover  3190  is removed from the housing  3100 , the medical injector  3000  can be moved from the second configuration ( FIG. 49 ) to a third configuration ( FIG. 50 ) by moving the safety lock  3700  from a first position to a second position. The safety lock  3700  is moved from a first position to a second position by moving the safety lock  3700  with respect to the housing  3100  in the direction shown by the arrow JJ in  FIG. 50 . When the safety lock  3700  is moved from the first position to the second position, the safety lock protrusion  3702  is removed from between the extensions  3553  of the release member  3550 , thereby enabling the medicament delivery mechanism  3300 . Moreover, as shown in  FIGS. 37 and 38 , when the safety lock  3700  is moved from the housing  3100 , the actuator  3724  of the safety lock  3700  moves in the direction GG as shown in  FIG. 38 , irreversibly moving the first switch  3972  from a first state (e.g., a state of electrical continuity) to a second state (e.g., a state of electrical discontinuity). When the actuator  3724  of the safety lock  3700  moves irreversibly the first switch  3972  of the electronic circuit system  3900  to the second state, the electronic circuit system  3900  can output one or more predetermined electronic outputs. For example, in some embodiments, a processor (not shown) can output an electronic signal associated with recorded speech to the audible output device  3956 . Such an electronic signal can be, for example, associated with a recorded message notifying the user of the status of the medical injector  3000 . Such a status message can state, for example, “If ready to use the medical injector, pull off the red safety guard.” The electronic circuit system  3900  can also simultaneously output an electronic signal to one and/or both of the LEDs  3958 A,  3958 B, thereby causing one and/or both of the LEDs  3958 A,  3958 B to stop flashing, change color or the like. 
     In some embodiments, the first actuation portion  3926  and the actuator  3724  can be configured such that the actuator  3724  must move a predetermined distance before the actuator  3724  engages the boundary  3929  of the opening  3928 . For example, in some embodiments, the actuator  3724  must move approximately 0.200 inches before the actuator  3724  engages the boundary  3929  of the opening  3928 . In this manner, the safety lock  3700  can be moved slightly without irreversibly moving the first switch  3972  of the electronic circuit system  3900  to the second state. Accordingly, this arrangement will permit the user to inadvertently and/or accidentally move the safety lock  3700  without actuating the electronic circuit system  3900 . 
     In some embodiments, the electronic circuit system  3900  can be configured to output the status message for a predetermined time period, such as, for example, five seconds. After the predetermined time period has elapsed, the electronic circuit system  3900  can output an audible message further instructing the user in the operation of the medical injector  3000 . Such an instruction can state, for example, “Place the base of the auto-injector against the patient&#39;s thigh. To complete the injection, press the base firmly against the patient&#39;s thigh.” In some embodiments, the electronic circuit system  3900  can simultaneously output an electronic signal to one and/or both of the LEDs  3958 A,  3958 B, thereby causing one and/or both of the LEDs  3958 A,  3958 B to flash a particular color. In this manner, the electronic circuit system  3900  can provide both audible and/or visual instructions to assist the user in the placement and actuation of the medical injector  3000 . In some embodiments, the electronic circuit system  3900  can be configured to repeat the instructions after a predetermined time period has elapsed. 
     As described above, in other embodiments, the medical injector  3000  can have a network interface device (not shown) configured to operatively connect the electronic circuit system  3900  to a remote device (not shown) and/or a communications network (not shown). In this manner, the electronic circuit system  3900  can send a wireless signal notifying a remote device that the safety lock  3700  of the medical injector  3000  has been removed and that the medical injector  3000  has been armed. In other embodiments, the electronic circuit system  3900  can send a wireless signal (e.g., a wireless 911 call) notifying an emergency responder that the medical injector  3000  has been armed, for example, via removal of the safety lock  3700 . 
     After the safety lock  3700  is moved from the first position to the second position, the medical injector  3000  can be moved from the third configuration ( FIG. 50 ) to a fourth configuration ( FIG. 51 ) by moving the base  3510  from a first position to a second position. Similarly stated, the medical injector  3000  can be actuated by the system actuator assembly  3500  by moving the base  3510  proximally relative to the housing  3100 . The base  3510  is moved from its first position to its second position by placing the medical injector  3000  against the body of the patient and moving the base  3510  with respect to the housing  3100  in the direction shown by the arrow KK in  FIG. 51 . Moving the base  3510  from the first position to the second position causes the protrusions  3515  on the proximal surface  3511  of the base  3510  to engage the tapered surfaces  3557  of the extensions  3553  of the release member  3550 , thereby moving the extensions  3313  together. The inward movement of the extensions  3553  causes engagement surface  3554  of the release member  3550  to become disengaged from the base release surface  3126  of the housing  3100 , thereby allowing the release member  3550  to be moved proximally along its longitudinal axis as the spring  3576  expands. 
     When the base  3510  is moved from the first position to the second position, the system actuator assembly  3500  actuates the medicament delivery mechanism  3300 , thereby placing the medical injector  3000  in its fourth configuration (i.e., the needle insertion configuration), as shown in  FIGS. 51 and 52 . More particularly, when the medical injector  3000  is in its fourth configuration, the puncturer  3575  of the release member  3550  is in contact with and/or disposed through the frangible seal  3413  of the gas container  3410 . 
     After the frangible seal  3413  has been punctured, an actuating portion of a compressed gas flows from the gas container  3410 , via the gas passageway  3156  and into the medicament cavity  3139 . The gas applies gas pressure to the piston member  3330  causing the piston member  3330  and the carrier  3370  to move in a distal direction within the medicament cavity  3139 , as shown by the arrow LL in  FIG. 52 . When the carrier  3370  moves distally within the medicament cavity  3139 , the carrier  3370  and the medicament container  3200  are in a first configuration and collectively move toward a second position. In this manner, the medicament container  3200  and the needle  3216  contemporaneously move with piston member  3330  and/or the carrier  3370  in a distal direction. The movement of the needle  3216  in a distal direction causes the distal end portion of the needle  3216  to exit the housing  3100  and enter the body of a patient prior to administering the medicament  3220 . 
     As described above, at least a portion of the force exerted by the compressed gas within the gas chamber upon the piston member  3330  is transferred to the first shoulder  3377  of the carrier  3370  by the contact between the first surface  3341  of the piston member  3330  and the engagement portion  3379  of the carrier  3370 . This arrangement further allows at least a portion of the force to be transferred to the flange  3214  of the medicament container  3200 . In this manner, the application of the force on the piston member  3330  results in the distal movement of the carrier  3370  and the medicament container  3200 . Moreover, because the distal end portion  3332  of the piston member  3330  is configured such that the second surface  3342  is spaced apart from the elastomeric member  3217  within the medicament container  3200  (see e.g.,  FIG. 27 ), the force is not transferred to the elastomeric member  3217 . In this manner, the elastomeric member  3217  is isolated from the piston member  3330  when the medicament container  3200  is moving distally within the housing  3100 , which reduces and/or eliminates injection or leakage of the medicament  3220  from the medicament container  3200  during the needle insertion operation. 
     After the carrier  3370  and/or the needle  3216  have moved within the medicament cavity  3139  a predetermined distance, the carrier  3370  and the medicament container  3200  are moved from the first configuration to a second configuration. For example, in some embodiments, the retraction spring  3351  can be fully compressed and prevent the carrier  3370  from moving further in the distal direction. In other embodiments, a portion of the medicament container  3200  and/or a portion of the carrier  3370  can contact the housing  3100  when the needle insertion operation is completed, thereby limiting further distal movement of the carrier  3370 , medicament container  3200  and/or the needle  3216 . When the distal movement of the carrier  3370  is prevented, the gas within the gas chamber continues to apply gas pressure to the piston member  3330  causing the first surface  3341  of the piston member  3330  to deform a portion of the engagement portion  3379 . Similarly stated, when the distal movement of the carrier  3370  is complete, the force applied by the pressurized gas exceeds a threshold value, thereby causing the piston member  3330  to deform the engagement portion  3379 . In this manner, the engagement portion  3379  deforms (see e.g.,  FIG. 55 ) to place the carrier  3370  in its second configuration, in which the first surface  3341  of the piston member  3330  is no longer in contact with the engagement portion  3379  and/or the first shoulder  3377 . 
     When the carrier  3370  is in the second configuration, the piston member  3330  continues to move in the distal direction relative to the carrier  3370  and/or the medicament container  3200 . Similarly stated, the piston member  3330  moves with the carrier  3370  during the insertion operation (i.e., when the carrier  3370  is in its first configuration) and the piston member  3330  moves relative to the carrier  3370  (and the medicament container  3200 ) during the injection operation (i.e., when the carrier  3370  is in its second configuration). More particularly, after the engagement portion  3379  deforms, the piston rod  3333  of the piston member  3330  moves within the piston rod opening  3384  of the carrier  3370  and within the medicament container  3200 , as shown by the arrow MM in  FIG. 53 . As the piston rod  3333  of the piston member  3330  moves within the carrier  3370  and medicament container  3200 , the second surface  3342  of the piston rod  3333  contacts the elastomeric member  3217  and generates a pressure upon the medicament  3220  contained within the medicament container  3200 , thereby allowing at least a portion of the medicament  3220  to flow out of the medicament container  3200  via the needle  3216 . The medicament  3220  is delivered to a body of a user via the medicament delivery path defined by the medicament container  3200  and the needle  3216 . 
     As shown in  FIGS. 54 and 55 , after the piston member  3330  moves a predetermined distance within the medicament container  3200 , the gas valve actuator  3380  of the carrier  3370  engages the gas relief valve  3340  (see e.g.,  FIG. 55 ) of the piston member  3330  thereby allowing the pressurized gas contained within the gas chamber (i.e., the volume within the medicament cavity  3139  between the proximal end of the housing  3100  and the proximal end of the piston member  3330 ) to escape. Similarly stated, as the gas valve actuator  3380  of the carrier  3370  engages the gas relief valve  3340  of the piston member  3330 , the pressure within the housing  3100  is reduced, thereby ending the injection event. In this manner, the pre-injection distance between the proximal end portion  3331  of the piston member  3330  and the gas valve actuator  3380  of the carrier  3370  can be adjusted to control the amount of the medicament  3220  to be injected. After the gas pressure within the medicament cavity  3139  decreases below a certain level, the force exerted by the retraction spring  3351  on the engagement portion  3382  of the carrier  3370  is sufficient to cause the carrier  3370  to move proximally within the housing  3100  (i.e., to retract). Additionally, the second shoulder  3381  engages the distal surface of the flange  3214  of the medicament container  3200  to move the medicament container  3200  proximally within the housing  3100 , as shown by the arrow NN in  FIG. 54 . 
     As described above, the protrusion  3520  of the base  3510  actuates the electronic circuit  3900  to trigger a predetermined output or sequence of outputs when the base  3510  is moved from its first position to its second position (see, e.g.,  FIGS. 35-39 ). When the protrusion  3520  is moved in a proximal direction relative to the opening  3945 , as shown by the arrow HH in  FIG. 39 , the electronic circuit system  3900  is actuated to output one or more predetermined electronic outputs. For example, in some embodiments, the electronic circuit system  3900  can output an electronic signal associated with recorded speech to the audible output device  3956 . Such an electronic signal can be, for example, associated with an audible countdown timer, instructing the user on the duration of the injection procedure. Said another way, if it takes, for example, ten seconds to complete an injection, an audible countdown timer can count from ten to zero ensuring that the user maintains the medical injector  3000  in place for the full ten seconds. In other embodiments, the electronic signal can be, for example, associated with a recorded message notifying the user that the injection is complete, instructing the user on post-injection disposal and safety procedures, instructing the user on post-injection medical treatment or the like. Such a status message can state, for example, “The injection is now complete. Please seek further medical attention from a doctor.” The electronic circuit system  3900  can also simultaneously output an electronic signal to one and/or both LEDs  3958 A,  3958 B, thereby causing one and/or both LEDs  3958 A,  3958 B to stop flashing, change color or the like, to provide a visual indication that the injection is complete. In other embodiments, the electronic circuit system  3900  can send a wireless signal notifying a remote device that the injection is complete. In this manner, a patient&#39;s compliance and/or adherence with the use of the system can be monitored. 
     In some embodiments, the second actuation portion  3946  and the protrusion  3520  of the base  3510  can be configured such that the base  3510  and/or the actuator  3520  must move a predetermined distance before the protrusion  3520  engages the boundary  3949  of the opening  3945 . For example, in some embodiments, the protrusion  3520  must move approximately 0.200 inches before the actuator  3520  engages the boundary  3949  of the opening  3945 . In this manner, the base  3510  can be moved slightly without irreversibly moving the second switch  3973  of the electronic circuit system  3900  to the second state. Accordingly, this arrangement will permit the user to inadvertently and/or accidentally move the base  3510  without actuating the electronic circuit system  3900 . 
     While specific components are discussed with respect to the medical injector  3000 , in other embodiments, some components can be modified and/or removed without substantially changing the medicament injection event. For example,  FIGS. 56-59  show a portion of a medical injector  4000 . That does not include an electronic circuit system (e.g., an electronic circuit system substantially similar to the electronic circuit system  3900  included in the medical injector  3000 ). In some embodiments, the electronic circuit system can be removed to limit the cost of the medical injector  4000 . In those embodiments devoid of an electronic circuit system, for example the medical injector  4000  shown in  FIGS. 56 and 57 , the medical injector  4000  can still include components and/or portions configured to engage and/or interact with an electronic circuit system. For example, the medical injector  4000  includes a battery isolation protrusion  4197  of a cover  4190 . In this manner, the cost of production and tooling can be reduced by reducing the number of component variations. Additionally, an electronic circuit system (e.g., similar to the electronic circuit system  3900  included in the medical injector  3000 ) can be easily added to the medical injector  4000  and disposed within an electronic circuit system cavity  4137  defined by the housing  4100 . 
     The medical injector  4000  is similar to the medical injector  3000  described above. As shown in  FIGS. 56 and 57 , the medical injector  4000  includes a housing  4100 , the cover  4190  ( FIG. 56 ), a safety lock  4700  ( FIG. 56 ), a base  4510 , a system actuator assembly  4500 , a delivery mechanism  4300 , a medicament container  4200  and a needle guard assembly  4800 . The structure and operation of the cover  4190 , the safety lock  4700  and the base  4510  are similar to the structure and operation of the cover  3190 , the safety lock  3700  and the base  3510 , respectively. Accordingly, only the delivery mechanism  4300 , the system actuator assembly  4500  and the needle guard assembly  4800  are described in detail below. 
     As shown in  FIG. 56 , the housing  4100  has a proximal end portion  4101  and a distal end portion  4102 . The housing  4100  defines a gas cavity  4151 , a medicament cavity  4139  and the electronic circuit system cavity  4137 . The gas cavity  4151 , medicament cavity  4139  and the electronic circuit system cavity  4137  of the housing  4100  of the medical injector  4000  are similar to the gas cavity  3151 , the medicament cavity  3139  and the electronic circuit system cavity  3137 , shown and described above with reference to  FIGS. 15 and 16 . 
     The distal end portion  4102  of the housing  4100  is similar to the distal end portion  3102  of the housing  3100 , described above in reference to  FIG. 15 . The proximal end portion  4101  includes a proximal cap  4103 . The proximal cap  4103  includes a gas container retention member  4580  and defines a gas passageway (not shown in  FIGS. 56 and 57 ). The gas container retention member  4580  is configured to receive a gas container  4410 . The gas container retention member  4580  extends from a distal surface of the proximal cap  4103  and is configured to place a proximal end  4411  of the gas container adjacent to the proximal cap  4103 . Similarly stated, the gas container retention member  4580  extends a given distance from the proximal cap  4103  such that the gas container  4410  is disposed adjacent to the proximal cap  4103  within a proximal end of the gas cavity  4151 . In this manner, the gas container retention member  4580  differs from the gas container retention member  3580 , which positions the gas container  3410  apart from the proximal cap  3103 . 
     The system actuator assembly  4500  includes the base  4510 , a release member  4550  and a spring  4576 . The release member  4550  has a proximal end portion  4551  and a distal end portion  4552 , and is movably disposed within the gas cavity  4151 . The proximal end portion  4551  and the distal end portion  4552  of the release member  4550  are similar to the corresponding structure of the release member  3550  of the medical injector  3000 , described above with reference to  FIGS. 18-21 . The release member  4550  differs from the release member  3550 , however, in that the release member  4550  is substantially longer than the length of the release member  3550  of the medical injector  3000 . In this manner, the release member  4550  is able to engage the gas container  4410  disposed at the proximal end of the gas cavity  4151 . Similarly stated, with the gas container  4410  disposed at the proximal end of the gas cavity  4151 , the length of the release member  4550  is increased, compared to the release member  3550  of the medical injector  3000 , so that the release member  4550  can engage the gas container  4410 . Consequently, the length of the spring  4576  (in the compressed state) is longer than the length of the spring  3576  included in the medical injector  3000 , described above with reference to  FIGS. 18-21 . 
     The arrangement of the system actuator assembly  4500 , the gas container  4410  and the gas container retention member  4580  function similar to the system actuator assembly  3500 , the gas container  3410  and the gas container retention member  3580 , respectively, to activate the delivery mechanism  4300 . In some embodiments, the gas container retention member  4580  can be configured to place the gas container  4410  at any suitable position within the gas cavity  4151 . In this manner, the length of the release member  4550  and the spring  4576  can be any given length such that the proximal end portion  4551  of the release member can engage the gas container  4410 , as shown in  FIG. 57 . 
     The medicament delivery mechanism  4300  includes a carrier  4370  (also referred to herein as the “first movable member”  4370 ) and a piston member  4330  (also referred to herein as the “second movable member”  4330 ). The carrier  4370  is similar to the carrier  3370  included in the medical injector  3000  and is movably disposed within the medicament cavity  4139 . Therefore, the carrier  4370  is not described in detail herein. 
     The piston member  4330  includes a proximal end portion  4331 , a distal end portion  4332  and a piston rod  4333 . The piston portion  4330  is movably disposed within the medicament cavity  4139 . The proximal end portion  4331  includes a sealing member  4339  and is similar in form and function to the proximal end portion  3331  of piston member  3330  of the medical injector  3000  described above. The distal end portion  4332  includes a first surface  4341 , a second surface  4342  and an elongate protrusion  4343 . The second surface  4342  and the elongate protrusion  4343  are disposed within a portion of the carrier  4370  and within the medicament container  4200 . The first surface  4341  is configured to contact an engagement portion  4379  of the carrier  4370  when the medicament container  4200  is in a first configuration to maintain a given distance between the second surface  4342  and an elastomeric member  4217  of the medicament container  4200  (see e.g.,  FIG. 56 ), in a similar manner as described above. The elongate protrusion  4343  is configured to be disposed within a channel  4218  defined by the elastomeric member  4217 . Similarly stated, the piston portion  4330  includes a portion and/or surface in contact with the elastomeric member  4217  and a portion and/or surface not in contact with the elastomeric member  4217 , when the carrier  4370  is in the first configuration. In some embodiments, the elongate protrusion  4343  can be used to align the piston rod  4333  with the elastomeric member  4217  disposed within the medicament container  4200 . 
     The piston member  4330  is configured to move within the housing  4100  (e.g., in response to the release of a pressurized gas). When the piston member  4330  moves, the first surface  4341  of the piston portion  4330  can apply a force to a portion of the carrier  4370  such that the carrier  4370  and the piston portion  4330  move together within the medicament cavity  4139 . As described above, after the carrier  4370  is placed in its second (or deformed) configuration, the piston rod  4333  can move relative to the carrier  4370  and the elongate  4343  and the second surface  4342  can engage the elastomeric member  4217  to convey the medicament  4220  contained in the medicament container  4200  (see e.g.,  FIG. 57 ). 
     As shown in  FIGS. 58 and 59 , the medicament container  4200  is configured to be disposed within the carrier  4370 . The medicament container  4200  includes a proximal end portion  4212  and a distal end portion  4213 . The proximal end portion  4212  includes a flange  4214 . The distal end portion  4213  is in fluid communication with a needle  4216  (see e.g.,  FIG. 59 ). The form and function of the medicament container  4200  is similar to the form and function of the medicament container  3200  of the medical injector  3000 . The medicament container  4200  also includes a damping member  4240  disposed at a distal surface of the flange  4214 . 
     The flange  4214  of the medicament container  4200  is disposed with in a flange groove  4385  defined by a first shoulder  4377  and a second shoulder  4381  of the carrier  4370 . The flange groove  4385  includes a portion configured to receive the damping member  4240 . In this manner, the damping member  4240  is configured to dampen a portion of a retraction force applied to the flange  4214  of the medicament container  4200  by the second shoulder  4381 . The arrangement of the damping member  4240  within the flange groove  4381  reduces the likelihood of the flange  4214  breaking under the force applied by the second shoulder  4381 , which can prevent the retraction of the medicament container  4200 . 
     The needle guard assembly  4800  includes an inner needle sheath  4810  and an outer needle sheath  4820 . The inner needle sheath  4810  includes an outer surface  4815  that has a ring  4816 . The inner needle sheath  4810  is disposed within the outer needle sheath  4820  (see e.g.,  FIGS. 58 and 59 ). The inner needle sheath  4810  is similar to the needle sheath  3810  of the medical injector  3000 , described above with reference to  FIG. 46 . Therefore, details of the inner needle sheath  4810  are not described in detail herein. 
     The outer needle sheath  4820  includes a proximal end portion  4821  and a distal end portion  4822 , and defines a lumen  4826  therebetween. The lumen  4826  is configured to receive the inner needle sheath  4810 . The proximal end portion  4821  includes an inner sheath aperture  4823  configured to receive the ring  4816  of the inner needle sheath  4810 . The ring  4816  extends from the outer surface  4815  of the inner needle sheath  4810  and a portion of the ring is disposed within the inner sheath aperture  4823 . The arrangement of the ring  4816  of the inner needle sheath  4810  and the inner sheath aperture  4823  prevent the movement of the inner needle sheath  4810  within the outer needle sheath  4810 . 
     The distal end portion  4822  includes a neck  4824  that has a rib  4825 . The neck  4824  of the distal end portion  4822  is configured to contact engagement members  4721  of the safety lock  4700 . Similarly stated, the neck  4824  of the distal end portion  4822  is disposed within a space defined between the engagement members  4721  of the safety lock  4700 . The engagement members  4721  allow the distal end portion  4822  of the outer needle sheath  4820  to move between the engagement members  4721  in a distal direction, but not in a proximal direction. Similarly stated, the engagement members  4721  include an edge that contacts the rib  4825  of the outer needle sheath  4820  such as to prevent the safety lock  4700  from moving in a distal direction relative to the outer needle sheath  4820 . Said another way, the needle guard assembly  4800  is removed from the needle  4216  when the safety lock  4700  is moved in a distal direction with respect to the housing  4100  (similar to the result as shown for the medical injector  3000  in  FIG. 50 ). 
     The function of the medical injector  4000  is substantially similar to the function of the medical injector  3000 , described with reference to  FIGS. 9-55 . In this manner, the user of the medical injector  4000  can actuate the medical injector  4000  to inject a medicament, disposed within the medicament container  4200 , into an injection site of a patient. 
     Although the medicament injector  3000  and the medical injector  4000  are shown and described above as including a system actuation including the release of a pressurized gas, in other embodiments, a medicament delivery device can include any suitable method of delivery of a medicament disposed within. For example,  FIGS. 60-98  show a medical injector  5000 , according to an embodiment that includes a mechanical energy storage member, rather than a compressed gas container.  FIGS. 60-61  are perspective views of the medical injector  5000  in a first configuration (i.e., prior to use). The medical injector  5000  includes a housing  5100  (see e.g.,  FIGS. 62-70 ), a system actuator  5500  (see e.g.,  FIGS. 71-73 ), a medicament container  5200  containing a medicament  5220  (see e.g.,  FIG. 74 ), a medicament delivery mechanism  5300 , a transfer member  5600  (see e.g.,  FIG. 75-80 ), a cover  5190  (see e.g.,  FIGS. 81-82 ), and a safety lock  5700  (see e.g.,  FIGS. 83-87 ). A discussion of the components of the medical injector  5000  will be followed by a discussion of the operation of the medical injector  5000 . 
     As shown in  FIGS. 62-70 , the housing  5100  includes a first housing member  5110  ( FIGS. 66 and 67 ) and a second housing member  5140  ( FIGS. 68 and 69 ) that can couple to form the housing  5100 . The housing  5100  has a proximal end portion  5101  and a distal end portion  5102 . The housing  5100  defines a first status indicator aperture  5130  (defined by the first housing member  5110 ) and a second status indicator aperture  5160  (defined by the second housing member  5140 ). The status indicator apertures  5130 ,  5160  can allow a patient to monitor the status and/or contents of the medicament container  5200  contained within the housing  5100 . For example, by visually inspecting the status indicator aperture  5130  and/or  5160 , a patient can determine whether the medicament container  5200  contains a medicament  5220  and/or whether the medicament  5220  has been dispensed. 
     As shown in  FIGS. 66-67 , the first housing member  5110  includes an outer surface  5113  and an inner surface  5116 , and a proximal end portion  5111  and a distal end portion  5112 . The outer surface  5113  includes cover retention protrusions  5104  at the proximal end portion  5111  of the first housing member  5110  (see e.g.,  FIGS. 61, 62 and 66 ). The cover retention protrusions  5104  are configured to be received within corresponding openings  5193  defined by the cover  5190  to retain the cover  5190  about the housing  5100 . In this manner, as described in more detail herein, the cover  5190  is removably coupled to and disposed about at least a portion of the housing  5100 . 
     The outer surface  5113  defines base retention recesses  5134 A and  5134 B, an activation rod groove  5115 , and base rail grooves  5114 , at the distal end portion  5112  of the first housing member  5110 . The distal base retention recesses  5134 A are configured to receive base connection knobs  5518  of an actuator  5510  (also referred to herein as “base  5510 ,” see e.g.,  FIG. 88 ) when the base  5510  is in a first position relative to the housing  5100 . The proximal base retention recesses  5134 B are configured to receive the base connection knobs  5518  of the base  5510  when the base  5510  is in a second position relative to the housing  5100 . The base retention recesses  5134 A,  5134 B have a tapered proximal sidewall and a non-tapered distal sidewall. This allows the base retention recesses  5134 A,  5134 B to receive the base connection knobs  5518  such that the base  5510  can move proximally relative to the housing  5100 , but cannot move distally relative to the housing  5100 . Said another way, the distal base retention recesses  5134 A are configured to prevent the base  5510  from moving distally when the base  5510  is in a first position and the proximal base retention recesses  5134 B are configured to prevent the base  5510  from moving distally when the base  5510  is in a second position. Similarly stated, the proximal base retention recesses  5134 B and the base connection knobs  5518  cooperatively to limit movement of the base  5510  to prevent undesirable movement of the base  5510  after the medical injector  5000  is actuated. The proximal base retention recesses  5134 B and the base connection knobs  5518  also provide a visual cue to the user that the medical injector  5000  has been used. 
     The activation rod groove  5115  is configured to receive an activator  5530  (also referred to herein as “release member  5530 ,” see e.g.,  FIG. 88 ) of the base  5510 . As described in more detail herein, the release member  5530  of the base  5510  is configured to engage a portion of the medicament delivery mechanism  5300  when the base  5510  is moved with respect to the housing  5100 . The base rail grooves  5114  are configured to receive guide members  5517  of the base  5510 . The guide members  5517  of the base  5510  and the base rail grooves  5114  of the housing  5100  engage each other in a way that allows the guide members  5517  of the base  5510  to slide in a proximal and/or distal direction within the base rail grooves  5114  while limiting lateral movement of the guide members  5517 . This arrangement allows the base  5510  to move in a proximal and/or distal direction with respect to the housing  5100  but prevents the base  5510  from moving in a lateral direction with respect to the housing  5100 . 
     The inner surface  5116  of the first housing member  5110  includes a medicament container holder  5127 , an upper spring plate  5122  and an upper bias member plate  5123 . The inner surface  5166  also includes a series of protrusions that define a transfer member groove  5117 , piston portion grooves  5118  and a bias portion groove  5119  (see e.g.,  FIG. 67 ). The medicament container holder  5127  is configured to receive a body  5210  of the medicament container  5200  (e.g., a prefilled syringe). The medicament container holder  5127  defines a latch member notch  5120  that includes an engagement surface  5109  (see e.g.  FIG. 72 ) configured to engage a latch protrusion  5315  of a latch portion  5310  of the medicament delivery mechanism  5300 . The medicament container holder  5127  includes a proximal end surface  5108 . The proximal end surface  5108  is configured to contact a portion of the medicament container  5200  (either directly or via intervening structure, such as an o-ring or damping member) when the medicament container  5200  is in a second position, as described in further detail herein. 
     The upper spring plate  5122  is disposed at the proximal end portion  5111  of the first housing member  5110 . The upper spring plate  5122  extends from the inner surface  5116  and is configured to contact a proximal end portion  5421  of a spring  5420  (see  FIG. 91 ). In this manner, when activated, the upper spring plate  5122  limits proximal movement of the spring  5420  such that the spring expands distally to move the medicament delivery mechanism  5300  in a distal direction (see e.g.,  FIG. 93 ). Similarly stated, the upper spring plate  5122  receives a force from the spring  5420  and applies an equal and opposite reaction force to the proximal end portion  5421  of the spring  5420  such that a distal end portion  5422  of the spring  5420  expands in a distal direction, as described in further detail herein. 
     The upper bias plate  5123  is disposed at the proximal end portion  5111  of the first housing member  5110  and extends from the inner surface  5116 . The upper bias plate  5123  is configured to selectively engage a bias portion  5350  of the medicament delivery mechanism  5300  (see  FIG. 91 ). In this manner, the upper bias plate  5123  is configured to limit the proximal movement of the bias portion  5350  of the medicament delivery mechanism  5300 , as described in further detail herein. 
     As described above, the inner surface  5116  includes protrusions that define the transfer member groove  5117 , the piston portion grooves  5118  and the bias portion groove  5119 . The transfer member groove  5117  is configured to receive a guide protrusion  5619  of the transfer member  5600  (see  FIG. 80 ). The guide protrusion  5619  of the transfer member  5600  and the transfer member groove  5117  defined by the inner surface  5116  of the first housing member  5110  engage each other in a way that allows the guide protrusion  5619  of the transfer member  5600  to slide in a proximal and/or distal direction within the transfer member groove  5117  while limiting lateral movement of the guide protrusion  5619 . This arrangement allows the transfer member  5600  to move in a proximal and/or distal direction with respect to the housing  5100  but prevents the transfer member  5600  from moving in a lateral direction with respect to the housing  5100 . Similarly, the piston portion grooves  5118  are configured to receive the guide protrusions  5302  of the piston portion  5330  of the medicament delivery mechanism  5300  (see  FIG. 76 ). The bias portion groove  5119  is configured to receive the guide protrusion  5354  of the bias portion  5350  of the medicament delivery mechanism  5300  (see  FIG. 76 ). In this manner, the piston portion grooves  5118  and the bias member groove  5119  engage the guide protrusions  5302  of the piston portion  5330  and the guide protrusion  5354  of the bias portion  5350 , respectively, to prevent the medicament delivery mechanism  5300  from moving in a lateral direction with respect to the housing  5100  and/or rotating within the housing  5100 . 
     The inner surface  5116  of the first housing member  5110  further includes a transfer member release protrusion  5121 , a transfer member release support protrusion  5125 , a lower bias plate  5124 , and base lock protrusions  5126 . The transfer member release protrusion  5121  is configured to engage a latch arm  5618  of the transfer member  5600  to place the transfer member  5600  in a second configuration when the transfer member  5600  moves to a second position (see e.g.,  FIG. 97 ). Contemporaneously, the transfer member release support protrusion  5125  supports the latch arm  5618  of the transfer member  5600  as the transfer member is placed in the second configuration, as described in further detail herein. 
     The lower bias plate  5124  engages a distal end portion  5353  of the bias portion  5350  of the delivery mechanism  5300  (see e.g.,  FIG. 95 ), as described in further detail herein. The base lock protrusions  5126  are configured to engage base locks  5515  of the base  5510  when the safety lock  5700  is in contact with the medical injector  5000  (see  FIG. 73 ). Similarly stated, the safety lock  5700 , the base lock protrusions  5126 , and the base locks  5515  collectively prevent the base  5510  from moving in a proximal direction relative to the housing  5100  when the base locks  5515  of the base  5510  are in contact with the base lock protrusions  5126  of the first housing portion  5110 , as described in further detail herein. 
     The first housing member  5110  further includes a set of tabs  5128  and a set of openings  5129 . The tabs  5128  extend from portions of the inner surface  5116  of the first housing member  5110 . The first housing member  5110  can include any number of tabs  5128  that can have any suitable shape or size. For example, in some embodiments, the tabs  5128  vary in size. The tabs  5128  are configured to engage portions of the second housing member  5140  to couple the first housing member  5110  to the second housing member  5140 , as described in further detail herein. 
     As shown in  FIGS. 68-70 , the second housing member  5140  includes an outer surface  5143  and an inner surface  5146 . The second housing member  5140  also includes a proximal end portion  5141 , a proximal cap  5103 , and a distal end portion  5142 . The outer surface  5143  defines base retention recesses  5134 A and  5134 B and base rail grooves  5114 , at the distal end portion  5142  of the second housing member  5140 . The distal base retention recesses  5134 A are configured to receive base connection knobs  5518  of the base  5510  when the base  5510  is in a first position relative to the housing  5100 . The proximal base retention recesses  5134 B are configured to receive the base connection knobs  5518  of the base  5510  when the base  5510  is in a second position relative to the housing  5100 . The base retention recesses  5134 A,  5134 B have a tapered proximal sidewall and a non-tapered distal sidewall. This allows the base retention recesses  5134 A,  5134 B to receive the base connection knobs  5518  such that the base  5510  can move proximally relative to the housing  5100 , but cannot move distally relative to the housing  5100 . Said another way, the distal base retention recesses  5134 A are configured to prevent the base  5510  from moving distally when the base  5510  is in a first position and the proximal base retention recesses  5134 B are configured to prevent the base  5510  from moving distally when the base  5510  is in a second position. Similarly stated, the proximal base retention recesses  5134 B and the base connection knobs  5518  cooperatively limit movement of the base  5510  to prevent undesirable movement of the base  5510  after the medical injector  5000  is actuated. The proximal base retention recesses  5134 B and the base connection knobs  5518  also provide a visual cue to the user that the medical injector  5000  has been used. 
     The base rail grooves  5114  are configured to receive guide members  5517  of the base  5510 . The guide members  5517  of the base  5510  and the base rail grooves  5114  of the second housing member  5140  engage each other in a way that allows the guide members  5517  of the base  5510  to slide in a proximal and/or distal direction within the base rail grooves  5114  while limiting lateral movement of the guide members  5517 . This arrangement allows the base  5510  to move in a proximal and/or distal direction with respect to the housing  5100  but prevents the base  5510  from moving in a lateral direction with respect to the housing  5100 . 
     The proximal cap  5103  extends from the proximal end portion  5141  of the second housing member  5140  and encloses the proximal end portion  5101  of the housing  5100  when the first housing member  5110  is coupled to the second housing member  5140 . 
     The inner surface  5146  of the second housing member  5140  includes a medicament container holder  5157 . The inner surface further includes protrusions that define a transfer member groove  5147 , piston portion grooves  5148 , and a bias portion groove  5149 . The medicament container holder  5157  is configured to receive a body  5210  of the medicament container  5200  (e.g., a prefilled syringe). Moreover, the medicament container holder  5157  is configured to be coupled to a portion of the medicament container holder  5127  of the first housing member  5110  to define a space in which the medicament container  5200  is disposed. The medicament container holder  5157  includes a proximal end surface  5164 . The proximal end surface  5164  is configured to contact a portion of the medicament container  5200  (either directly or via intervening structure) when the medicament container  5200  is in the second position, as described in further detail herein. 
     The transfer member groove  5147  receives a latch  5620  of the transfer member  5600  (see  FIGS. 79 and 80 ). The latch  5620  of the transfer member  5600  and the transfer member groove  5147  defined by the inner surface  5146  of the second housing member  5140  engage each other in a way that allows the latch  5620  of the transfer member  5600  to slide in a proximal and/or distal direction within the transfer member groove  5147  while limiting lateral movement of the guide protrusion  5619 . Similarly, the piston portion grooves  5148  are configured to receive the guide protrusions  5302  of the piston portion  5330  of the medicament delivery mechanism  5300 . The bias portion groove  5149  is configured to receive the guide protrusion  5354  of the bias portion  5350  of the medicament delivery mechanism  5300 . In this manner, the piston portion grooves  5148  and the bias member groove  5149  engage the guide protrusions  5302  of the piston portion  5330  and the guide protrusion  5354  of the bias portion  5350 , respectively, to prevent the medicament delivery mechanism  5300  from moving in a lateral direction with respect to the housing  5100  and/or rotating within the housing  5100 . 
     The second housing member  5140  further includes a set of tab latches  5163  and defines a set of openings  5159 . The second housing member  5140  can include any number of tab latches  5163  such that the number of tab latches  5163  correspond to the number of tabs  5128  of the first housing member  5110 . Collectively, the tabs  5128  of the first housing member  5110  and the tab latches  5163  of the second housing member  5140  couple the first housing member  5110  to the second housing member  5140 . Similarly stated, the tabs  5128  are configured to engage the tab latches  5163  to define a lock fit. Moreover, a surface of the tabs  5128  is in contact with a surface of the tab latches  5163  to define a lock fit such that the first housing member  5110  and the second housing member  5140  couple together to define the housing  5100 . The openings  5129  of the first housing member  5110  and the openings  5159  of the second housing member  5140  allow access to the tabs  5128  of the first housing member  5110  and the tab latches  5163  of the second housing member  5140 , respectively. In this manner, the first housing member  5110  can be decoupled from the second housing member  5140 . 
     As shown in  FIG. 65 , when the first housing member  5110  and the second housing member  5140  are assembled, the distal end portion  5102  of the housing  5100  defines a needle aperture  5105 , a transfer member access opening  5106  and base lock openings  5131 . Similarly stated, the first housing member  5110  and the second housing member  5140  collectively define the needle aperture  5105 , the transfer member access opening  5106  and the base lock openings  5131 . The needle aperture  5105  is configured to allow the needle  5216  (see e.g.,  FIGS. 74, 92 and 93 ) to exit the housing  5100  when the medical injector  5000  is actuated, as described in further detail herein. 
     The transfer member access opening  5106  is configured to provide access to the transfer member  5600  when the transfer member  5600  is disposed within the housing  5100 . For example, in some embodiments, the transfer member  5600  can be disengaged from the medicament delivery mechanism  5300  without moving the medicament delivery mechanism  5300  in the distal direction. In this manner, the medical injector  5000  can be disabled such that the medicament delivery mechanism  5300  cannot engage the medicament container  5200  to convey a medicament  5220 . For example, in some embodiments, a user, manufacturer and/or operator can disengage the transfer member  5600  from the medicament delivery mechanism  5300 , via the transfer member access opening  5106 , to safely dispose of an unused medical injector  5000  whose medicament  5220  expired. In other embodiments, an operator can manipulate the transfer member within the housing  5100  via the transfer member access opening  5106  during the assembly of the medical injector  5000 . 
     The base lock openings  5131  are configured to receive the base locks  5515  and the safety lock protrusions  5702 , as shown in the cross-sectional view of  FIG. 73 . The base lock openings  5131  receive the base locks  5515  and the safety lock protrusions  5702  such that the base locks  5515  of the base  5510  are in contact with the base lock protrusions  5126  of the first housing member  5110  when the safety lock protrusions  5702  are disposed within the base lock openings  5131 . In this manner, the safety lock protrusions  5702  and the base lock protrusion  5126  prevent the base from moving in a proximal direction by placing the proximal surface of the base locks  5515  in contact with a distal surface of the base lock protrusions  5126 . When the safety lock protrusions  5702  are removed from the base lock openings  5131 , the proximal surface of the tapered surface of the base locks  5515  allow movement in a proximal direction past the corresponding tapered surfaces of the base lock protrusions  5126  when the base  5510  is moved in the proximal direction. 
       FIGS. 71-80  show the medicament container  5200 , the system actuator  5500 , the transfer member  5600  and the medicament delivery mechanism  5300  of the medical injector  5000 . The medicament container  5200  has a body  5210  with a distal end portion  5213  and a proximal end portion  5212 . The body  5210  defines a volume  5211  that contains (i.e., is filled with or partially filled with) a medicament  5220  (see, e.g.,  FIG. 74 ). The distal end portion  5213  of the medicament container  5200  includes a neck  5215  that is coupled to the needle  5216 , as described below. The proximal end portion  5212  of the medicament container  5200  includes an elastomeric member  5217  (i.e., a plunger) that seals the medicament  5220  within the body  5210 . The elastomeric member  5217  is configured to move within the body  5210  to inject the medicament  5220  from the medicament container  5200 . More particularly, as shown in  FIG. 78 , the elastomeric member  5217  receives a piston rod  5333  of a piston portion  5330  included in the medicament delivery mechanism  5300 . The proximal end portion  5212  includes a flange  5214  and a damping member  5240  (see  FIG. 78 ) configured to engage the piston portion  5330  and the latch portion  5310  of the medicament delivery mechanism  5300 . The flange  5214  and the damping member  5240  are also configured to engage and/or contact the medicament container holders  5127  and  5157  of the housing  5100 . 
     The elastomeric member  5217  can be of any design or formulation suitable for contact with the medicament  5220 . For example, the elastomeric member  5217  can be formulated to minimize any reduction in the efficacy of the medicament  5220  that may result from contact (either direct or indirect) between the elastomeric member  5217  and the medicament  5220 . For example, in some embodiments, the elastomeric member  5217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the medicament  5220 . In other embodiments, the elastomeric member  5217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with the medicament  5220  over a long period of time (e.g., for up to six months, one year, two years, five years or longer). In some embodiments, the elastomeric member  5217  is similar to the elastomeric member  3217  of the medical injector  3000 , described with reference to  FIG. 22 . 
     The medicament container  5200  can have any suitable size (e.g., length and/or diameter) and can contain any suitable volume of the medicament  5220 . Moreover, the medicament container  5200  and the piston portion  5330  can be collectively configured such that the piston portion  5330  travels a desired distance within the medicament container  5200  (i.e., the “stroke”) during an injection event. In this manner, the medicament container  5200 , the volume of the medicament  5220  within the medicament container  5200  and the piston portion  5330  can be collectively configured to provide a desired fill volume and delivery volume. For example, the medicament container  5200 , as shown in  FIG. 74 , is a prefilled syringe and can be purchased and/or acquired with a given fill volume. In this manner, the piston portion  5330  can be configured to provide a desired delivery volume. 
     Moreover, the length of the medicament container  5200  and the length of the piston portion  5330  can be configured such that the medicament delivery mechanism  5300  can fit in the same housing  5100  regardless of the fill volume, the delivery volume and/or the ratio of the fill volume to the delivery volume. In this manner, the same housing and production tooling can be used to produce devices having various dosages of the medicament  5220 . For example, in a first embodiment (e.g., having a fill volume to delivery volume ratio of 0.4), the medicament container has a first length and the second movable member has a first length. In a second embodiment (e.g., having a fill volume to delivery volume ratio of 0.6), the medicament container has a second length shorter than the first length, and the second movable member has a second length longer than the first length. In this manner, the stroke of the device of the second embodiment is longer than that of the device of the first embodiment, thereby allowing a greater dosage. The medicament container of the device of the second embodiment, however, is shorter than the medicament container of the device of the first embodiment, thereby allowing the components of both embodiments to be disposed within the same housing and/or a housing having the same length. 
     As shown in  FIGS. 71-74 , the system actuator  5500  includes the base  5510  and a release member  5530 , and is configured to move in the proximal and distal direction relative to the housing  5100 . Although the base  5510  and the release member  5530  are shown as being monolithically constructed to form the system actuator  5500 , in other embodiments the system actuator  5500  can include a base that is constructed separately from (and later joined to) a release member. As described above, when the medical injector  5000  is in its first configuration (i.e., the storage configuration), the base locks  5515  and the safety lock protrusions  5702  are disposed within the base lock opening  5131  such that the base locks  5515  are urged by the safety lock protrusions  5702  into contact with the base lock protrusions  5126 . Therefore, the system actuator  5500  and/or the base  5510  cannot move in the proximal direction to actuate the medicament delivery mechanism  5300 . Similarly stated, as shown in  FIG. 73 , when the medical injector  5000  is in its first configuration (i.e., the storage configuration), the safety lock protrusions  5702  and the base lock protrusions  5126  cooperatively limit the proximal movement of the base  5510 . 
     The release member  5530  has a proximal end portion  5531  and a distal end portion  5532 . The release member  5530  extends from a proximal surface  5511  of the base  5510 . The proximal end portion  5531  of the release member  5530  is configured to engage that latch portion  5310  of the medicament delivery mechanism  5300  when the medical injector is in its first (or storage) configuration. More particularly, as shown in  FIG. 72 , the proximal end portion  5531  of the release member  5530  maintains a first latch protrusion  5315  of the latch portion  5310  in contact with the engagement surface  5109  of the latch member notch  5120  of the housing  5100 . When the engagement surface  5109  is in contact with the first latch protrusion  5315 , the engagement surface  5109  applies a reaction force to the first latch protrusion  5315  in response to the force applied by the spring  5420 , which urges the transfer member  5600  and the medicament delivery mechanism  5300  in a distal direction. Similarly stated, when the first latch protrusion  5315  is in contact with the engagement surface  5109 , the engagement surface  5109  limits distal movement of the first latch protrusion  5315 , and thus, the medicament delivery mechanism  5300 . In this manner, when the system actuator  5500  is in a first position (i.e., coupled to the distal end portion of the housing  5100 ), the release member  5530  maintains the first latch protrusion  5315  within the latch member notch  5120  and maintains the medical injector  5000  in the first configuration (e.g., non-actuated configuration). 
     The medicament delivery mechanism  5300  (all or portions of which can also be referred to as a “first movable member”) includes the latch portion  5310 , the piston portion  5330  and the bias portion  5350  (see e.g.,  FIGS. 75-78 ). The latch portion  5310  is operably coupled to the spring  5420  via the transfer member  5600  (i.e., the second movable member  5600 ). The medicament delivery mechanism  5300  includes a proximal end portion  5301 . The proximal end portion  5301  includes the guide protrusions  5302 , described above with reference to  FIGS. 67-70 . 
     The latch portion  5310  includes a proximal end portion  5311  and a distal end portion  5312 . The proximal end portion  5311  is disposed at and/or joined with the proximal end portion  5301  of the medicament delivery mechanism  5300 . Similarly stated, the latch portion  5310  is configured to extend from the proximal end portion  5301  of the medicament delivery mechanism  5300  in the distal direction. The distal end portion  5312  of the latch portion  5310  includes a latch arm  5314  having a first latch protrusion  5315 , a second latch protrusion  5317 , and a second shoulder  5313 , and defines a channel  5316 . As described above, the first latch protrusion  5315  is configured to engage the release member  5530  and the engagement surface  5109  of the latch member notch  5120 . In particular, as shown in  FIG. 72 , the release member  5530  urges, bends and/or deforms the latch arm  5314  to maintain the first latch protrusion  5315  within the latch member notch  5120 . Thus, the latch arm  5314  can be constructed from a flexible material such that the release member  5530  can urge, bend and/or deform the latch arm  5314  to engage the first latch protrusion  5315  with the latch member notch  5120 . 
     The channel  5316  of the latch portion  5310  is defined between a surface of the distal end portion  5312  of the latch portion  5310  and a proximal surface  5318  of the second latch protrusion  5317 . The channel  5316  is configured to receive the latch  5620  of the transfer member  5600 . More particularly, when the medical injector  5000  is in the first configuration, the proximal surface  5318  of the second latch protrusion  5317  is in contact with a distal surface  5621  of the latch  5620  of the transfer member  5600 . In this manner, the transfer member  5600  can transfer a force produced by the actuation of the spring  5420  to the latch portion  5310  of the medicament delivery mechanism  5300  to move the medicament delivery mechanism  5300  in the distal direction. Similarly stated, this arrangement allows the medicament delivery mechanism  5300  to move with and/or remain coupled to the transfer member  5600  (which can be referred to as a “second movable member”) during the insertion and/or injection operation. 
     The piston portion  5330  includes a proximal end portion  5331  and a distal end portion  5332  and defines a piston rod  5333  therebetween. The proximal end portion  5331  is disposed at and/or joined with the proximal end portion  5301  of the medicament delivery mechanism  5300 . Similarly stated, the piston portion  5330  is configured to extend from the proximal end portion  5301  of the medicament delivery mechanism  5300  in the distal direction. The distal end portion  5332  is configured to be disposed at least partially within the proximal end portion  5212  of the medicament container  5200 . The piston rod  5333  defines recesses  5334 . 
     The piston portion  5330  includes two engagement members  5336  that have a first shoulder  5335  and a deformable portion  5338 . The engagement members  5336  are at least partially disposed within the recesses  5334  defined by the piston rod  5333 , and extend in a lateral direction relative to the piston portion  5330 . Similarly stated, the engagement members  5336  extend from the corresponding recess  5334  and are substantially perpendicular to a longitudinal axis defined by the piston portion  5330  between the proximal end portion  5331  and the distal end portion  5332 . In this manner, as described in more detail herein, when the engagement members  5336  are deformed (e.g., at the deformable portion  5338 ), the engagement members  5336  fold into and/or are contained within the recesses  5334 . The engagement members  5336  can be any suitable size or shape. In some embodiments, the engagement members  5336  can be monolithically formed with the piston portion  5330 . In other embodiments, the engagement members  5336  can be formed separately from a brittle material and later coupled to the piston portion  5330 . In still other embodiments, the engagement members  5336  can be formed separately from a flexible material and coupled to the piston portion  5330 . In some embodiments, for example, the engagement members  5336  can be a single pin that is disposed through an opening within the piston portion  5330  such that the ends of the pins protrude from the recesses  5334 . 
     The first shoulder  5335  of the engagement member  5336  is disposed at a distal surface of the engagement member  5336 . As shown in  FIG. 91 , the first shoulder  5335  is configured to engage a proximal surface of the flange  5214  of the medicament container  5200 . In this manner, the piston portion  5330  of the medicament delivery mechanism  5300  is configured to move the medicament container  5200  in response to a force applied by the spring  5420  when the medical injected  5000  is actuated. Similarly stated, when the release member  5530  actuates the medical injector  5000 , the transfer member  5600  transfers a force from the spring  5420  to the medicament delivery mechanism  5300  such that the first shoulder  5335  of the piston portion  5330  moves the medicament container  5200  from the first position to the second position. 
     The deformable portion  5338  of the engagement member  5336  is configured to deform during and/or to initiate an injection event. The deformable portion  5338  can be any suitable structure that deforms (e.g., either plastically or elastically, including bending, breaking, stretching or the like) when the force applied thereto exceeds a value. For example, in some embodiments, the deformable portion  5338  can include a fillet configured to act as a stress concentration riser configured to deform under a given force. In use within the medical injector  5000 , the deformable portion  5338  is configured to deform during and/or to initiate an injection event when the medicament container  5200  is in the second position. After deformation of the deformable portion  5338  and/or movement of the engagement members  5336 , the first shoulder  5335  is no longer in contact with the flange  5214  of the medicament container  5200  and the piston portion  5330  is allowed to move in a distal direction, relative to the medicament container  5200 . 
     The bias portion  5350  includes a proximal end portion  5352  and a distal end portion  5353 . The proximal end portion  5352  is disposed at and/or joined with the proximal end portion  5301  of the medicament delivery mechanism  5300 . Similarly stated, the bias portion  5350  is configured to extend from the proximal end portion  5301  of the medicament delivery mechanism  5300  in the distal direction. 
     The bias portion  5350  includes a serpentine portion  5355  constructed from any suitable material and having suitable dimensions such that the bias portion  5350  and/or the serpentine portion  5355  produce a force when the serpentine portion  5355  is compressed (see e.g.,  FIG. 95 ). As described above, the bias portion  5350  includes guide protrusions  5354  (see e.g.,  FIG. 76 ) configured to engage the bias member grooves  5119  defined by the first housing member  5110  and the bias member grooves  5149  defined by the second housing member  5140  to prevent the bias portion  5350  from moving in a lateral direction with respect to the housing  5100  and/or rotating within the housing  5100 . The distal end portion  5353  of the bias portion  5350  is configured to engage the lower bias plate  5124 . In this manner, a proximal surface of the lower bias plate  5124  prevents the distal end portion  5353  of the bias portion  5350  from moving in the distal direction as the medicament delivery device  5300  moves in the distal direction in response to the distal force applied by the spring  5420  when the medical injector  5000  is actuated. Therefore, the serpentine portion  5355  of the bias portion  5350  is compressed between the proximal end portion  5352  and the distal end portion  5353 . 
     The transfer member  5600  (also referred to as the “second movable member”) includes a proximal end portion  5610  and a distal end portion  5611 , and is configured to move between a first configuration (see e.g.,  FIGS. 79 and 80 ) and a second configuration (see e.g.,  FIGS. 97 and 98 ). The proximal end portion  5610  is substantially cylindrical and is configured to engage and/or contact the spring  5420 . Moreover, the transfer member  5600  includes a ring protrusion  5612  that includes a proximal surface  5613  defining a spring seat  5615 . As shown in  FIG. 72 , the distal end portion  5422  of the spring  5420  is disposed about the proximal end portion  5610  of the transfer member  5600 , and is configured to engage the spring seat  5615  defined by the ring protrusion  5612 . 
     The transfer member  5600  further includes a guide arm  5616  and the latch extension  5617  that extends from a distal surface  5614  of the ring protrusion  5612 . The guide arm  5616  is configured to guide the transfer member  5600  as it moves in the distal direction and provide support to the latch extension  5617  when the transfer member  5600  is placed in the second configuration, as described in further detail herein. 
     The latch extension  5617  includes the latch arm  5618  and a bendable portion  5622 . The latch arm  5618  includes the guide protrusion  5619  and the latch  5620 . As described above, the latch extension  5617  extends in a distal direction from the ring protrusion  5612  of the transfer member  5600 . The latch arm  5618  is configured to extend from the distal end portion  5611  of the transfer member  5610 . Similarly stated, the latch arm  5618  extends from a distal end portion of the latch extension  5617 . Moreover, the latch arm  5618  extends from the distal end portion of the latch extension  5617  at a suitable angle such that the latch  5620  is received within the channel  5316  (see e.g.,  FIG. 72 ). For example, in some embodiments, the latch arm  5618  extends from the distal end portion of the latch extension  5617  at an acute angle. The guide protrusion  5619  is configured to engage the transfer member groove  5117 , as described above. 
     The latch  5620  extends from a proximal end portion  5623  of the latch arm  5618 . The latch  5620  is configured to engage the second latch protrusion  5317  of the latch portion  5310  of the medicament delivery mechanism  5300 . As described above, the distal surface  5621  of the latch  5620  is configured to be in contact with a proximal surface  5318  of the second latch protrusion  5317  when the transfer member  5600  is in the first configuration. In this manner, the transfer member  5600  transfers a force from the actuation of the spring  5420  to the medicament delivery mechanism  5300  via the transfer member  5600  to move the medicament delivery mechanism  5300  in the distal direction within the housing  5100 . Therefore, the force produced by the spring  5420  results in both the insertion of the needle  5216  and injection of the medicament  5220  within the medicament container  5200 , which occur as separate and distinct operations, as described herein. 
     Furthermore, when the transfer member  5600  has moved a desired distance in the distal direction, in response to the force produced by the actuation of the spring  5420 , the latch arm  5618  engages the transfer member release protrusion  5121  of the housing  5100  (see e.g.,  FIG. 67 ) to place the transfer member  5600  in the second configuration. Similarly stated, the latch arm  5618  engages and/or contacts the transfer member release protrusion  5121  when the transfer member  5600  is in the second position. The bendable portion  5622  of the latch extension  5617  is configured to bend, relative to the latch extension  5617 . Thus, when the latch arm  5618  engages the transfer member release protrusion  5121 , the bendable portion  5622  of the transfer member  5600  bends, thereby placing the transfer member  5600  in its second configuration (see  FIGS. 97 and 98 ). When the transfer member  5600  is in its second configuration, the latch  5620  is disengaged from the second latch protrusion  5317  of the medicament delivery mechanism  5300 . Said another way, when the latch arm  5618  engages the transfer member release protrusion  5121 , the bendable portion  5622  of the transfer member bends such that the angle between the latch arm  5618  and the latch extension  5617  is reduced, thus disengaging the transfer member  5600  from the medicament delivery mechanism  5300 . Said yet another way, when the transfer member  5600  is in its second configuration, the medicament delivery mechanism  5300  is isolated and/or no longer operably coupled to the spring  5420 . In this manner, as described below, the retraction force exerted by the biasing portion  5350  moves the medicament delivery mechanism  5300  proximally within the housing  5100  to retract the needle  5216 . 
       FIGS. 81 and 82  show the cover  5190  of the medical injector  5000 . The cover  5190  includes a proximal end portion  5191  and a distal end portion  5192 , and defines a cavity  5196 . The cavity  5196  of the cover  5190  is configured to receive at least a portion of the housing  5100 . Thus, when the portion of the housing  5100  is disposed within the cover  5190 , the cover  5190  blocks an optical pathway between the medicament container  5200  and a region outside of the housing  5100 . Similarly stated, when the portion of the housing  5100  is disposed within the cover  5190 , the cover  5190  is obstructs the first status indicator aperture  5130  and/or the second status indicator aperture  5160  of the housing  5100  to reduce the amount of light transmitted to the medicament  5220  within the medicament container  5200 . In this manner, the life of the medicament  5220  can be extended by the prevention and/or reduction of degradation to the medicament  5220  that may be caused by ultra-violet radiation. 
     The proximal end portion  5191  of the cover  5190  defines apertures  5193 . The apertures  5193  configured to receive the cover retention protrusions  5104  of the housing  5100  (shown in  FIGS. 10 and 12 ). In this manner, the apertures  5193  and the cover retention protrusions  5104  of the housing  5100  removably retain the cover  5190  about at least a portion of the housing  5100 . Said another way, the apertures  5193  and the cover retention protrusions  5104  of the housing  5100  are configured such that the cover  5190  can be removed from a portion of the housing  5100  and then replaced about the portion of the housing  5100 . 
     The cover  5190  can be any suitable configuration and can include any suitable feature. For example, the cover  5190  includes openings  5195  and notches  5194 . In some embodiments, the openings  5195  can receive inserts (not shown). The inserts can be flexible inserts and can be configured to increase friction between the cover  5190  and a surface. For example, the inserts can increase the friction between the cover  5190  and a surface on which the medical injector  5000  is placed, to prevent sliding. The notches  5194  are disposed at the proximal end of the cover  5190 . In some embodiments, the notches  5194  can be used to reduce the material needed to manufacture the cover  5190 . 
       FIGS. 83-87  show the safety lock  5700  of the medical injector  5000 . The safety lock  5700  of the medical injector  5000  includes a proximal surface  5730 , a distal surface  5740  opposite the proximal surface  5730  and a needle sheath  5810 . The safety lock  5700  defines a needle sheath aperture  5703 . The proximal surface  5730  of the safety lock  5700  includes two safety lock protrusions  5702 , two opposing pull-tabs  5710  and an engagement portion  5720 . As described above, when the safety lock  5700  is in a first (locked) position, the safety lock protrusions  5702  are configured to be disposed through the safety lock protrusion apertures  5514  defined by the base  5510  (see e.g.,  FIG. 88 ) and within the base lock openings  5131  defined by the distal end portion  5102  of the housing  5100  (see e.g.,  FIG. 73 ). Accordingly, the safety lock protrusions  5702  are configured to prevent the base locks  5515  of the base  5510  from moving past the base lock protrusion  5126  of the first housing member  5110 , thereby preventing proximal movement of the base  5510  and/or delivery of the medicament  5220 . Similarly stated, when the medical injector  5000  is in its first configuration (i.e., the storage configuration), the safety lock protrusions  5702  are disposed adjacent and/or in contact with the base lock protrusions  5126 , thereby preventing lateral deformation (e.g., a outward flexing motion) of the base lock protrusions  5126 . Thus, the arrangement of the safety lock protrusions  5702  prevents the system actuator  5500  and/or the base  5510  from moving in the proximal direction to actuate the medicament delivery mechanism  5300 . 
     The pull-tabs  5710  of the safety lock  5700  include a grip portion  5712 . The grip portion  5712  of the pull-tabs  5710  provides an area for the user to grip and/or remove the safety lock  5700  from the rest of the medicament delivery system  5700 . In some embodiments, the pull-tabs  5710  can include indicia, such as, for example, an indicia similar to that included in the pull tabs  3710  of the safety lock  3700 , described with reference to  FIG. 43 . 
     The engagement portion  5720  of the safety lock  5700  includes engagement members  5721 . The engagement members  5721  extend in a proximal direction from the proximal surface  5730 . The engagement members  5721  have tabs  5722  that extend from a surface of the engagement members  5721 . The tabs  5722  are configured to engage an outer surface  5815  of a distal end portion  5812  of the needle sheath  5810 . 
     As shown in  FIGS. 86 and 87 , the needle sheath  5810  includes the distal end portion  5812 , a proximal end portion  5811  and a rib  5816 . The needle sheath  5810  further includes a contoured portion  5814  that defines a bore  5813 . The bore  5813  of the needle sheath  5810  is configured to receive the needle  5216  and/or a distal end portion of the  5213  of the medicament container  5200 . The contoured portion  5814  of the needle sheath  5810  defines a friction fit with the distal end portion  5213  of the medicament container  5200 . In this manner, the needle sheath  5810  can protect the user from the needle  5216  and/or can keep the needle  5216  sterile before the user actuates the medical injector  5000 . The proximal end portion  5811  of the needle sheath is configured to contact the body  5210  of the medicament container  5200 . 
     The distal end portion  5812  of the needle sheath  5810  is configured to be inserted into a space defined between the tabs  5722  of the engagement members  5721  of the safety lock  5700 . The tabs  5722  are angled and/or bent towards the distal direction to allow the distal end portion  5812  of the needle sheath  5810  to move between the engagement members  5721  in a distal direction, but not in a proximal direction. Similarly stated, the tabs  5722  include an edge that contacts the outer surface  5815  of the needle sheath  5810  to prevent the safety lock  5700  from moving in a distal direction relative to the needle sheath  5810 . Said another way, the needle sheath  5810  is removed from the needle  5216  when the safety lock  5700  is moved in a distal direction with respect to the housing  5100  (see e.g.,  FIG. 90 ). 
       FIGS. 88 and 89  show the base  5510  (or actuator) of the medical injector  5000 . The base  5510  includes the proximal surface  5511 , a distal surface  5523  and base connection knobs  5518 . The base  5510  defines a needle aperture  5513 , safety lock protrusion apertures  5514 , transfer member access opening  5516  and pull-tab openings  5519 . The needle aperture  5513  is configured to receive the needle  5216  when the medical injector  5000  is actuated. The safety lock protrusion apertures  5514  of the base  5510  receive the safety lock protrusions  5702  of the safety lock  5700  when the medical injector  5000  is in the first configuration, as described above. The transfer member access opening  5516  provides access to the transfer member  5600  when the transfer member  5600  is disposed within the housing  5100 . The pull-tab openings  5519  are configured to receive the pull-tabs  5710  of the safety lock  5700  when the medical injector  5000  is in the first configuration. 
     The proximal surface  5511  of the base  5510  includes and/or is coupled to the release member  5530 , guide members  5517  and base locks  5515 . The release member  5530  includes a proximal end portion  5531  and a distal end portion  5532  and defines a channel  5533  between a system lock surface  5534  and the distal end portion  5532  (see e.g.,  FIG. 89 ). As shown in  FIG. 71 , the system lock surface  5534  is disposed at the proximal end portion  5531  and is configured to engage the first latch protrusion  5315  of the medicament delivery mechanism  5300 . Moreover, the system lock surface  5534  engages the first latch protrusion  5315  such that the system lock surface  5534  maintains the engagement of the first latch protrusion  5315  and the latch member notch  5120 , as described above and shown in  FIG. 72 . Similarly stated, the system lock surface  5534  of the release member  5530  applies a force to the first latch protrusion  5315  to maintain the first latch protrusion  5315  within the latch member notch  5120 . When the system actuator  5500  is moved in a proximal direction, as described in further detail herein, the system lock surface  5534  moves in the proximal direction to disengage the first latch protrusion  5315 . In response, the first latch protrusion  5315  moves within the channel  5533  of the release member  5530  in a distal direction, as described in further detail herein. Similarly stated, upon actuation of the medicament injector  5000 , a portion of the medicament delivery mechanism  5300  moves within the release member  5530 . 
     The guide members  5517  of the base  5510  are configured to engage and/or slide within the base rail grooves  5114  of the housing  5100 , as described above. The base locks  5515  of the base  5510  are configured to engage the base lock protrusions  5126  of the first housing member  5110 . As described in further detail herein, when the safety lock  5700  is removed and the base  5510  is moved in a proximal direction with respect to the housing  5100 , the base locks  5515  of the base  5510  are configured to disengage from the base lock protrusions  5126  and move in the proximal direction, relative to the base lock protrusions  5126 . As described above, the base connection knobs  5518  are configured to engage the base retention recesses  5134 A,  5134 B in a way that allows proximal movement of the base  5510  but limits distal movement of the base  5510 . 
     The medical injector  5000  is first enabled by moving the medicament delivery device  5000  from a first configuration to a second configuration by moving the cover  5190  from a first position to a second position. The cover  5190  is moved from the first position to the second position by moving it with respect to the housing  5100  in the distal direction. For example, the cover  5190  can be moved similarly to the cover  3190  of the medical injector  3000  described with reference to  FIG. 49 . 
     After the cover  5190  is removed from the housing  5100 , the medical injector  5000  can be moved from the second configuration to a third configuration by moving the safety lock  5700  from a first position to a second position. The safety lock  5700  is moved from a first position to a second position by moving the safety lock  5700  with respect to the housing  5100  in the direction shown by the arrow OO in  FIG. 90 . Similarly stated, the medical injector  5000  can be moved from the second configuration to a third configuration by removing the safety lock  5700  from the distal end portion  5102  of the housing  5100 . When the safety lock  5700  is moved from the first position to the second position, the safety lock protrusions  5702  are removed from within the base lock openings  5131  of the first housing member  5110 , thereby enabling the system actuator  5500  and/or the base  5510 . Similarly stated, when the safety lock  5700  is in the second position, the safety lock protrusions  5702  no longer maintain the engagement of the base locks  5515  with the base lock protrusions  5126  and/or the base locks  5515  can slide proximally relative to the base lock protrusion  5126  of the housing  5100 . In this manner, the base  5510  can be moved from a first position to a second position. Moreover, with the safety lock  5700  removed, the needle sheath  5810  is removed from the medicament container  5200 , as shown in  FIG. 91 . 
     After the safety lock  5700  is moved from the first position to the second position, the medical injector  5000  can be moved from the third configuration to a fourth configuration (i.e., the needle insertion configuration) by moving the base  5510  from the first position to the second position. Similarly stated, the medical injector  5000  can be actuated by the system actuator  5500  by moving the base  5510  proximally relative to the housing  5100 . The base  5510  is moved from its first position to its second position by placing the medical injector  5000  against the body of the patient and moving the base  5510  with respect to the housing  5100  in the direction shown by the arrow PP in  FIG. 92 . With the base locks  5515  disengaged from the base lock protrusions  5126 , the system actuator  5500  can move in the proximal direction causing the base locks  5515  move proximally past the base lock protrusions  5126 . 
     When the base  5510  is moved from the first position to the second position, the system actuator  5500  actuates the medicament delivery mechanism  5300 , thereby placing the medical injector  5000  in its fourth configuration (i.e., the needle insertion configuration), as shown in  FIGS. 92-94 . More specifically, the proximal movement of the system actuator  5500  and/or the base  5510  moves the release member  5530  in the proximal direction within the housing  5100 , thereby allowing the first latch protrusion  5315  to be disengaged from the system lock surface  5534  of the proximal end portion  5533  of the release member  5530 . Similarly stated, when the system actuator  5500  is moved in the proximal direction, the system lock surface  5534  disengages the first latch protrusion  5315 . Moreover, when the system lock surface  5534  moves in the proximal direction relative to the first latch protrusion  5315 , the first latch protrusion  5315  moves into the channel  5533  defined by the release member  5530 . 
     When the first latch protrusion  5315  is disposed within the channel  5533 , the force applied by the system lock surface  5534  of the base  5510  to maintain the first latch protrusion  5315  within the latch member notch  5120  is removed and the first latch protrusion  5315  is allowed to disengage the latch member notch  5120 . Therefore, the engagement surface  5109  of the latch member notch  5120  no longer applies the reaction force to the first latch protrusion  5315 ; thus, the spring  5420  is allowed to expand. As described above, the proximal end portion  5421  of the spring  5420  is in contact with the upper spring plate  5122  of the first housing member  5110  such that the spring  5420  expands in the direction shown be the arrow QQ in  FIG. 93 . With the distal end portion  5422  of the spring  5420  in contact with the spring seat  5615  of the transfer member  5600 , a force F4 produced by the expansion of the spring  5420  is applied to the transfer member  5600 , which moves the transfer member  5600  in the direction shown by the arrow QQ. In this manner, the latch  5620  of the transfer member  5600  transfers at least a portion of the force F4 to the second latch protrusion  5317  of the latch portion  5310  of the medicament delivery mechanism  5300  such that the portion of the force moves the medicament delivery mechanism  5300  in the distal direction, shown by the arrow QQ in  FIG. 93 . Thus, the medicament delivery mechanism  5300  (the first movable member) and the transfer member  5600  (the second movable member) move together distally within the housing. 
     When the medicament delivery mechanism  5300  is moving distally, the piston portion  5330  of the medicament delivery mechanism  5300  applies a portion of the force F4 to the medicament container  5200 . More specifically, as shown in  FIG. 94 , the first shoulder  5335  of each engagement member  5336  contacts the flange  5214  of the medicament container  5200 . The movement of the medicament delivery mechanism  5300  moves the piston portion  5330  in the distal direction. Therefore, with the first shoulder  5335  of each engagement member  5336  in contact with the flange  5214  of the medicament container  5200 , the first shoulder  5335  transfers a portion of the force F4 to the medicament container  5200  to move the medicament container  5200  in the distal direction. The movement of the medicament container  5200  within the housing  5100  results in the needle insertion operation. 
     As shown in  FIG. 78 , the distance between the end surface of the piston rod  5333  and the engagement members  5336  is such that when the first shoulder  5335  of each engagement member  5336  contacts the flange  5214 , the distal end portion  5332  of the piston rod  5333  is spaced apart from the elastomeric member  5217  within the medicament container  5200 . This arrangement prevents any portion of the force F4 from being applied or transferred to the plunger  5217 . Said another way, during the needle insertion operation (i.e., when the medical injector is being moved to its fourth configuration) the plunger  5217  is isolated from the piston portion  5330 . Accordingly, this arrangement reduces and/or eliminates leakage and/or injection of medicament  5220  from the medicament container  5200  during the needle insertion operation. 
     After the transfer member  5600 , the medicament delivery mechanism  5300  and the medicament container  5200  move in the distal direction a given distance, the damping member  5240  of the medicament container  5200  contacts the proximal surface  5108  of the medicament container holder  5127  and  5157  of the first housing portion  5110  and the second housing portion  5140 , respectively. The proximal surface  5108  prevents the medicament container  5200  from moving further in the distal direction. Thus, when the flange  5214  and/or the damping member  5240  contact the proximal surface  5108 , the needle  5216  is fully inserted into the target location of a patient. At this point, the medical injector  5000  can be moved from the fourth configuration to the fifth configuration (i.e., the medicament delivery configuration), shown in  FIGS. 95 and 96 . 
     When the damping member  5240  of the medicament container  5200  is in contact with the proximal surface  5108  of the medicament container holders  5127  and  5157 , the medicament container  5200  is prevented from moving in the distal direction. The portion of the force F4 applied by the spring  5420 , however, continues to urge the transfer member  5600  and the medicament delivery mechanism  5300  in the direction shown by the arrow RR in  FIG. 95 . More specifically, when the medicament container  5200  is in contact with the medicament container holders  5127  and  5157 , the force F4 applied by the spring  5420  moves the transfer member  5600  and the medicament delivery mechanism  5300  in the distal direction, relative to the medicament container  5200 . In this manner, the portion of the force F4 applied to the medicament delivery mechanism  5300  causes the deformable portion  5338  of the engagement members  5336  to deform and/or bend inward (see e.g.,  FIG. 96 ). Similarly stated, the deformable portion  5338  of each of the engagement members  5336  is configured to deform when the damping member  5240  of the medicament container  5200  is in contact with the proximal surface  5108  of the medicament container holders  5127  and  5157 . When the deformable portion  5338  is deformed, the engagement members  5336  are disposed within the recesses  5334  defined by the piston rod  5333  (see e.g.,  FIG. 96 ). In this manner, the piston rod  5333  is configured to move within the medicament container  5200  into contact with the elastomeric member  5217  to deliver the medicament  5220 . Similarly stated, the piston portion  5330  is moved from its first configuration, in which the engagement members  5336  collectively have a size that is greater than the size (i.e., diameter) of the inner bore of the medicament container  5200  to its second configuration, in which the engagement members  5336  collectively have a size that is less than the size (i.e., diameter) of the inner bore of the medicament container  5200 . This decrease in size (or diameter) allows the piston rod  5333  to move within the medicament container  5200 . 
     When the medicament delivery mechanism  5300  moves in the distal direction to move the elastomeric member  5217  and inject the medicament  5220 , the serpentine portion  5355  and/or the bias portion  5350  is also compressed. More specifically, a portion of the force F4 compresses the serpentine portion  5355  and/or the bias portion  5350  between the proximal end portion  5301  of the medicament delivery mechanism  5300  and the lower bias plate  5124 . Similarly stated, the bias portion  5350  is configured to compress as the serpentine portion  5355  elastically deforms (e.g., bending, squeezing, or compressing such that the bias portion  5350  returns to a non-deformed configuration when the deforming force is removed). In this manner, the space defined between adjacent portions of the serpentine portion  5355  is reduced. 
     As the spring  5420  fully expands, the medicament delivery mechanism  5300  moves in the distal direction to fully inject the medicament  5220  within the medicament container  5200  through the needle  5216 . Additionally, when the spring  5420  is fully expanded and/or when the medicament delivery mechanism  5300  has moved a desired distance within the housing  5100 , the latch arm  5618  of the transfer member  5600  engages the transfer member release protrusion  5121  of the housing  5100 . As described above, the transfer member release protrusion  5121  contacts the latch arm  5618  of the transfer member  5600  such that the bendable portion  5622  disposed at the distal end of the latch extension  5617  bends. In this manner, the latch  5620  of the latch arm  5618  is disengaged from the second latch protrusion  5318  of the latch portion  5310  of the medicament delivery mechanism  5300  (see e.g.,  FIGS. 97 and 98 ). Similarly stated, the spring  5240  and/or the transfer member  5600  are decoupled from the medicament delivery mechanism  5300 . With the latch arm  5618  disengaged from the latch portion  5310 , the medical injector  5000  can be moved from the fifth configuration to the sixth configuration (i.e., the retraction configuration). 
     As shown in  FIG. 98 , the transfer mechanism  5600  is deformed such that the transfer member  5600  and/or the spring  5420  are no longer engaged with the medicament delivery mechanism  5300 . Therefore, the medicament delivery mechanism  5300  is configured to move within the housing  5100  in the direction shown by the arrow SS in  FIG. 97  in response to the force produced by the bias portion  5350 . Similarly stated, with the medicament delivery mechanism  5300  disengaged from the transfer member  5600  and/or the spring  5420 , the force F4 is no longer applied to the medicament delivery mechanism  5300 . In this manner, the bias portion  5350  is configured to expand in the direction of the arrow SS shown in  FIG. 97  to apply a retraction force to the medicament delivery mechanism  5300 . Similarly stated, with the portion of the force F4 configured to compress the bias portion  5350  removed, the bias portion  5350  expands, returning to its uncompressed (i.e., non-deformed) configuration. 
     During the retraction operation, the second shoulder  5313  included in the latch portion  5310  is configured to engage a distal surface of the damping member  5240  and/or the flange  5214 . The second shoulder  5313  is further configured to transmit the retraction force produced by the expansion of the bias portion  5350  to the flange  5214 , thereby moving the medicament container  5200  proximally. Similarly stated, the medicament container  5200  is moved in the proximal direction towards the first position of the medicament container  5200 . This motion, removes the needle  5216  from the target location of the patient and retracts the needle into the housing  5100 , as shown in  FIG. 97 . 
     Any of the devices and/or medicament containers shown and described herein can include any suitable medicament or therapeutic agent. In some embodiments, the medicament contained within any of the medicament containers shown herein can be a vaccine, such as, for example, an influenza A vaccine, an influenza B vaccine, an influenza A (HINI) vaccine, a hepatitis A vaccine, a hepatitis B vaccine, a haemophilus influenza Type B (HiB) vaccine, a measles vaccine, a mumps vaccine, a rubella vaccine, a polio vaccine, a human papilloma virus (HPV) vaccine, a tetanus vaccine, a diphtheria vaccine, a pertussis vaccine, a bubonic plague vaccine, a yellow fever vaccine, a cholera vaccine, a malaria vaccine, a smallpox vaccine, a pneumococcal vaccine, a rotavirus vaccine, a varicella vaccine, a rabies vaccine and/or a meningococcus vaccine. In other embodiments, the medicament contained within any of the medicament containers shown herein can be a catecholamine, such as epinephrine. In yet other embodiments, the medicament contained within any of the medicament containers shown herein can include peptide hormones such as insulin and glucagon, human growth hormone (HGH), erythropoiesis-stimulating agents (ESA) such as darbepoetin alfa, monoclonal antibodies such as denosumab and adalimumab, interferons, etanercept, pegfilgrastim, and other chronic therapies, or the like. In yet other embodiments, the medicament contained within any of the medicament containers shown herein can be a placebo substance (i.e., a substance with no active ingredients), such as water. 
     In other embodiments, the medicament contained within any of the medicament containers shown herein can be an opioid receptor antagonist, such as naloxone, including any of the naloxone formulations described in U.S. patent application Ser. No. 13/036,720, entitled “Medicament Delivery Device for Administration of Opioid Antagonists Including Formulation for Naloxone,” filed on Feb. 28, 2011, incorporated by reference above. In one aspect, the present disclosure relates to compositions comprising naloxone or a pharmaceutically acceptable salt thereof suitable for use in the medicament delivery devices disclosed herein. Accordingly, the present naloxone compositions may be adapted for various administration routes, depending on the apparatus in which such composition(s) are to be employed. For example, in some embodiments, the present compositions may be adapted for transmucosal administration as, e.g., a nasal spray, or alternatively as a sublingual or buccal spray. In other embodiments, the present naloxone compositions may be adapted for parenteral administration as, e.g., an injectable solution. 
     The present compositions generally comprise an effective amount of naloxone, i.e., 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one, or a pharmaceutically acceptable salt and/or ester thereof. As used herein, an “effective amount” is an amount sufficient to provide a desired therapeutic effect. For example, as described herein, the present naloxone compositions may be useful in treating respiratory depression and/or other indications associated with opioid toxicity. Accordingly, an effective amount of naloxone in the present compositions may be an amount sufficient to treat such respiratory depression and/or other indications associated with opioid toxicity. The present naloxone compositions typically have a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one (or a salt and/or ester thereof) between about 0.01 mg/mL and about 10 mg/mL (e.g., between about 0.05 mg/mL and about 2 mg/mL, or any other value or range of values therein, including about 0.1 mg/mL, about 0.2 mg/mL, about 0.3 mg/mL, about 0.4 mg/mL, about 0.5 mg/mL, about 0.6 mg/mL, about 0.7 mg/mL, about 0.8 mg/mL, about 0.9 mg/mL, about 1.0 mg/mL, about 1.1 mg/mL, about 1.2 mg/mL, about 1.3 mg/mL, about 1.4 mg/mL, about 1.5 mg/mL, about 1.6 mg/mL, about 1.7 mg/mL, about 1.8 mg/mL, or about 1.9 mg/mL). 
     In some embodiments, the present naloxone compositions comprise a pH-adjusting agent. In some embodiments, the pH-adjusting agent includes at least one of hydrochloric acid, citric acid, acetic acid, phosphoric acid, or combinations thereof. The pH-adjusting agent may comprise an organic and/or inorganic acid or salt thereof (e.g., alkali metal salts [Li, Na, K, etc.], alkaline earth metal [e.g., Ca, Mg, etc.] salts, ammonium salts, etc.). In other embodiments, the pH-adjusting agent includes mixtures of one or more acids and one or more salts thereof, e.g., citric acid and citrate salts, acetic acid and acetate salts, phosphoric acid and phosphate salts, etc. In certain embodiments, the pH-adjusting agent is added in an amount sufficient to provide a pH of the present naloxone compositions of from about 3 to about 5 (for example a pH of about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, or about 5.0). Accordingly, the present compositions may comprise naloxone salts of the pH-adjusting agent employed. For example, in one embodiment, the pH-adjusting agent is dilute aqueous hydrochloric acid, and the naloxone salt is naloxone.HCl (e.g., 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)-morphinan-6-one hydrochloride). 
     Solvents suitable for use in the present compositions are not particularly limited, provided they are pharmaceutically acceptable. Accordingly, any pharmaceutically acceptable solvent in which the components of the present compositions are soluble, and which does not adversely affect the stability of the present compositions and/or the naloxone and/or naloxone salts contained therein may be employed. For example, in a typical composition, the solvent is sterile water (e.g., USP grade water for injection [WFI]). 
     In some embodiments, the present compositions may also comprise one or more tonicity-adjusting agents. For example, the tonicity-adjusting agent may include at least one of dextrose, glycerin, mannitol, potassium chloride, sodium chloride, or combinations thereof. The tonicity-adjusting agent(s) may be present in an amount of from about 0.1 mg/mL to about 50 mg/mL (e.g., including about 0.5 mg/mL, about 1.0 mg/mL, about 2.0 mg/mL, about 3.0 mg/mL, about 4.0 mg/mL, about 5.0 mg/mL, about 10 mg/mL, about 15 mg/mL, about 20 mg/mL, about 25 mg/mL, about 30 mg/mL, about 35 mg/mL, about 40 mg/mL, or about 45 mg/mL). In one embodiment, the tonicity-adjusting agent is sodium chloride, and the concentration thereof is between about 0.1 mg/mL and about 20 mg/mL. Generally, in naloxone compositions as described herein which are adapted for injection and/or intranasal delivery, tonicity-adjusting agents are added to provide a desired osmolality. In some embodiments, the osmolality of the naloxone compositions described herein is from about 250 to about 350 mOsm. 
     Because the naloxone compositions disclosed herein may be stored in the medicament container of the devices described herein for extended periods of time under varying storage conditions, in some embodiments the present compositions may further comprise stabilizers to prevent or inhibit decomposition of the naloxone during storage. Various types of pharmaceutically acceptable stabilizers can be used, including antioxidants (e.g. substituted phenols such as BHT, TBHQ, BHA, or propyl gallate; ascorbates such as ascorboyl palmitate, sodium ascorbate, ascorbic acid), complexing agents (e.g., cyclodextrins); or chelating agents such as EDTA (and its salts), D-gluconic acid δ-lactone, sodium or potassium gluconate, sodium triphosphate, and sodium hexametaphosphate. 
     Examples 
     The chemical stability of several exemplary naloxone hydrochloride compositions was evaluated at various pH and temperature conditions. The formulation of six development lots was performed to evaluate pH and order of addition parameters for naloxone hydrochloride. Assay testing was performed on aliquots of bulk formulation solution sampled prior to the filtration process to determine if the filtration process contributed to any API losses. 
     Exemplary naloxone compositions were prepared according to the formulations set forth in Table 1, below: 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Exemplary Naloxone Formulations. 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 Volume 
                   
               
               
                   
                   
                   
                   
                 API 
                   
                 NaCl 
                   
                   
                   
                 of  
                   
               
               
                   
                   
                 Order 
                   
                 Mix 
                   
                 Mix 
                   
                   
                   
                 pH 
                   
               
               
                   
                 Intial 
                 of 
                 API 
                 Time 
                 NaCl 
                 Time 
                   
                 Ad- 
                   
                 Ad- 
                 Final 
               
               
                   
                 WFI 
                 Addi- 
                 Added 
                 (sec- 
                 Added 
                 (sec- 
                 Intial 
                 justed 
                 Final 
                 juster 
                 Weight 
               
               
                 Lot 
                 (g) 
                 tion 
                 (mg) 
                 onds) 
                 (g) 
                 onds) 
                 pH 
                 pH 
                 pH 
                 (mL) 
                 (g) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 400.01 
                 A 
                 554.73 
                 110 
                 4.5000 
                 98 
                 5.52 
                 3.01 
                 2.99 
                 4.1 
                 500.00 
               
               
                 2 
                 400.15 
                 B 
                 555.10 
                 86 
                 4.5269 
                 69 
                 5.41 
                 6.51 
                 6.51 
                 0.5 
                 502.14 
               
               
                 3 
                 400.13 
                 A 
                 554.95 
                 104 
                 4.5033 
                 58 
                 5.39 
                 4.47 
                 4.47 
                 0.2 
                 502.17 
               
               
                 4 
                 400.00 
                 B 
                 554.58 
                 82 
                 4.4999 
                 87 
                 5.37 
                 3.01 
                 3.01 
                 4.0 
                 502.15 
               
               
                 5 
                 399.99 
                 A 
                 554.59 
                 85 
                 4.5513 
                 74 
                 5.40 
                 6.49 
                 6.49 
                 0.2 
                 502.16 
               
               
                 6 
                 400.02 
                 B 
                 554.81 
                 68 
                 4.5020  
                 70 
                 5.45 
                 4.50 
                 4.49 
                 0.2 
                 502.19 
               
               
                   
               
               
                 Final Formulation Solution Density = 1.0043 g/mL (Determined daring the formulation process for Lot 1) 
               
               
                 Order of Addition: 
               
               
                 A = Water, NACl, naloxone hydrochloride, pH adjuster 
               
               
                 B = Water, naloxone hydrochloride, NaCl, pH adjuster 
               
            
           
         
       
     
     There were no noticeable differences between the formulations from lot to lot. The order of addition of the components had no observable impact on the dissolution times for either the API (Naloxone Hydrochloride) or the NaCl. Initial solution pH values indicated no observable differences between the solutions prior to final pH adjustment. The volumes required for the final pH adjustment were also consistent, indicating no significant differences between the lots. 
     Solutions were filtered after formulation to determine if filtration after formulation impacts overall solution API concentration. Pre-filtration assay values were consistent with the post-filtration (initial) assay results for each lot, as shown in Table 2, below: 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Filtration of Naloxone Formulations. 
               
            
           
           
               
               
               
            
               
                   
                 Pre-Filtration Naloxone 
                 Post-Filtration Naloxone 
               
               
                 Lot 
                 Hydrochloride (mg/mL) 
                 Hydrochloride (mg/mL) 
               
               
                   
               
               
                 1 
                 1.02 
                 1.02 
               
               
                 2 
                 1.00 
                 1.00 
               
               
                 3 
                 1.01 
                 1.00 
               
               
                 4 
                 1.02 
                 1.01 
               
               
                 5 
                 1.00 
                 0.99 
               
               
                 6 
                 1.01 
                 0.99 
               
               
                   
               
            
           
         
       
     
     Because the naloxone compositions described herein may be stored in the medicament container of the devices described herein for extended periods of time under varying storage conditions, initial testing was performed to support a stability study for the development lots of naloxone hydrochloride. Initial appearance, pH and assay results are shown in Table 3, below: 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Initial Appearance, pH and Assay Results 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                 Osmo- 
                   
                   
               
               
                   
                 Rep- 
                   
                 lality 
                   
                 Assay 
               
               
                 Lot 
                 licate 
                 Appearance 
                 (mOsm) 
                 pH 
                 (mg/mL) 
               
               
                   
               
               
                 1 
                 1 
                 Clear, colorless solution free 
                 295 
                 3.09 
                 1.02 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 295 
                 3.09 
                 1.02 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 295 
                 3.09 
                 1.02 
               
            
           
           
               
               
               
               
               
               
            
               
                 2 
                 1 
                 Clear, colorless solution free 
                 294 
                 6.54 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 295 
                 6.55 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 295 
                 6.55 
                 1.00 
               
            
           
           
               
               
               
               
               
               
            
               
                 3 
                 1 
                 Clear, colorless solution free 
                 292 
                 4.92 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 289 
                 4.96 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 291 
                 4.94 
                 1.00 
               
            
           
           
               
               
               
               
               
               
            
               
                 4 
                 1 
                 Clear, colorless solution free 
                 294 
                 3.13 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 294 
                 3.14 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 294 
                 3.14 
                 1.01 
               
            
           
           
               
               
               
               
               
               
            
               
                 5 
                 1 
                 Clear, colorless solution free 
                 295 
                 6.57 
                 0.99 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 295 
                 6.57 
                 0.99 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 295 
                 6.57 
                 0.99 
               
            
           
           
               
               
               
               
               
               
            
               
                 6 
                 1 
                 Clear, colorless solution free 
                 292 
                 4.95 
                 0.99 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 290 
                 4.99 
                 0.99 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 291 
                 4.97 
                 0.99 
               
               
                   
                   
               
            
           
         
       
     
     The pH analysis of Lots 3 and 6 exhibited increases of 0.4 and 0.5, respectively, in comparison to the pH values obtained during the formulation process. To verify the initial bulk pH, an aliquot of bulk formulation solution for Lot 6 was removed from storage at 5° C. and allowed to equilibrate to room temperature. The determined pH was 4.52, confirming the final pH obtained during the formulation process. Analysis of related substances was performed for each individual sample, as shown in Table 4, below: 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Initial Related Substance Screening Results 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 2 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 0.559 
                 0.05 
                 0.05 
               
               
                 3 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 4 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 5 
                 1 
                 0.160 
                 0.11 
                 0.17 
                 0.09 
               
               
                   
                   
                 0.559 
                 0.06 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 6 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                   
               
               
                 NR = Not Reportable (&lt;0.05% Impurity) 
               
            
           
         
       
     
     In Table 4, % Related Substance=(Related Substance Peak Area/Total Integrated Area)×100. Peaks greater than or equal to 0.05% were reported. Replicates that exhibited levels of related substances that were not reportable were treated as 0.00% for determination of mean total related substances. 
     One month stability testing was conducted as previously described, with the following additional analyses: 
     pH analysis for all lots at the 25° C./60% RH condition 
     pH analysis for lots 1 and 4 at the 40° C./75% RH condition 
     Assay and Related Substances analysis for lots 1 and 4 at the 25° C./60% RH and 40° C./75% RH conditions 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 One-Month Stability Results - 70° C./75% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Assay 
               
               
                 Lot 
                 Replicate 
                 Appearance 
                 pH 
                 (mg/mL) 
               
               
                   
               
               
                 1 
                 1 
                 Clear, colorless solution free 
                 3.28 
                 1.02 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.25 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.27 
                 1.02 
               
            
           
           
               
               
               
               
               
            
               
                 2 
                 1 
                 Clear, colorless solution free 
                 6.05 
                 0.94 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 6.05 
                 0.94 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 6.05 
                 0.94 
               
            
           
           
               
               
               
               
               
            
               
                 3 
                 1 
                 Clear, colorless solution free 
                 5.32 
                 0.97 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 5.44 
                 0.97 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 5.38 
                 0.97 
               
            
           
           
               
               
               
               
               
            
               
                 4 
                 1 
                 Clear, colorless solution free 
                 3.28 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.28 
                 0.99 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.28 
                 1.00 
               
            
           
           
               
               
               
               
               
            
               
                 5 
                 1 
                 Clear, colorless solution free 
                 6.06 
                 0.94 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 6.05 
                 0.93 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 6.06 
                 0.93 
               
            
           
           
               
               
               
               
               
            
               
                 6 
                 1 
                 Clear, colorless solution free 
                 5.41 
                 0.95 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 5.27 
                 0.96 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 5.34 
                 0.95 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6a 
               
             
            
               
                   
               
               
                 One Month Related Substances Results - 
               
               
                 70° C./75% RH - Lots 1-3 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 0.038 
                 0.11 
                 0.42 
                 0.46 
               
               
                   
                   
                 0.404 
                 0.19 
               
               
                   
                   
                 0.597 
                 0.12 
               
               
                   
                 2 
                 0.038 
                 0.13 
                 0.50 
               
               
                   
                   
                 0.404 
                 0.23 
               
               
                   
                   
                 0.597 
                 0.14 
               
               
                 2 
                 1 
                 0.034 
                 0.08 
                 4.94 
                 4.77 
               
               
                   
                   
                 0.038 
                 0.21 
               
               
                   
                   
                 0.089 
                 0.08 
               
               
                   
                   
                 0.118 
                 0.08 
               
               
                   
                   
                 0.136 
                 4.23 
               
               
                   
                   
                 0.403 
                 0.11 
               
               
                   
                   
                 1.029 
                 0.15 
               
               
                   
                 2 
                 0.034 
                 0.07 
                 4.59 
               
               
                   
                   
                 0.038 
                 0.17 
               
               
                   
                   
                 0.089 
                 0.08 
               
               
                   
                   
                 0.136 
                 4.04 
               
               
                   
                   
                 0.403 
                 0.10 
               
               
                   
                   
                 1.028 
                 0.13 
               
               
                 3 
                 1 
                 0.038 
                 0.19 
                 2.79 
                 2.94 
               
               
                   
                   
                 0.118 
                 0.06 
               
               
                   
                   
                 0.136 
                 2.17 
               
               
                   
                   
                 0.403 
                 0.15 
               
               
                   
                   
                 0.596 
                 0.06 
               
               
                   
                   
                 1.026 
                 0.17 
               
               
                   
                 2 
                 0.038 
                 0.19 
                 3.09 
               
               
                   
                   
                 0.117 
                 0.05 
               
               
                   
                   
                 0.136 
                 2.46 
               
               
                   
                   
                 0.403 
                 0.15 
               
               
                   
                   
                 0.596 
                 0.05 
               
               
                   
                   
                 1.024 
                 0.19 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6b 
               
             
            
               
                   
               
               
                 One Month Related Substances Results - 
               
               
                 70° C./75% RH - Lots 4-6 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 4 
                 1 
                 0.038 
                 0.11 
                 0.44 
                 0.79 
               
               
                   
                   
                 0.403 
                 0.20 
               
               
                   
                   
                 0.596 
                 0.13 
               
               
                   
                 2 
                 0.039 
                 0.22 
                 1.13 
               
               
                   
                   
                 0.116 
                 0.09 
               
               
                   
                   
                 0.135 
                 0.09 
               
               
                   
                   
                 0.403 
                 0.46 
               
               
                   
                   
                 0.596 
                 0.28 
               
               
                 5 
                 1 
                 0.039 
                 0.18 
                 4.60 
                 4.80 
               
               
                   
                   
                 0.089 
                 0.07 
               
               
                   
                   
                 0.115 
                 0.05 
               
               
                   
                   
                 0.133 
                 4.20 
               
               
                   
                   
                 0.403 
                 0.10 
               
               
                   
                 2 
                 0.039 
                 0.18 
                 5.00 
               
               
                   
                   
                 0.089 
                 0.09 
               
               
                   
                   
                 0.132 
                 4.64 
               
               
                   
                   
                 0.402 
                 0.08 
               
               
                 6 
                 1 
                 0.038 
                 0.17 
                 2.85 
                 2.76 
               
               
                   
                   
                 0.132 
                 2.55 
               
               
                   
                   
                 0.403 
                 0.13 
               
               
                   
                 2 
                 0.038 
                 0.17 
                 2.66 
               
               
                   
                   
                 0.114 
                 0.06 
               
               
                   
                   
                 0.132 
                 2.31 
               
               
                   
                   
                 0.402 
                 0.13 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 One-Month Stability Results - 40° C./75% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Lot 
                 Replicate 
                 pH 
                 Assay (mg/mL) 
               
               
                   
                   
               
               
                   
                 1 
                 1 
                 3.14 
                 1.01 
               
               
                   
                   
                 2 
                 3.13 
                 1.01 
               
               
                   
                   
                 Mean (n = 2) 
                 3.14 
                 1.01 
               
               
                   
                 4 
                 1 
                 3.16 
                 1.01 
               
               
                   
                   
                 2 
                 3.16 
                 1.00 
               
               
                   
                   
                 Mean (n = 2) 
                 3.16 
                 1.00 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 One Month Related Substances Results - 40° C./75% RH 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 4 
                 1 
                 0.592 
                 0.05 
                 0.05 
                 0.22 
               
               
                   
                 2 
                 0.040 
                 0.12 
                 0.38 
               
               
                   
                   
                 0.115 
                 0.06 
               
               
                   
                   
                 0.592 
                 0.19 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 One-Month Stability Results - 25° C./60% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Lot 
                 Replicate 
                 pH 
                 Assay (mg/mL) 
               
               
                   
                   
               
               
                   
                 1 
                 1 
                 3.11 
                 1.01 
               
               
                   
                   
                 2 
                 3.16 
                 1.01 
               
               
                   
                   
                 Mean (n = 2) 
                 3.14 
                 1.01 
               
               
                   
                 2 
                 1 
                 6.33 
                 No analysis performed 
               
               
                   
                   
                 2 
                 6.41 
               
               
                   
                   
                 Mean (n = 2) 
                 6.37 
               
               
                   
                 3 
                 1 
                 5.20 
                 No analysis performed 
               
               
                   
                   
                 2 
                 5.21 
               
               
                   
                   
                 Mean (n = 2) 
                 5.21 
               
               
                   
                 4 
                 1 
                 3.19 
                 1.01 
               
               
                   
                   
                 2 
                 3.17 
                 1.01 
               
               
                   
                   
                 Mean (n = 2) 
                 3.18 
                 1.01 
               
               
                   
                 5 
                 1 
                 6.32 
                 No analysis performed 
               
               
                   
                   
                 2 
                 6.40 
               
               
                   
                   
                 Mean (n = 2) 
                 6.36 
               
               
                   
                 6 
                 1 
                 5.23 
                 No analysis performed 
               
               
                   
                   
                 2 
                 5.24 
               
               
                   
                   
                 Mean (n = 2) 
                 5.24 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 One Month Related Substances Results - 25° C./60% RH 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substances 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                 4 
                 1 
                 NR 
                 NR 
                 NR 
                 NR 
               
               
                   
                 2 
                 NR 
                 NR 
                 NR 
               
               
                   
               
            
           
         
       
     
     Three month stability testing was conducted as previously described, including the following measurements: 
     pH analysis for all lots at the 25° C./60% RH condition 
     pH analysis for lots 1 and 4 at the 40° C./75% RH condition 
     Assay and Related Substances analysis for lots 1 and 4 at the 25° C./60% RH and 40° C./75% RH conditions 
     
       
         
           
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 Three-Month Stability Results - 70° C./75% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Assay 
               
               
                 Lot 
                 Replicate 
                 Appearance 
                 pH 
                 (mg/mL) 
               
               
                   
               
               
                 1 
                 1 
                 Clear, colorless solution free 
                 3.70 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.70 
                 1.00 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.70 
                 1.00 
               
            
           
           
               
               
               
               
               
            
               
                 4 
                 1 
                 Clear, colorless solution free 
                 3.74 
                 0.96 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.77 
                 0.94 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.76 
                 0.95 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12a 
               
             
            
               
                   
               
               
                 Three Month Related Substances Results - 70° C./75% RH - Lot 1 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 0.039 
                 0.36 
                 1.70 
                 1.74 
               
               
                   
                   
                 0.096 
                 0.14 
               
               
                   
                   
                 0.136 
                 0.05 
               
               
                   
                   
                 0.165 
                 0.34 
               
               
                   
                   
                 0.364 
                 0.50 
               
               
                   
                   
                 0.384 
                 0.06 
               
               
                   
                   
                 0.555 
                 0.19 
               
               
                   
                   
                 1.112 
                 0.06 
               
               
                   
                 2 
                 0.039 
                 0.39 
                 1.79 
               
               
                   
                   
                 0.096 
                 0.15 
               
               
                   
                   
                 0.136 
                 0.05 
               
               
                   
                   
                 0.165 
                 0.41 
               
               
                   
                   
                 0.364 
                 0.47 
               
               
                   
                   
                 0.384 
                 0.06 
               
               
                   
                   
                 0.555 
                 0.18 
               
               
                   
                   
                 1.112 
                 0.07 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12b 
               
             
            
               
                   
               
               
                 Three Month Related Substances Results - 70° C./75% RH - Lot 4 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 4 
                 1 
                 0.039 
                 0.78 
                 3.44 
                 4.34 
               
               
                   
                   
                 0.095 
                 0.38 
               
               
                   
                   
                 0.112 
                 0.06 
               
               
                   
                   
                 0.135 
                 0.13 
               
               
                   
                   
                 0.155 
                 0.06 
               
               
                   
                   
                 0.164 
                 0.66 
               
               
                   
                   
                 0.312 
                 0.07 
               
               
                   
                   
                 0.363 
                 0.76 
               
               
                   
                   
                 0.383 
                 0.10 
               
               
                   
                   
                 0.554 
                 0.29 
               
               
                   
                   
                 1.111 
                 0.14 
               
               
                   
                 2 
                 0.039 
                 1.16 
                 5.23 
               
               
                   
                   
                 0.096 
                 0.58 
               
               
                   
                   
                 0.112 
                 0.11 
               
               
                   
                   
                 0.135 
                 0.21 
               
               
                   
                   
                 0.155 
                 0.07 
               
               
                   
                   
                 0.164 
                 0.96 
               
               
                   
                   
                 0.312 
                 0.11 
               
               
                   
                   
                 0.363 
                 1.19 
               
               
                   
                   
                 0.383 
                 0.14 
               
               
                   
                   
                 0.553 
                 0.46 
               
               
                   
                   
                 1.110 
                 0.24 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 Three-Month Stability Results - 40° C./75% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Assay 
               
               
                 Lot 
                 Replicate 
                 Appearance 
                 pH 
                 (mg/mL) 
               
               
                   
               
               
                 1 
                 1 
                 Clear, colorless solution free 
                 3.21 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.23 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.22 
                 1.01 
               
            
           
           
               
               
               
               
               
            
               
                 4 
                 1 
                 Clear, colorless solution free 
                 3.31 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.33 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.32 
                 1.01 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 Three Month Related Substances Results - 40° C./75% RH 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Unknown 
                   
                   
                 Mean of Total 
               
               
                   
                 Rep- 
                 (Identified 
                 % Related 
                 Total Related 
                 Related 
               
               
                 Lot 
                 licate 
                 by RRT) 
                 Substance 
                 Substances (%) 
                 Substances (%) 
               
               
                   
               
               
                 1 
                 1 
                 0.039 
                 0.06 
                 0.23 
                 0.17 
               
               
                   
                   
                 0.364 
                 0.06 
               
               
                   
                   
                 0.555 
                 0.11 
               
               
                   
                 2 
                 0.555 
                 0.10 
                 0.10 
               
               
                 4 
                 1 
                 0.039 
                 0.08 
                 0.25 
                 0.20 
               
               
                   
                   
                 0.363 
                 0.06 
               
               
                   
                   
                 0.554 
                 0.11 
               
               
                   
                 2 
                 0.039 
                 0.05 
                 0.14 
               
               
                   
                   
                 0.554 
                 0.09 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
             
            
               
                   
               
               
                 Three-Month Stability Results - 25° C./60% RH 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Assay 
               
               
                 Lot 
                 Replicate 
                 Appearance 
                 pH 
                 (mg/mL) 
               
               
                   
               
               
                 1 
                 1 
                 Clear, colorless solution free 
                 3.18 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.18 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.18 
                 1.01 
               
            
           
           
               
               
               
               
               
            
               
                 4 
                 1 
                 Clear, colorless solution free 
                 3.21 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
               
                   
                 2 
                 Clear, colorless solution free 
                 3.19 
                 1.01 
               
               
                   
                   
                 of visible particulate matter 
               
            
           
           
               
               
               
               
            
               
                   
                 Mean (n = 2) 
                 3.20 
                 1.01 
               
               
                   
                   
               
            
           
         
       
     
                     TABLE 16                  Three Month Related Substances Results - 25° C./60% RH                                             Unknown           Mean of Total           Rep-   (Identified   % Related   Total Related   Related       Lot   licate   by RRT)   Substance   Substances (%)   Substances (%)               1   1   NR   NR   NR   NR           2   NR   NR   NR       4   1   NR   NR   NR   NR           2   NR   NR   NR                    
Medicament Delivery Devices
 
     The naloxone compositions described herein can be included in any suitable medicament delivery device. For example, in some embodiments, a medicament delivery device configured for self-administration (or administration by an untrained user, such a person accompanying the patient) can include any of the naloxone compositions described herein. Such medicament delivery devices can include, for example, an auto-injector, an intranasal delivery device, a pre-filled syringe, an inhaler or the like. In this manner, the medicament delivery device (including the naloxone composition) can be used by the patient (or an untrained user) in any setting (e.g., the patient&#39;s home, in a public venue or the like). 
     In some embodiments, a medicament delivery device can be configured to automatically deliver any of the naloxone compositions described herein. Similarly stated, in some embodiments, a medicament delivery device, after being actuated by the user, can automatically produce (i.e., produce without any further human intervention) a force to deliver the naloxone composition. In this manner, the force with which the naloxone composition is delivered is within a desired range, and is repeatable between different devices, users or the like. 
     One example of such a medicament delivery device is provided in  FIG. 99 , which is a schematic illustration of a medicament delivery device  6000  according to an embodiment. The medicament delivery device  6000  includes a housing  6100 , a medicament container  6200  and an energy storage member  6400 . The medicament container  6200  is disposed within the housing  6100 , and contains (i.e., is filled or partially filled with) a naloxone composition  6220 . The energy storage member  6400  is disposed within the housing  6100 , and is configured to produce a force F5 to deliver the naloxone composition  6220  (e.g., from the medicament container  6200  to a body). 
     The naloxone composition  6220  can be any of the naloxone compositions described herein. In particular, the naloxone composition  6220  can include an effective amount of naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent. The naloxone composition  6220  can be formulated such that the osmolality of the naloxone composition  6220  ranges from about 250-350 mOsm and the pH ranges from about 3-5. 
     In some embodiments, the naloxone composition  6220  can include any suitable concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one. In some embodiments, for example, the naloxone composition  6220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.01 mg/mL and approximately 10 mg/mL. In other embodiments, the naloxone composition  6220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.05 mg/mL and approximately 2 mg/mL. 
     The tonicity-adjusting agent can be any of the tonicity-adjusting agents described herein, and can be included within the naloxone composition  6220  in any suitable amount and/or concentration. For example, in some embodiments, the tonicity-adjusting agent includes at least one of dextrose, glycerin, mannitol, potassium chloride or sodium chloride. In other embodiments, the tonicity-adjusting agent includes sodium chloride in an amount such that a concentration of sodium chloride is between approximately 0.1 mg/mL and approximately 20 mg/mL. 
     The pH-adjusting agent can be any of the pH-adjusting agents described herein, and can be included within the naloxone composition  6220  in any suitable amount and/or concentration. For example, in some embodiments, the pH-adjusting agent includes at least one of hydrochloric acid, citric acid, citrate salts, acetic acid, acetate salts, phosphoric acid or phosphate salts. In other embodiments, the pH-adjusting agent includes a dilute hydrochloric acid. 
     The medicament container  6200  can be any container suitable for storing the naloxone composition  6220 . In some embodiments, the medicament container  6200  can be, for example, a pre-filled syringe, a pre-filled cartridge, a vial, an ampule or the like. In other embodiments, the medicament container  6200  can be a container having a flexible wall, such as, for example, a bladder. 
     The energy storage member  6400  can be any suitable device or mechanism that, when actuated, produces a force F5 to deliver the naloxone composition  6220 . Similarly stated, the energy storage member  6400  can be any suitable device or mechanism that produces the force F5 such that the naloxone composition  6220  is conveyed from the medicament container  6200  into a body of a patient. The naloxone composition  6220  can be conveyed into a body via any suitable mechanism, such as, for example, by injection, intranasally, via inhalation or the like. By employing the energy storage member  6400  to produce the force F5, rather than relying on a user to manually produce the delivery force, the naloxone composition  6220  can be delivered into the body at the desired pressure and/or flow rate, and with the desired characteristics. Moreover, this arrangement reduces the likelihood of partial delivery (e.g., that may result if the user is interrupted or otherwise rendered unable to complete the delivery). 
     In some embodiments, the energy storage member  6400  can be a mechanical energy storage member, such as a spring, a device containing compressed gas, a device containing a vapor pressure-based propellant or the like. In other embodiments, the energy storage member  6400  can be an electrical energy storage member, such as a battery, a capacitor, a magnetic energy storage member or the like. In yet other embodiments, the energy storage member  6400  can be a chemical energy storage member, such as a container containing two substances that, when mixed, react to produce energy. 
     As shown in  FIG. 99 , the energy storage member  6400  can be in any position and/or orientation relative to the medicament container  6200 . In some embodiments, for example, the energy storage member  6400  can be positioned within the housing  6100  spaced apart from the medicament container  6200 . Moreover, in some embodiments, the energy storage member  6400  can be positioned such that a longitudinal axis of the energy storage member  6400  is offset from the medicament container  6200 . In other embodiments, the energy storage member  6400  can substantially surround the medicament container  6200 . 
     Moreover, the energy storage member  6400  can be operably coupled to the medicament container  6200  and/or the naloxone composition  6220  therein such that the force F5 delivers the naloxone composition  6220 . In some embodiments, for example, the force F5 can be transmitted to the naloxone composition  6220  via a piston or plunger (not shown in  FIG. 99 ). In other embodiments, the force F5 can be transmitted to the naloxone composition  6220  via a hydraulic or pneumatic coupling. In yet other embodiments, the force F5 can be transmitted to the naloxone composition  6220  electrically. In still other embodiments, the force F5 can be transmitted to the naloxone composition  6220  via a combination of any of the above. 
     In some embodiments, a medicament container can include an elastomeric member, such that the force produced by an energy storage member is transferred to the naloxone composition by the elastomeric member. For example,  FIG. 100  is a schematic illustration of a medicament delivery device  7000  according to an embodiment. The medicament delivery device  7000  includes a housing  7100 , a medicament container  7200 , an elastomeric member  7217  and an energy storage member  7400 . The medicament container  7200  is disposed within the housing  7100 , and contains (i.e., is filled or partially filled with) a naloxone composition  7220 . The naloxone composition  7220  can be any of the naloxone compositions described herein. The energy storage member  7400  is disposed within the housing  7100 , and is configured to produce a force F6 to deliver the naloxone composition  7220 , as described herein. 
     The elastomeric member  7217  is disposed within the medicament container  7200  to seal an end portion of the medicament container  7200 . The elastomeric member  7217  can be disposed within the medicament container  7200  during the fill process, and can form a substantially fluid-tight seal to prevent leakage of the naloxone composition  7220  from the medicament container  7200 . Moreover, the elastomeric member  7217  is operatively coupled to the energy storage member  7400  such that, in use the force F6 acts upon the elastomeric member  7217  to deliver the naloxone composition  7220  from the medicament container  7200 . 
     The elastomeric member  7217  is formulated to be compatible with the naloxone composition  7220 . Similarly stated, the elastomeric member  7217  is formulated to minimize any reduction in the efficacy of the naloxone composition  7220  that may result from contact (either direct or indirect) between the elastomeric member  7217  and the naloxone composition  7220 . For example, in some embodiments, the elastomeric member  7217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the naloxone composition  7220 . In other embodiments, the elastomeric member  7217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with naloxone over a long period of time (e.g., for up to six months, one year, two years, five years or longer). 
     In some embodiments, the elastomeric member  7217  can be formulated to include a polymer and a curing agent. In such embodiments, the polymer can include at least one of bromobutyl or chlorobutyl. In such embodiments, the curing agent can include at least one of sulfur, zinc or magnesium. 
     In some embodiments, the elastomeric member  7217  can be constructed from multiple different materials. For example, in some embodiments, at least a portion of the elastomeric member  7217  can be coated. Such coatings can include, for example, polydimethylsiloxane. In some embodiments, at least a portion of the elastomeric member  7217  can be coated with polydimethylsiloxane in an amount of between approximately 0.02 mg/cm 2  and approximately 0.80 mg/cm 2 . 
     A medicament delivery device configured for delivery of a naloxone composition can include an electronic circuit system that produces an output. Such output can include, for example, any output to assist the user and/or patient in administering the dose of the naloxone composition. For example,  FIG. 101  is a schematic illustration of a medicament delivery device  8000  according to an embodiment. The medicament delivery device  8000  includes a housing  8100 , a medicament container  8200 , an elastomeric member  8217 , an energy storage member  8400  and an electronic circuit system  8900 . The medicament container  8200  is disposed within the housing  8100 , and contains (i.e., is filled or partially filled with) a naloxone composition  8220 . The naloxone composition  8220  can be any of the naloxone compositions described herein. For example, in some embodiments, the naloxone composition  8220  can include an effective amount of naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent. The naloxone composition can be formulated such that the osmolality of the naloxone composition ranges from about 250-350 mOsm and the pH ranges from about 3-5. 
     The energy storage member  8400  is disposed within the housing  8100 , and is configured to produce a force F7 to deliver the naloxone composition  8220 , as described herein. The elastomeric member  8217  is disposed within the medicament container  8200  to seal an end portion of the medicament container  8200 . Moreover, the elastomeric member  8217  is operatively coupled to the energy storage member  8400  such that, in use the force F7 acts upon the elastomeric member  8217  to deliver the naloxone composition  8220  from the medicament container  8200 . 
     The electronic circuit system  8900  is configured to produce an output OP1 when the electronic circuit system  8900  is actuated. The output can be, for example, an audible or visual output related to the naloxone composition (e.g., an indication of the expiration date, the symptoms requirement treatment with naloxone or the like), the use of the medicament delivery device, and/or post-administration procedures (e.g., a prompt to call 911, instructions for the disposal of the device or the like). 
     For example, in some embodiments, the electronic output OP1 can be associated with an instruction for using the medicament delivery device  8000 . In other embodiments, the electronic output OP1 can be a post-use instruction, such as, for example, a recorded message notifying the user that the delivery of the naloxone composition  8220  is complete, instructing the user on post-use disposal of the medicament delivery device  8000  (e.g., post-use safety procedures), instructing the user to seek post-use medical treatment, and/or the like. In yet other embodiments, the electronic output OP1 can be associated with the patient&#39;s compliance in using medicament delivery device  8000 . 
     The electronic output OP1 can be, for example, a visual output such as, for example, a text message to display on a screen (not shown), and/or an LED. In some embodiments, the electronic output OP1 can be an audio output, such as, for example, recorded speech, a series of tones, and/or the like. In other embodiments, the electronic output OP1 can be a wireless signal configured to be received by a remote device. 
     As described in more detail herein, the electronic circuit system  8900  can include any suitable electronic components operatively coupled to produce and/or output the electronic output OP1 and/or to perform the functions described herein. The electronic circuit system  8900  can be similar to the electronic circuit systems described in U.S. Pat. No. 7,731,686, entitled “Devices, Systems and Methods for Medicament Delivery,” filed Jan. 9, 2007, which is incorporated herein by reference in its entirety. 
     The electronic circuit system  8900  can be actuated to produce the electronic output OP1 in any suitable manner. For example, in some embodiments, the electronic circuit system  8900  can be associated with an actuation of the medicament delivery device  8000 . Said another way, the electronic circuit system  8900  can be configured to output the electronic output OP1 in response to actuation of the medicament delivery device  8000 . In other embodiments, the electronic circuit system  8900  can be actuated manually by a switch (not shown in  FIG. 101 ). Such a switch can be actuated (i.e., to actuated the electronic circuit system  8900 ) by a push button, by removing the medicament delivery device  8000  from a case or cover (not shown in  FIG. 101 ), by receiving a signal from a remote electronic device, and/or any other suitable mechanism. In yet other embodiments, the electronic circuit system  8900  can be actuated by receiving input from the user via a voice prompt system. 
     The electronic circuit system  8900  can be coupled to and/or disposed within the housing  8100  in any suitable arrangement. For example, in some embodiments, the electronic circuit system  8900  can be coupled to an exterior or outer surface of the housing  8100 . In other embodiments, at least a portion of the electronic circuit system  8900  can be disposed within the housing  8100 . Moreover, in some embodiments, a portion of the electronic circuit system  8900  is disposed within the housing  8100  such that the portion of the electronic circuit system  8900  is fluidically and/or physically isolated from the medicament container  8200 . 
     The medicament delivery device  8000  can be any suitable device for automatically delivering any of the naloxone compositions described herein. In some embodiments, the medicament delivery device can be a medical injector configured to automatically deliver a naloxone composition. For example,  FIGS. 102-131  show a medical injector  9000 , according to an embodiment.  FIGS. 102-103  are perspective views of the medical injector  9000  in a first configuration (i.e., prior to use). The medical injector  9000  includes a housing  9100 , a delivery mechanism  9300  (see e.g.,  FIGS. 110-112 ), a medicament container  9200  containing a naloxone composition  9220  (see e.g.,  FIG. 113 ), an electronic circuit system  9900  (see e.g.,  FIGS. 115-118 ), a cover  9190  (see e.g.,  FIGS. 119 and 120 ), a safety lock  9700  (see e.g.,  FIGS. 121-123 ) and a system actuation assembly  9500  (see e.g.,  FIGS. 110, 112, 124 and 125 ). A discussion of the components of the medical injector  9000  will be followed by a discussion of the operation of the medical injector  9000 . 
     As shown in  FIGS. 104-109 , the housing  9100  has a proximal end portion  9101  and a distal end portion  9102 . The housing  9100  defines a first status indicator aperture  9130  and a second status indicator aperture  9160 . The first status indicator aperture  9130  defined by the housing  9100  is located on a first side of the housing  9100 , and the second status indicator aperture  9160  of the housing  9100  is located on a second side of the housing  9100 . The status indicator apertures  9130 ,  9160  can allow a patient to monitor the status and/or contents of the medicament container  9200  contained within the housing  9100 . For example, by visually inspecting the status indicator apertures  9130 ,  9160 , a patient can determine whether the medicament container  9200  contains a medicament and/or whether a medicament has been dispensed. 
     As shown in  FIGS. 107 and 108 , the housing  9100  defines a gas cavity  9151 , a medicament cavity  9139  and an electronic circuit system cavity  9137 . The gas cavity  9151  has a proximal end portion  9182  and a distal end portion  9153 . The gas cavity  9151  is configured to receive the gas container  9410  and a portion of the system actuation assembly  9500  (e.g., the release member  9550  and the spring  9576 , as shown in  FIGS. 110-112 ) as described in further detail herein. The proximal end portion  9182  of the gas cavity  9151  is configured to receive the gas container retention member  9580  of the proximal cap  9103  of the housing  9100 , as described in further detail herein. The gas cavity  9151  is in fluid communication with the medicament cavity  9139  via a gas passageway  9156  (see e.g.,  FIG. 109 ), as described in further detail herein, and the gas cavity  9151  is in fluid communication with a region outside the housing  9100  via a release member aperture  9154  (see e.g.,  FIGS. 107 and 108 ). 
     The medicament cavity  9139  is configured to receive the medicament container  9200  and a portion of the delivery mechanism  9300 . In particular, the carrier  9370  and the piston  9330  of the medicament delivery mechanism  9300  are movably disposed in the medicament cavity  9139 . The medicament cavity  9139  is in fluid communication with a region outside the housing  9100  via a needle aperture  9105  (see e.g.,  FIGS. 107 and 108 ). 
     The electronic circuit system cavity  9137  is configured to receive the electronic circuit system  9900 . The housing  9100  has protrusions  9136  (see e.g.,  FIG. 106 ) configured to stabilize the electronic circuit system  9900  when the electronic circuit system  9900  is disposed within the electronic circuit system cavity  9137 . The housing  9100  also defines connection apertures  9182  configured to receive connection protrusions  9174 A of the electronic circuit system  9900 , and aperture  9129  (see e.g.,  FIGS. 107 and 108 ) configured to receive a portion of a protrusion  9177  of the electronic circuit system  9900  (see e.g.,  FIG. 118 ). In this manner, the electronic circuit system  9900  can be coupled to the housing  9100  within the electronic circuit system cavity  9137 . In other embodiments, the electronic circuit system  9900  can be coupled within the electronic circuit system cavity  9137  by other suitable means such as an adhesive, a clip, a label and/or the like. 
     The electronic circuit system cavity  9137  is fluidically and/or physically isolated from the gas cavity  9151  and/or the medicament cavity  9139  by a sidewall  9150 . The sidewall  9150  can be any suitable structure to isolate the electronic circuit system cavity  9137  within the housing  9100  from the gas cavity  9151  and/or the medicament cavity  9139  within the housing  9100 . Similarly, the gas cavity  9151  and the medicament cavity  9139  are separated by a sidewall  9155 . In some embodiments, sidewall  9155  can be similar to the sidewall  9150 , which isolates the gas cavity  9151  and the medicament cavity  9139  from the electronic circuit system cavity  9137 . In other embodiments, the gas cavity  9151  can be fluidically and/or physically isolated from the medicament cavity  9139 . 
     The proximal end portion  9101  of the housing  9100  includes a proximal cap  9103 , a speaker protrusion  9138  (see e.g.,  FIGS. 106 and 107 ), and cover retention protrusions  9104  (see e.g.,  FIGS. 103 and 105 ). The speaker protrusion  9138  is configured to maintain a position of an audio output device  9956  of the electronic circuit system  9900  relative to the housing  9100  when the electronic circuit system  9900  is attached to the housing  9100 , as described herein. The cover retention protrusions  9104  are configured to be received within corresponding openings  9193  on the cover  9190 . In this manner, as described in more detail herein, the cover  9190  can be removably coupled to and disposed about at least a portion of the housing  9100 . 
     As shown in  FIG. 109 , the proximal cap  9103  includes a gas container retention member  9580  and defines a gas passageway  9156 . The gas container retention member  9580  is configured to receive and/or retain a gas container  9410  that can contain a pressurized gas. The gas passageway  9156  is configured to allow for the passage of gas contained in the gas container  9410  from the gas cavity  9151  to the medicament cavity  9139 , as further described herein. Said another way, the gas passageway  9156  places the gas cavity  9151  in fluid communication with the medicament cavity  9139 . 
     As shown in  FIGS. 105-107 , the distal end portion  9102  of the housing  9100  defines a battery isolation protrusion aperture  9135 , a needle aperture  9105 , a safety lock actuator groove  9133 , a release member aperture  9154 , a base actuator groove  9132 , base retention recesses  9134 A,  9134 B, and base rail grooves  9114 . The battery isolation protrusion aperture  9135  is configured to receive the battery isolation protrusion  9197  of the cover  9190  (see e.g.,  FIG. 120 ), as described in further detail herein. 
     The needle aperture  9105  is configured to allow the needle  9216  (see e.g.,  FIGS. 110, 128 and 129 ) to exit the housing  9100  when the medical injector  9000  is actuated. The portion of the sidewall of the housing  9100  that defines the needle aperture  9105  includes multiple sheath retention protrusions  9183 . In some embodiments, the sheath retention protrusions can interact with the plurality of ribs  9825  of the needle sheath  9810  (see e.g.  FIG. 123 ) to maintain a position of the needle sheath  9810  relative to the safety lock  9700  when the safety lock  9700  is coupled to the housing  9100  and/or when the safety lock  9700  is being removed from the housing  9100 . 
     The safety lock actuator groove  9133  is configured to receive an actuator  9724  of the safety lock  9700 . As described in more detail herein, the actuator  9724  is configured to engage and/or activate the electronic circuit system  9900  when the safety lock  9700  is moved with respect to the housing  9100 . The release member aperture  9154  is configured to receive a safety lock protrusion  9702  (see e.g.,  FIG. 121 ). As described in more detail below, when the medical injector is in the first configuration (i.e., when the safety lock  9700  is in place prior to use), the safety lock protrusion  9702  is disposed within an opening  9556  between extensions  9553  of a release member  9550  (see e.g.,  FIGS. 111 and 112 ) such that activation of the medical injector  9000  is prevented. The safety lock  9700 , its components and functions are further described herein. 
     The distal base retention recesses  9134 A are configured to receive the base connection knobs  9518  of the actuator  9510  (also referred to herein as “base  9510 ,” see e.g.,  FIG. 124 ) when the base  9510  is in a first position relative to the housing  9100 . The proximal base retention recesses  9134 B are configured to receive the base connection knobs  9518  of the base  9510  when the base  9510  is in a second position relative to the housing  9100 . The base retention recesses  9134 A,  9134 B have a tapered proximal sidewall and a non-tapered distal sidewall. This allows the base retention recesses  9134 A,  9134 B to receive the base connection knobs  9518  such that the base  9510  can move proximally relative to the housing  9100 , but cannot move distally relative to the housing  9100 . Said another way, the distal base retention recesses  9134 A are configured to prevent the base  9510  from moving distally when the base  9510  is in a first position and the proximal base retention recesses  9134 B are configured to prevent the base  9510  from moving distally when the base  9510  is in a second position. Similarly stated, the proximal base retention recesses  9134 B and the base connection knobs  9518  cooperatively prevent “kickback” after the medical injector  9000  is actuated. 
     The base actuator groove  9132  is configured to receive an actuator  9520  of the base  9510 . As described in more detail herein, the actuator  9520  of the base  9510  is configured to engage the electronic circuit system  9900  when the base  9510  is moved with respect to the housing  9100 . The base rail grooves  9114  are configured to receive the guide members  9517  of the base  9510 . The guide members  9517  of the base  9510  and the base rail grooves  9114  of the housing  9100  engage each other in a way that allows the guide members  9517  of the base  9510  to slide in a proximal and/or distal direction within the base rail grooves  9114  while limiting lateral movement of the guide members  9517 . This arrangement allows the base  9510  to move in a proximal and/or distal direction with respect to the housing  9100  but prevents the base  9510  from moving in a lateral direction with respect to the housing  9100 . 
       FIGS. 110-111  show the medicament container  9200 , the system actuation assembly  9500  and the medicament delivery mechanism  9300  of the medical injector  9000 . The medical injector  9000  is similar to the auto-injectors described in U.S. Pat. No. 7,648,482, entitled “Devices. Systems and Methods for Medicament Delivery,” filed Nov. 21, 2006, which is incorporated herein by reference in its entirety. 
     The medicament container  9200  of the medicament delivery mechanism  9300  has a distal end portion  9213  and a proximal end portion  9212 , and contains (i.e., is filled with or partially filled with) a naloxone composition  9220  (see, e.g.,  FIG. 113 ). The distal end portion  9213  of the medicament container  9200  contains a seal  9250 . The seal  9250 , which can be, for example, an 8-I crimp seal, is configured to burst when punctured by the proximal end  9253  of the needle  9216 , as described below. The proximal end portion  9212  of the medicament container  9200  includes an elastomeric member  9217 , and is configured to receive a piston rod  9333  of the piston  9330 . Although the medicament container  9200  is shown in  FIG. 113  as including a liner  9251 , in other embodiments, the medicament container  9200  need not include the liner  9251 . 
     The medicament container  9200  can have any suitable size (e.g., length and/or diameter) and can contain any suitable volume of the naloxone composition  9220 . Moreover, the medicament container  9200  and the piston  9330  can be collectively configured such that the piston  9330  travels a desired distance within the medicament container  9200  (i.e., the “stroke”) during an injection event. In this manner, the medicament container  9200 , the volume of the naloxone composition  9220  within the medicament container  9200  and the piston  9330  can be collectively configured to provide a desired fill volume and delivery volume. In some embodiments, for example, the size of the medicament container  9200  and the length of the piston  9330  can be such that the fill volume of the naloxone composition  9220  is approximately 0.76 ml and the delivery volume of the naloxone composition  9220  is approximately 0.30 ml (providing a delivery volume to fill volume ratio of approximately 0.4). In other embodiments, for example, the size of the medicament container  9200  and the length of the piston  9330  can be such that the fill volume of the naloxone composition  9220  is approximately 0.66 ml and the delivery volume of the naloxone composition  9220  is approximately 0.40 ml (providing a delivery volume to fill volume ratio of approximately 0.6). 
     Moreover, the length of the medicament container  9200  and the length of the piston  9330  can be configured such that the medicament delivery mechanism  9300  can fit in the same housing  9100  regardless of the fill volume, the delivery volume and/or the ratio of the fill volume to the delivery volume. In this manner, the same housing and production tooling can be used to produce devices having various dosages of the naloxone composition. For example, in a first embodiment (e.g., having a fill volume to delivery volume ratio of 0.4), the medicament container has a first length and the movable member has a first length. In a second embodiment (e.g., having a fill volume to delivery volume ratio of 0.6), the medicament container has a second length shorter than the first length, and the movable member has a second length longer than the first length. In this manner, the stroke of the device of the second embodiment is longer than that of the device of the first embodiment, thereby allowing a greater dosage. The medicament container of the device of the second embodiment, however, is shorter than the medicament container of the device of the first embodiment, thereby allowing the components of both embodiments to be disposed within the same housing and/or a housing having the same length. 
     The naloxone composition  9220  contained within the medicament container  9200  can be any of the naloxone compositions described herein. In particular, the naloxone composition  9220  can include an effective amount of naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent. The naloxone composition  9220  can be formulated such that the osmolality of the naloxone composition  9220  ranges from about 250-350 mOsm and the pH ranges from about 3-5. 
     In some embodiments, the naloxone composition  9220  can include any suitable concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one. In some embodiments, for example, the naloxone composition  9220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.01 mg/mL and approximately 10 mg/mL. In other embodiments, the naloxone composition  9220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.05 mg/mL and approximately 2 mg/mL. 
     The tonicity-adjusting agent can be any of the tonicity-adjusting agents described herein, and can be included within the naloxone composition  9220  in any suitable amount and/or concentration. For example, in some embodiments, the tonicity-adjusting agent includes at least one of dextrose, glycerin, mannitol, potassium chloride or sodium chloride. In other embodiments, the tonicity-adjusting agent includes sodium chloride in an amount such that a concentration of sodium chloride is between approximately 0.1 mg/mL and approximately 20 mg/mL. 
     The pH-adjusting agent can be any of the pH-adjusting agents described herein, and can be included within the naloxone composition  9220  in any suitable amount and/or concentration. For example, in some embodiments, the pH-adjusting agent includes at least one of hydrochloric acid, citric acid, citrate salts, acetic acid, acetate salts, phosphoric acid or phosphate salts. In other embodiments, the pH-adjusting agent includes a dilute hydrochloric acid. 
     The elastomeric member  9217  can be of any design or formulation suitable for contact with the naloxone composition  9220 . For example, the elastomeric member  9217  can be formulated to minimize any reduction in the efficacy of the naloxone composition  9220  that may result from contact (either direct or indirect) between the elastomeric member  9217  and the naloxone composition  9220 . For example, in some embodiments, the elastomeric member  9217  can be formulated to minimize any leaching or out-gassing of compositions that may have an undesired effect on the naloxone composition  9220 . In other embodiments, the elastomeric member  9217  can be formulated to maintain its chemical stability, flexibility and/or sealing properties when in contact (either direct or indirect) with naloxone over a long period of time (e.g., for up to six months, one year, two years, five years or longer). 
     In some embodiments, the elastomeric member  9217  can be formulated to include a polymer and a curing agent. In such embodiments, the polymer can include at least one of bromobutyl or chlorobutyl. In such embodiments, the curing agent can include at least one of sulfur, zinc or magnesium. 
     In some embodiments, the elastomeric member  9217  can be constructed from multiple different materials. For example, in some embodiments, at least a portion of the elastomeric member  9217  can be coated. Such coatings can include, for example, polydimethylsiloxane. In some embodiments, at least a portion of the elastomeric member  9217  can be coated with polydimethylsiloxane in an amount of between approximately 0.02 mg/cm 2  and approximately 0.80 mg/cm 2 . 
     As shown in  FIG. 110 , the system actuator  9500  includes the base  9510 , a release member  9550  and a spring  9576 .  FIG. 111  shows certain of the internal components of the medical injector  9000  without the base  9510  and the spring  9576  so that the release member  9550  can be more clearly shown. 
     The release member  9550  has a proximal end portion  9551  and a distal end portion  9552 , and is movably disposed within the distal end portion  9153  of the gas cavity  9151 . The proximal end portion  9551  of the release member  9550  includes a sealing member  9574  and a puncturer  9575 . The sealing member  9574  is configured to engage the sidewall of the housing  9100  defining the gas cavity  9151  such that the proximal end portion  9152  of the gas cavity  9151  is fluidically isolated from the distal end portion  9153  of the gas cavity  9151 . In this manner, when gas is released from the gas container  9410 , the gas contained in the proximal end portion  9152  of the gas cavity  9151  is unable to enter the distal end portion  9153  of the gas cavity  9151 . The puncturer  9575  of the proximal end portion  9551  of the release member  9550  is configured to contact and puncture a frangible seal  9411  on the gas container  9410  when the release member  9550  moves proximally within the gas cavity  9151 , as shown by the arrow TT in  FIG. 111 . 
     The distal end portion  9552  of the release member  9550  includes extensions  9553 . The extensions  9553  include projections  9555  that include tapered surfaces  9557  and engagement surfaces  9554 . Further, the extensions  9553  define an opening  9556  between the extensions  9553 . The engagement surfaces  9554  of the projections  9555  are configured to extend through the release member aperture  9154  of the housing  9100  and contact a distal surface of the housing  9100 , as shown in  FIG. 112 . In this manner, the engagement surfaces  9554  of the projections  9555  limit proximal movement of the release member  9550  when the engagement surfaces  9554  are in contact with the distal surface of the housing  9100 . 
     The opening  9556  defined by the extensions  9553  is configured to receive the safety lock protrusion  9702  of the safety lock  9700  (see e.g.,  FIGS. 112 and 121 ). The safety lock protrusion  9702  is configured to prevent the extensions  9553  from moving closer to each other. Said another way, the safety lock protrusion  9702  is configured to ensure that the extensions  9553  remain apart and the engagement surfaces  9554  of the projections  9555  remain in contact with the distal end portion  9102  of the housing  9100 . In some embodiments, for example, the release member  9550  and/or the extensions  9553  can be constructed from any suitable material configured to withstand deformation that may occur when exposed to a load over an extended period of time. In some embodiments, for example, the release member  9550  and/or the extensions  9553  can be constructed from brass. 
     The tapered surfaces  9557  of the projections  9555  are configured to contact protrusions  9515  on a proximal surface  9511  of the base  9510  (see e.g.,  FIG. 124 ) when the base  9510  is moved proximally relative to the housing  9100 . Accordingly, when the base  9510  is moved proximally relative to the housing  9100 , the extensions  9553  are moved together by the contact protrusions  9515 . The inward movement of the extensions  9553  causes the release member  9550  to become disengaged from the distal end portion of the housing  9100 , thereby allowing the release member  9550  to be moved proximally along its longitudinal axis as the spring  9576  expands. 
     The medicament delivery mechanism  9300  includes a gas container  9410 , a carrier  9370 , a piston  9330 , and a retraction spring  9351 . As described above, the carrier  9370  and the piston  9330  are disposed within the medicament cavity  9139  of the housing  9100 . The gas container  9410  is disposed within the gas cavity  9151  of the housing  9100 . 
     The gas container  9410  includes a distal end portion  9413  and a proximal end portion  9412 , and is configured to contain a pressurized gas. The distal end portion  9413  of the gas container  9410  contains a frangible seal  9411  configured to break when the puncturer  9575  of the proximal end portion  9551  of the release member  9550  contacts the frangible seal  9411 . The gas container retention member  9580  of the proximal cap  9103  of the housing  9100  is configured to receive and/or retain the proximal end portion  9412  of the gas container  9410 . Said another way, the position of the gas container  9410  within the gas cavity  9151  is maintained by the gas container retention member  9580 . 
     The piston  9330  of the medicament delivery mechanism  9300  is movably disposed within the medicament cavity  9139 . The piston  9330  includes a piston rod  9333  having a plunger at the distal end portion of the piston rod  9333 . The piston rod  9333  is configured to move within the medicament container  9200 . In this manner, the piston rod  9333  of the piston  9330  can apply a force to the elastomeric member  9217  to convey the naloxone composition  9220  contained in the medicament container  9200 . The piston rod  9333  can be constructed of a resilient, durable, and/or sealing material, such as a rubber. 
     The carrier  9370  of the medicament delivery mechanism  9300  includes a distal end portion  9372  and a proximal end portion  9371 . The medicament container  9200  is coupled to the carrier  9370  via a “snap-fit” connection (not shown) such that the medicament container  9200  can move relative to the carrier  9370  between a first configuration and a second configuration during an injection event. In the first configuration, the carrier  9370  is configured to move within the medicament cavity  9139  such that movement of the carrier  9370  within the medicament cavity  9139  causes contemporaneous movement of the medicament container  9200  within the medicament cavity  9139 . The proximal end portion  9253  of the needle  9216  is spaced apart from the seal  9250  of the medicament container  9200  when the carrier  9370  and the medicament container  9200  are collectively in the first configuration (e.g., during needle insertion). When the carrier  9370  and the medicament container  9200  are moved to the second configuration, the medicament container  9200  releases from the “snap-fit” causing the medicament container  9200  to move distally with respect to the carrier  9370 , causing the proximal end portion  9253  of the needle  9216  to pierce the seal  9250 . In this manner, the needle  9216  can be selectively placed in fluid communication with the medicament container  9200  to define a medicament delivery path (not shown). 
     As shown in  FIGS. 110, 111 and 130 , the proximal end portion  9371  of the carrier  9370  includes a gas valve actuator  9380 . The gas valve actuator  9380  is configured to engage a gas relief valve (not shown) of the piston  9330  to allow the pressurized gas contained within the gas chamber (i.e., the volume within the medicament cavity  9139  between the proximal end of the housing  9100  and the proximal end of the piston  9330 ) to escape when the injection event is complete. Thus, after the gas pressure within the medicament cavity  9139  decreases below a certain level, the force exerted by the retraction spring  9351  on the carrier  9370  can be sufficient to cause the carrier  9370  to move proximally within the housing  9100  (i.e., to retract). In addition, this arrangement results in there being substantially no residual force within the housing, which decreases stress on the components after the injection event. 
       FIGS. 115-118  show the electronic circuit system  9900 . The electronic circuit system  9900  of the medical injector  9000  includes an electronic circuit system housing  9170 , a printed circuit board  9922 , a battery assembly  9962 , an audio output device  9956 , two light emitting diodes (LEDs)  9958 A,  9958 B and a battery clip  9910 . The electronic circuit system  9900  is configured to fit within the electronic circuit system cavity  9137  of the housing  9100 . Accordingly, as described above, the electronic circuit system  9900  is physically and/or fluidically isolated from the medicament cavity  9139 , the gas cavity  9151  and/or the medicament delivery device  9300 . As described herein, the electronic circuit system  9900  is configured to output an electronic output associated with the use of the medical injector  9000 . Portions of the electronic circuit system  9900  are substantially similar to or the same as corresponding portions of the electronic circuit system  3900  included in the delivery device  3000  of  FIGS. 9-59 . Thus, similar portions are not described in further detail herein. 
     The electronic circuit system housing  9170  of the electronic circuit system  9900  includes a distal end portion  9172  and a proximal end portion  9171 . The proximal end portion  9171  includes connection protrusions  9174 A and a battery clip protrusion  9176 . The connection protrusions  9174 A extend from the proximal end portion  9171  of the electronic circuit system housing  9170 , and are configured to be disposed within the connection apertures  9182  of the housing  9100 , as described above. In this manner, the electronic circuit system  9900  can be coupled to the housing  9100  within the electronic circuit system cavity  9137 . In other embodiments, the electronic circuit system  9900  can be coupled to the housing  9100  by other suitable means such as an adhesive, a clip, a label and/or the like. As described in more detail herein, the battery clip protrusion  9176  is configured to hold the battery clip  9910  in place. 
     As shown in  FIGS. 115-118 , the distal end portion  9172  of the electronic circuit system housing  9170  includes a connection protrusion  9174 B, a stiffening protrusion  9177 , and defines an LED aperture  9178 , an aperture  9175 , a safety lock actuator groove  9179 , and a base actuator groove  9180 . The LED aperture  9178  is configured to receive the LEDs  9958 A,  9958 B such that a user can view the LEDs  9958 A,  9958 B, which are described in more detail herein. 
     The connection protrusion  9174 B extends from the distal end portion  9172  of the electronic circuit system housing  9170 , and is configured to attach the electronic circuit system  9900  to the housing  9100 , as described above. The stiffening protrusion  9177  is configured to have at least a portion received within and/or accessible via the aperture  9129  in the housing  9100  (see e.g.,  FIG. 105 ). The stiffening protrusion  9177  is configured to limit the bending (e.g., buckling) of the electronic circuit system housing  9170  when the electronic circuit system housing  9170  is coupled to the housing  9100 . Moreover, a user can access the stiffening protrusion  9177  via the aperture  9175 . In this manner, for example, the user can disengage the stiffening protrusion  9177  from the aperture  9129 . 
     The safety lock actuator groove  9179  of the electronic circuit system housing  9170  is configured to be disposed adjacent the safety lock actuator groove  9133  of the distal end portion  9102  of the housing  9100 . In this manner, the safety lock actuator groove  9179  of the electronic circuit system housing  9170  and the safety lock actuator groove  9133  of the distal end portion  9102  of the housing  9100  collectively receive the actuator  9724  of the safety lock  9700 , which is described in more detail herein. Similarly, the base actuator groove  9180  of the electronic circuit system housing  9170  is configured to be disposed about the base actuator groove  9132  of the distal end portion  9102  of the housing  9100 . The base actuator groove  9180  of the electronic circuit system housing  9170  and the base actuator groove  9132  of the distal end portion  9102  of the housing  9100  collectively receive the actuator  9520  of the base  9510 , which is described in more detail herein. 
     The printed circuit board  9922  of the electronic circuit system  9900  includes a substrate  9924 , a first actuation portion  9926  and a second actuation portion  9946 . The substrate  9924  of the printed circuit board  9922  includes the electrical components necessary for the electronic circuit system  9900  to operate as desired. For example, the electrical components can be resistors, capacitors, inductors, switches, microcontrollers, microprocessors and/or the like. The printed circuit board may also be constructed of materials other than a flexible substrate such as a FR4 standard board (rigid circuit board). The printed circuit board  9922  (including the first actuation portion  9926  and the second actuation portion  9946 ), the battery assembly  9962 , and the audio output device  9956  are substantially similar in form and function as the printed circuit board  3922 , the battery assembly  3962 , and the audio output device  3956 , respectively, included in the electronic circuit system  3900  of  FIGS. 29-39 . Therefore, the printed circuit board  992  and the battery assembly  9962  are not described in further detail herein. 
     The battery clip  9910  (shown in  FIG. 115 ) includes a proximal end portion  9912  and a distal end portion  9914 . The proximal end portion  9912  defines a retention aperture  9913 . The retention aperture  9913  is configured to receive the battery clip protrusion  9176  of the electronic circuit system housing  9170 . In this manner, the battery clip protrusion  9176  maintains the position of the battery clip  9910  with respect to the electronic circuit system housing  9170  and/or the battery assembly  9962 . 
     The distal end portion  9914  of the battery clip  9910  includes a contact portion  9916  and an angled portion  9915 . As described above, the contact portion  9916  is configured to contact the second surface  9966  of the battery assembly  9962  to place the battery assembly  9962  in electrical communication with the electronic circuit system  9900 . The angled portion  9915  of the distal end portion  9914  of the battery clip  9910  is configured to allow a proximal end portion  9198  of a battery isolation protrusion  9197  (see e.g.,  FIG. 120 ) to be disposed between the second surface  9966  of the battery assembly  9962  and the contact portion  9916  of the distal end portion  9914  of the battery clip  9910 . When the battery isolation protrusion  9197  is disposed between the second surface  9966  of the battery assembly  9962  and the contact portion  9916  of the distal end portion  9914  of the battery clip  9910 , the electrical path between the battery assembly  9962  and the remainder of the electronic circuit system  9900  is severed, thereby removing power from the electronic circuit system  9900 . The contact portion  9916  of the distal end portion  9914  of the battery clip  9910  is biased such that when the battery isolation protrusion  9197  is removed, the contact portion  9916  will move into contact the second surface  9966  of the battery assembly  9962 , thereby restoring electrical communication between the battery assembly  9962  and the electronic circuit system  9900 , as described above. 
       FIGS. 120 and 121  show the cover  9190  of the medical injector  9000 . The cover  9190  includes a proximal end portion  9191  and a distal end portion  9192 , and defines a cavity  9196 . The cavity  9196  of the cover  9190  is configured to receive at least a portion of the housing  9100 . Thus, when the portion of the housing  9100  is disposed within the cover  9190 , the cover  9190  blocks an optical pathway between the medicament container  9200  and a region outside of the housing  9100 . Similarly stated, when the portion of the housing  9100  is disposed within the cover  9190 , the cover  9190  is obstructs the first status indicator aperture  9130  and/or the second status indicator aperture  9160  of the housing  9100  to reduce the amount of light transmitted to the naloxone composition  9220  within the medicament container  9200 . In this manner, the life of the naloxone composition  9220  can extended by the prevention and/or reduction of degradation to the naloxone that may be caused by ultra-violet radiation. 
     The proximal end portion  9191  of the cover  9190  defines apertures  9193  configured to receive the cover retention protrusions  9104  of the housing  9100  (shown in  FIGS. 103 and 105 ). In this manner, the apertures  9193  and the cover retention protrusions  9104  of the housing  9100  removably retain the cover  9190  about at least a portion of the housing  9100 . Said another way, the apertures  9193  and the cover retention protrusions  9104  of the housing  9100  are configured such that the cover  9190  can be removed from a portion of the housing  9100  and then replaced about the portion of the housing  9100 . 
     As described above, the electronic circuit system  9900  can be actuated when the housing  9100  is at least partially removed from the cover  9190 . More particularly, the distal end portion  9192  of the cover  9190  includes a battery isolation protrusion  9197 . The battery isolation protrusion  9197  includes a proximal end portion  9198  and a tapered portion  9199 . The proximal end portion  9198  of the battery isolation protrusion  9197  is configured to be removably disposed between the second surface  9966  of the battery assembly  9962  and the contact portion  9916  of the distal end portion  9914  of the battery clip  9910 , as described above. 
       FIGS. 121-123  show the safety lock  9700  of the medical injector  9000 . The safety lock  9700  of the medical injector  9000  includes a proximal surface  9730 , a distal surface  9740  opposite the proximal surface  9730  and a needle sheath  9810 . The safety lock  9700  defines a needle sheath aperture  9703  and a battery isolation protrusion aperture  9728 . The battery isolation protrusion aperture  9728  is configured to receive the battery isolation protrusion  9197  of the cover  9190  such that the battery isolation protrusion  9197  can be disposed within the electronic circuit system cavity  9137  or the electronic circuit system  9900 , as described above. Similarly stated, the battery isolation protrusion aperture  9728  of the safety lock  9700  is aligned with the battery isolation protrusion aperture  9728  of the housing  9100 , such that the battery isolation protrusion  9197  can be disposed within the electronic circuit system cavity  9137  when the cover  9190  is disposed about a portion of the housing  9100 . 
     The proximal surface  9730  of the safety lock  9700  includes a safety lock protrusion  9702 , a stopper  9727 , an actuator  9724  and two opposing pull tabs  9710 . As described above, when the safety lock  9700  is in a first (locked) position, the safety lock protrusion  9702  is configured to be disposed in the opening  9556  defined by the extensions  9553  of the distal end portion  9552  of the release member  9550  (see also  FIG. 112 ). Accordingly, the safety lock protrusion  9702  is configured to prevent the extensions  9553  from moving closer to each other, thereby preventing proximal movement of the release member  9550  of the medicament delivery mechanism  9300  and/or delivery of the naloxone composition  9220 . The stopper  9727  of the safety lock  9700  is a protrusion extending from the proximal surface  9730  of the safety lock  9700 . The stopper  9727  is configured to contact a portion of the housing  9100  to limit the proximal movement of the safety lock  9700  relative to the housing  9100 . In other embodiments, the stopper  9727  can be any structure configured to limit the proximal movement of the safety lock  9700 . 
     The actuator  9724  of the safety lock  9700  has an elongated portion  9725  and a protrusion  9726 . The elongated portion  9725  extends in a proximal direction from the proximal surface  9730 . In this manner, the elongated portion  9725  can extend through a safety lock actuator opening  9524  of the base  9510  (see e.g.,  FIG. 35 ) and within the safety lock actuator groove  9133  of the housing  9100  and the safety lock actuator groove  9179  of the electronic circuit system housing  9170 . The protrusion  9726  extends in a direction substantially transverse to the elongated portion  9725  and/or substantially parallel to the proximal surface  9730  of the safety lock  9700 . As described above, the first actuation portion  9926  is configured to receive the protrusion  9726  of the actuator  9724  of the safety lock  9700 . 
     The pull tabs  9710  of the safety lock  9700  include a grip portion  9712  and indicia  9741 . The grip portion  9712  of the pull tabs  9710  provides an area for the user to grip and/or remove the safety lock  9700  from the rest of the medicament delivery system  9000 . The indicia  9741  provides instruction on how to remove the safety lock  9700 . In some embodiments, for example, the indicia  9741  can indicate the direction the user should pull the safety lock  9700  to remove the safety lock  9700 . 
     As shown in  FIGS. 122 and 123 , the needle sheath  9810  of the safety lock  9700  includes a distal end portion  9811 , a proximal end portion  9812  and a plurality of ribs  9825 . The needle sheath  9810  can also define a lumen  9813 . The lumen  9813  of the safety lock  9700  is configured to receive the needle  9216 . In this manner, the needle sheath  9810  can protect the user from the needle  9216  and/or can keep the needle  9216  sterile before the user actuates the medical injector  9000 . The proximal end portion  9812  of the needle sheath is configured to contact the distal end portion  9372  of the carrier  9370  of the medicament delivery mechanism  9300 . 
     The distal end portion  9811  of the needle sheath  9810  has an angled ridge  9827 . The angled ridge  9827  is configured to allow the proximal end portion  9812  of the needle sheath  9810  to irreversibly move through the needle sheath aperture  9703  of the safety lock  9700  in a distal direction. Said another way, the angled ridge  9827  can be configured in such a way as to allow the proximal end portion  9812  of the needle sheath  9810  to move through the needle sheath aperture  9703  in a distal direction, but not in a proximal direction. The needle sheath aperture  9703  has retaining tabs  9722  configured to engage the proximal end of the angled ridge  9827  when the needle sheath  9810  is moved in a proximal direction. In this manner, the retaining tabs  9722  prevent the proximal movement of the needle sheath with respect to the safety lock  9700 . Further, the retaining tabs  9722  are configured to engage the proximal end of the angled ridge  9827  when the safety lock  9700  is moved in a distal direction. Said another way, the needle sheath  9810  is removed from the needle  9216  when the safety lock  9700  is moved in a distal direction with respect to the housing  9100 . 
       FIGS. 124 and 125  show the base  9510  of the medical injector  9000 . The base  9510  includes a proximal surface  9511 , a distal surface  9523  and base connection knobs  9518 . The base  9510  defines a needle aperture  9513 , a safety lock protrusion aperture  9514 , a battery isolation protrusion aperture  9521 , a safety lock actuator opening  9524 , and pull tab openings  9519 . The needle aperture  9513  is configured to receive the needle  9216  when the medical injector  9000  is actuated. The safety lock protrusion aperture  9514  of the base  9510  receives the safety lock protrusion  9702  of the safety lock  9700 . The battery isolation protrusion aperture  9521  of the base  9510  receives the battery isolation protrusion  9197  of the cover  9190  and the stopper  9727  of the safety lock  9700 . The safety lock actuator opening  9524  receives the safety lock actuator  9724  of the safety lock  9700 . The pull tab openings  9519  are configured to receive the pull tabs  9710  of the safety lock  9700 . 
     The proximal surface  9511  of the base  9510  includes an actuator  9520 , guide members  9517 , and protrusions  9515 . The actuator  9520  is an elongate member configured to engage the substrate  9924  of the electronic circuit system  9900 . As described above, the opening  9945  of the second actuation portion  9946  is configured to receive the actuator  9520  of the base  9510 . The guide members  9517  of the base  9510  are configured to engage and/or slide within the base rail grooves  9114  of the housing  9100 , as described above. The protrusions  9515  of the base  9510  are configured to engage the tapered surfaces  9557  of the extensions  9553  of the release member  9550 . As described in further detail herein, when the safety lock  9700  is removed and the base  9510  is moved in a proximal direction with respect to the housing  9100 , the protrusion  9515  of the base  9510  are configured to move the extensions  9553  of the release member  9550  closer to each other, actuating the medicament delivery mechanism  9300 . As described above, the base connection knobs  9518  are configured to engage the base retention recesses  9134 A,  9134 B in a way that allows proximal movement of the base  9510  but limits distal movement of the base  9510 . 
     As shown in  FIG. 126 , the medical injector  9000  is first enabled by moving the medicament delivery device  9000  from a first configuration to a second configuration by moving the cover  9190  from a first position to a second position. The cover  9190  is moved from the first position to the second position by moving it with respect to the housing  9100  in the direction shown by the arrow UU in  FIG. 126 . When the cover  9190  is moved with respect to the housing  9100  in the direction UU, the battery isolation protrusion  9197  is removed from the area between the battery clip  9910  and the second surface  9966  of the battery assembly  9962 . In this manner, the battery assembly  9962  can be operatively coupled to the electronic circuit system  9900  when the cover  9190  is removed, thereby providing power to the electronic circuit system  9900 . Similarly stated, this arrangement allows the electronic circuit system  9900  to be actuated when the cover  9190  is removed. 
     When power is provided, as described above, the electronic circuit system  9900  can output one or more predetermined electronic outputs. For example, in some embodiments, the electronic circuit system  9900  can output an electronic signal associated with recorded speech to the audible output device  9956 . Such an electronic signal can be, for example, associated with a .WAV file that contains a recorded instruction instructing the user in the operation of the medical injector  9000 . Such an instruction can state, for example, “remove the safety tab near the base of the auto-injector.” The electronic circuit system  9900  can simultaneously output an electronic signal to one and/or both of the LEDs  9958 A,  9958 B thereby causing one and/or both of the LEDs  9958 A,  9958 B to flash a particular color. In this manner, the electronic circuit system  9900  can provide both audible and visual instructions to assist the user in the initial operation of the medical injector  9000 . 
     In other embodiments, the electronic circuit system  9900  can output an electronic output associated with a description and/or status of the medical injector  9000  and/or the naloxone composition  9220  contained therein. For example, in some embodiments, the electronic circuit system  9900  can output an audible message indicating the symptoms for which the naloxone composition should be administered, the expiration date of the naloxone composition, the dosage of the naloxone composition or the like. 
     After the cover  9190  is removed from the housing  9100 , the medical injector  9000  can be moved from the second configuration to a third configuration by moving the safety lock  9700  from a first position to a second position. The safety lock  9700  is moved from a first position to a second position by moving the safety lock  9700  with respect to the housing  9100  in the direction shown by the arrow VV in  FIG. 127 . When the safety lock  9700  is moved from the first position to the second position, the safety lock protrusion  9702  is removed from between the extensions  9553  of the release member  9550 , thereby enabling the medicament delivery mechanism  9300 . Moreover, as shown in  FIGS. 126 and 127 , when the safety lock  9700  is moved from the housing  9100 , the actuator  9724  of the safety lock  9700  actuates the first actuation portion  9926  of the electronic circuit system  9900 , as described above with reference to the delivery device  3000  of  FIGS. 9-59 . 
     After the safety lock  9700  is moved from the first position to the second position, the medical injector  9000  can be moved from the third configuration to a fourth configuration by moving the base  9510  from a first position to a second position. Similarly stated, the medical injector  9000  can be actuated by the system actuation assembly  9500  by moving the base  9510  distally relative to the housing  9100 . The base  9510  is moved from its first position to its second position by placing the medical injector  9000  against the body of the patient and moving the base  9510  with respect to the housing  9100  in the direction shown by the arrow WW in  FIG. 128 . Moving the base  9510  from the first position to the second position causes the protrusions  9515  on the proximal surface  9511  of the base  9510  to engage the tapered surfaces  9557  of the extensions  9553  of the release member  9550 , thereby moving the extensions  9515  together. The inward movement of the extensions  9553  causes the release member  9550  to become disengaged from the distal end portion of the housing  9100 , thereby allowing the release member  9550  to be moved proximally along its longitudinal axis as the spring  9576  expands. 
     When the base  9510  is moved from the first position to the second position, the system actuator  9500  actuates the medicament delivery mechanism  9300 , thereby placing the medical injector  9000  in its fourth configuration (i.e., the needle insertion configuration), as shown in  FIGS. 128 and 129 . More particularly, when the medical injector is in its fourth configuration, the puncturer  9575  of the release member  9550  is in contact with and/or disposed through the frangible seal  9411  of the gas container  9410 . 
     After the frangible seal  9411  has been punctured, an actuating portion of a compressed gas can escape from the gas container  9410  and flow via the gas passageway  9156  into the medicament cavity  9139 . The gas applies gas pressure to the piston  9330  causing the piston  9330  and the carrier  9370  to move in a distal direction within the medicament cavity  9139 , as shown by the arrow XX in  FIG. 129 . When the carrier  9370  moves distally within the medicament cavity  9139 , the carrier  9370  and the medicament container  9200  are in a first configuration. Accordingly, as described above, the medicament container  9200  is connected to the carrier  9370  by a “snap fit” connection. In this manner, the medicament container  9200  and the needle  9216  contemporaneously move with piston  9330  and/or the carrier  9370  in a distal direction. As described above, the proximal end portion  9253  of the needle  9216  is connected to the distal end portion  9372  of the carrier  9370  and is spaced from the seal  9250  of the medicament container  9200  when the carrier  9370  is in its first configuration. Said another way, the medicament container  9200  and the needle  9216  do not define a medicament delivery path when the carrier  9370  is in the first configuration. The movement of the needle  9216  in a distal direction causes the distal end portion of the needle  9216  to exit the housing  9100  and enter the body of a patient prior to administering the naloxone composition  9220 . 
     After the carrier  9370  and/or the needle  9216  have moved within the medicament cavity  9139  a predetermined distance, the carrier  9370  and the medicament container  9200  are moved from the first configuration to a second configuration. In the second configuration of the carrier  9370 , the medicament container  9200  is released from the “snap-fit” allowing the medicament container  9200  and the piston  9330  to continue to move in a distal direction relative to the carrier  9370 . Said another way, the medicament container  9200  is configured to slidably move within the carrier  9370  when the carrier is moved from the first configuration to the second configuration. As the medicament container  9200  continues to move within the carrier  9370 , the proximal end portion  9253  of the needle  9216  contacts and punctures the seal  9250  of the medicament container  9200 . This allows the medicament contained in the medicament container  9200  to flow into the lumen (not shown) defined by the needle  9216 , thereby defining a medicament delivery path. 
     After the medicament container  9200  contacts the distal end of the carrier  9370 , the medicament container  9200  stops moving within the carrier  9370  while the piston  9330  continues to move in a distal direction, as shown by the arrow YY in  FIG. 130 . This causes the piston  9330  to move within the medicament container  9200  containing the naloxone composition  9220 . As the piston rod  9333  of the piston  9330  moves within the medicament container  9200 , the piston rod  9333  contacts the elastomeric member  9217  and generates a pressure upon the naloxone composition  9220  contained within the medicament container  9200 , thereby allowing at least a portion of the naloxone composition  9220  to flow out of the medicament container  9200  and into the lumen defined by the needle  9216 . The medicament is delivered to a body of a user via the medicament delivery path defined by the medicament container  9200  and the needle  9216 . 
     As shown in  FIG. 131 , after the piston  9330  moves a predetermined distance within the medicament container  9200 , the gas valve actuator  9380  of the carrier  9370  engages the gas relief valve (not shown in  FIG. 131 ) of the piston  9330  thereby allowing the pressurized gas contained within the gas chamber (i.e., the volume within the medicament cavity  9139  between the proximal end of the housing  9100  and the proximal end of the piston  9330 ) to escape. Similarly stated, the gas valve actuator  9380  of the carrier  9370  engages the gas relief valve of the piston  9330 , the pressure within the housing  9100  is reduced, thereby ending the injection event. In this manner, the pre-injection distance between the proximal end portion of the piston  9330  and the gas valve actuator  9380  of the carrier  9370  can be adjusted to control the amount of the naloxone composition  9220  to be injected. After the gas pressure within the medicament cavity  9139  decreases below a certain level, the force exerted by the retraction spring  9351  on the carrier  9370  can be sufficient to cause the carrier  9370  to move proximally within the housing  9100  (i.e., to retract), as shown by the arrow ZZ in  FIG. 131 . 
     As described above with reference to the delivery device  3000  of  FIGS. 9-59 , the actuator  9520  of the base  9510  actuates the second actuation portion  9946  of electronic circuit  9900  to trigger a predetermined output or sequence of outputs when the base  9510  is moved from its first position to its second position (see, e.g.,  FIGS. 37 and 39 ). For example, in some embodiments, the electronic circuit system  9900  can output an electronic signal associated with recorded speech to the audible output device  9956 . Such an electronic signal can be, for example, associated with an audible countdown timer, instructing the user on the duration of the injection procedure, and/or the like (as described in detail above with reference to the delivery device  3000 ). 
     Although the electronic circuit system  9900  is shown and described above as having two irreversible switches (e.g., switch  9972  and switch  9973 ), in other embodiments, an electronic circuit system can have any number of switches. Moreover, such switches can be either reversible or irreversible. For example,  FIGS. 132-137  show portions of a medicament delivery device  10000  having an electronic circuit system  10900  having three irreversible switches. 
     The medicament delivery device  10000  is similar to the medical injector  9000  described above. As shown in  FIGS. 132 and 133  (which show only portions of the medicament delivery device  10000 ), the medicament delivery device  10000  includes a housing  10100 , a delivery mechanism (not shown), an electronic circuit system  10900 , a cover (not shown), a safety lock (not shown, similar to safety lock  9700 ) and a base (not shown, similar to base  9510 ). The structure and operation of the delivery mechanism, the cover, the safety lock and the base are similar to the structure and operation of the delivery mechanism  9300 , the cover  9190 , the safety lock  9700  and the base  9510 , respectively. Accordingly, only the electronic circuit system  10900  and the housing  10100  are described in detail below. 
     As shown in  FIG. 132 , the housing  10100  has a proximal end portion  10101  and a distal end portion  10102 . The housing  10100  defines a gas cavity (not shown), a medicament cavity (not shown) and an electronic circuit system cavity  10137 . The gas cavity and medicament cavity of the housing  10100  of the medicament delivery device  10000  are similar to the gas cavity  9151  and the medicament cavity  9139 , shown and described above with reference to  FIGS. 107 and 108 . 
     The electronic circuit system cavity  10137  is configured to receive the electronic circuit system  10900 . As described above, the electronic circuit system cavity  10137  is fluidically and/or physically isolated from the gas cavity and/or the medicament cavity by a sidewall  10150 . The housing  10100  has protrusions  10136  configured to stabilize the electronic circuit system  10900  when the electronic circuit system  10900  is disposed within the electronic circuit system cavity  10137 . The housing  10100  also defines connection apertures (not shown) configured to receive connection protrusions  10174 A of the electronic circuit system  10900  (see e.g.,  FIG. 133 ). In this manner, the electronic circuit system  10900  can be coupled to the housing  10100  within the electronic circuit system cavity  10137  (see e.g.,  FIG. 136 ). In other embodiments, the electronic circuit system  10900  can be coupled within the electronic circuit system cavity  10137  by any other suitable means, such as an adhesive, a clip and/or the like. 
     The housing  10100  includes an actuation protrusion  10165  disposed within the electronic circuit system cavity  10137 . As described in more detail herein, an angled end portion  10166  of the actuation protrusion  10165  of the housing  10100  is configured to engage a third actuation portion  10976  of a substrate  10924  of the electronic circuit system  10900  when the electronic circuit system  10900  is coupled to the housing  10100 . 
     As shown in  FIG. 136 , the electronic circuit system  10900  is configured to fit within the electronic circuit system cavity  10137  of the housing  10100 . Accordingly, as described above, the electronic circuit system  10900  is physically and/or fluidically isolated from the medicament cavity, the gas cavity and/or the medicament delivery path within the medicament delivery device  10000  (not shown). As described herein, the electronic circuit system  10900  is configured to output an electronic output associated with a use of the medicament delivery device  10000 . 
     As shown in  FIG. 133 , the electronic circuit system  10900  is similar to the electronic circuit system  9900  described above. The electronic circuit system  10900  of the medicament delivery device  10000  includes an electronic circuit system housing  10170 , a printed circuit board  10922 , a battery assembly  10962 , an audio output device  10956 , two light emitting diodes (LEDs)  10958 A,  10958 B and a battery clip  10910 . The electronic circuit system housing  10170 , the battery assembly  10962 , the audio output device  10956 , the two light emitting diodes (LEDs)  10958 A,  10958 B and the battery clip  10910  are similar to the electronic circuit system housing  9170 , the battery assembly  9962 , the audio output device  9956 , the two light emitting diodes (LEDs)  9958 A,  9958 B and the battery clip  9910  of the electronic circuit system  9900  described above. Thus, a detailed discussion of these components is omitted. 
     The electronic circuit system  10900  also includes a processor  10950  configured to process electronic inputs (e.g., from input switches) and produce electronic outputs. As described herein, such electronic outputs can include audio or visual outputs associated with a use of the medicament delivery device  10000 . The processor  10950  can be a commercially-available processing device dedicated to performing one or more specific tasks. For example, in some embodiments, the processor  10950  can be a commercially-available microprocessor, such as the Sonix SNC 17060 or the SNC 711120 voice synthesizers. Alternatively, the processor  10950  can be an application-specific integrated circuit (ASIC) or a combination of ASICs, which are designed to perform one or more specific functions. In yet other embodiments, the processor  10950  can be an analog or digital circuit, or a combination of multiple circuits. 
     The processor  10950  can include a memory device (not shown) configured to receive and store information, such as a series of instructions, processor-readable code, a digitized signal, or the like. The memory device can include one or more types of memory. For example, the memory device can include a read only memory (ROM) component and a random access memory (RAM) component. The memory device can also include other types of memory suitable for storing data in a form retrievable by the processor  10950 , for example, electronically-programmable read only memory (EPROM), erasable electronically-programmable read only memory (EEPROM), or flash memory. 
       FIG. 134  shows the printed circuit board  10922  of the electronic circuit system  10900 .  FIG. 135  is a schematic illustration of the electronic circuit system  10900 . The printed circuit board  10922  of the electronic circuit system  10900  includes a substrate  10924 , a first actuation portion  10926  (including a first switch  10972 ), a second actuation portion  10946  (including a second switch  10973 ), and a third actuation portion  10976  (including an electronic circuit system configuration switch  10974 ). The substrate  10924  of the printed circuit board  10922  includes the electrical components necessary for the electronic circuit system  10900  to operate as desired. For example, the electrical components can include resistors, capacitors, inductors, switches, microcontrollers, microprocessors and/or the like. 
     The first actuation portion  10926  and the second actuation portion  10946  are similar to the first actuation portion  9926  and the second actuation portion  9946  of the electronic circuit system  9900 , described above (see e.g.,  FIG. 133 ), and are therefore not described or labeled in detail. The third actuation portion  10976  includes a third electrical conductor  10936  (see e.g.,  FIG. 134 ) and defines an actuation aperture  10975  having a boundary  10979 , and a tear propagation limit aperture  10978 . As shown in  FIGS. 133 and 137 , the actuation aperture  10975  of the third actuation portion  10976  is configured to receive the angled end portion  10166  of the actuation protrusion  10165  of the housing  10100  when the electronic circuit system  10900  is disposed within the electronic circuit system cavity  10137 . The boundary  10979  of the actuation aperture  10975  has a discontinuous shape, such as, for example, a teardrop shape, that includes a stress concentration riser  10977 . The discontinuity and/or the stress concentration riser  10977  of the boundary  10979  can be of any suitable shape to cause the substrate  10924  to deform in a predetermined direction when the angled end portion  10166  of the actuation protrusion  10165  of the housing  10100  is inserted into the actuation aperture  10975  (see e.g.,  FIG. 137 ), as described below. 
     The third electrical conductor  10936  includes the electronic circuit system configuration switch  10974  (see e.g.,  FIG. 134 ) disposed between the actuation aperture  10975  and the tear propagation limit aperture  10978 , which can be, for example, a frangible portion of the third electrical conductor  10436 . As shown in  FIGS. 136 and 137 , when the electronic circuit system  10900  is attached to the housing  10100 , a portion of the angled portion  10166  of the actuation protrusion  10165  is disposed within the actuation aperture  10975  of the third actuation portion  10976 , as shown by the arrow AAA in  FIG. 137 . Continued movement of the angled portion  10166  of the actuation protrusion  10165  within the third actuation portion  10976  of the substrate  10924  causes the third actuation portion  10976  of the substrate  10924  to tear, thereby separating the portion of the third electrical conductor  10936  including the electronic circuit system configuration switch  10974 . Said another way, when the electronic circuit system  10900  is attached to the housing  10100 , the actuation protrusion  10165  moves irreversibly the electronic circuit system configuration switch  10974  from a first state (e.g., a state of electrical continuity) to a second state (e.g., a state of electrical discontinuity). 
     The tear propagation limit aperture  10978  is configured to limit the propagation of the tear in the substrate  10924 . Said another way, the tear propagation limit aperture  10978  is configured to ensure that the tear in the substrate  10924  does not extend beyond the tear propagation limit aperture  10978 . The tear propagation limit aperture  10978  can be any shape configured to limit the propagation of a tear and/or disruption of the substrate  10924 . For example, the tear propagation limit aperture  10978  can be oval shaped. In other embodiments, the boundary of the tear propagation limit aperture  10978  can be reinforced to ensure that the tear in the substrate  10924  does not extend beyond the tear propagation limit aperture  10978 . The angled end portion  10166  of the actuation protrusion  10165  ensures that the tear in the substrate  10924  propagates in the desired direction. Said another way, the angled end portion  10166  of the actuation protrusion  10165  ensures that the tear in the substrate  10924  occurs between the actuation aperture  10975  and the tear propagation limit aperture  10978 . 
     When the actuation protrusion  10165  of the housing  10100  moves irreversibly the electronic circuit system configuration switch  10974  of the electronic circuit system  10900  from the first state to the second state, the electronic circuit system  10900  can be moved between a first configuration and a second configuration. For example, in some embodiments, irreversibly moving the electronic circuit system configuration switch  10974  of the electronic circuit system  10900  to the second state places the electronic circuit system  10900  in the second configuration such that when power is applied to the electronic circuit system  10900 , the electronic circuit system  10900  recognizes that the medicament delivery device  9000  is a certain type of medicament delivery device and/or is in a certain configuration. In some embodiments, the housing can be devoid of the actuation protrusion  10165 , thus the electronic circuit system configuration switch  10974  is maintained in its first state when the electronic circuit system  10900  is attached to the housing  10100 . In this manner, the electronic circuit system configuration switch  10974  can enable the electronic circuit system  10900  to be used in different types and/or configurations of medicament delivery devices. The dual functionality of the electronic circuit system  10900  enables production of the same electronic circuit system  10900  for multiple devices, thereby permitting mass production and decreasing the cost of production of the electronic circuit system  10900 . 
     For example, in some embodiments the electronic circuit system  10900  can be used in either an actual medicament delivery device or a simulated medicament delivery device. A simulated medicament delivery device can, for example, correspond to an actual medicament delivery device and can be used, for example, to train a user in the operation of the corresponding actual medicament delivery device. 
     The simulated medicament delivery device can simulate the actual medicament delivery device in any number of ways. For example, in some embodiments, the simulated medicament delivery device can have a shape corresponding to a shape of the actual medicament delivery device, a size corresponding to a size of the actual medicament delivery device and/or a weight corresponding to a weight of the actual medicament delivery device. Moreover, in some embodiments, the simulated medicament delivery device can include components that correspond to the components of the actual medicament delivery device. In this manner, the simulated medicament delivery device can simulate the look, feel and sounds of the actual medicament delivery device. For example, in some embodiments, the simulated medicament delivery device can include external components (e.g., a housing, a needle guard, a sterile cover, a safety lock or the like) that correspond to external components of the actual medicament delivery device. In some embodiments, the simulated medicament delivery device can include internal components (e.g., an actuation mechanism, a compressed gas source, a medicament container or the like) that correspond to internal components of the actual medicament delivery device. 
     In some embodiments, however, the simulated medicament delivery device can be devoid of a medicament and/or those components that cause the medicament to be delivered (e.g., a needle, a nozzle or the like). In this manner, the simulated medicament delivery device can be used to train a user in the use of the actual medicament delivery device without exposing the user to a needle and/or a medicament. Moreover, the simulated medicament delivery device can have features to identify it as a training device to prevent a user from mistakenly believing that the simulated medicament delivery device can be used to deliver a medicament. For example, in some embodiments, the simulated medicament delivery device can be of a different color than a corresponding actual medicament delivery device. Similarly, in some embodiments, the simulated medicament delivery device can include a label clearly identifying it as a training device. 
     The actuation of the medicament delivery device configuration switch  10974  can configure the electronic circuit system  10900  to output a different electronic output when the medicament delivery device  10000  is a simulated medical injector than when the medicament delivery device  10000  is an actual medical injector. Said yet another way, the electronic circuit system  10900  can be configured to output a first series of electronic outputs when the electronic circuit system configuration switch  10974  is in the first state and a second series of electronic outputs when the electronic circuit system configuration switch  10974  is in the second state. In this manner, the electronic circuit system configuration switch  10974  can enable the same electronic circuit system  10900  to be used in both simulated medicament delivery devices and actual medicament delivery devices. When used on an actual medicament delivery device, for example, the housing can be devoid of the actuation protrusion  10165 . The dual functionality of the electronic circuit system  10900  can decrease the cost of production of the electronic circuit system  10900  of the medicament delivery device  9000 . 
     In other embodiments, moving the electronic circuit system configuration switch  10974  to the second state can place the electronic circuit system  10900  in any number of different functional configurations. For example, moving the electronic circuit system configuration switch  10974  from the first state to the second state can indicate the type of medicament in the medicament container, the dosage of the medicament and/or the language of the audible electronic outputs output by the electronic circuit system  10900 . 
     In still other embodiments, any number of electronic circuit system configuration switches can be used. For example, multiple switches can be used to configure the electronic circuit system  10900  to output usage instructions in any number of languages. For example, if an electronic circuit system contained three configuration switches (e.g., switches A, B and C), switch A can correspond to English instructions, switch B to Spanish instructions and switch C to German instructions. Further, moving both switch A and B to the second state might correspond to French instructions. In this manner, a single electronic circuit system  10900  can be configured to output instructions in multiple languages. 
     The needle  9216 , as well as any other needles shown and described herein, can have any diameter and/or length to facilitate the injection of the naloxone composition  9220 . For example, the needle can have a length suitable to penetrate clothing and deliver the naloxone via a subcutaneous injection and/or an intramuscular injection. In some embodiments, the needle  9216  (and any needle disclosed herein) can have a length of greater than 1 inch, greater than 1.5 inches, greater than 2 inches, greater than 2.5 inches or greater than 3 inches. In some embodiments, the needle  9216  (and any needle disclosed herein) can have a lumen diameter of approximately between 19-gauge and 31-gauge. 
     Although the medical injectors  9000  and  10000  are shown and described above as being auto-injectors configured to deliver the naloxone compositions described herein via injection through a needle (e.g., needle  9216 ), in other embodiments, a medicament delivery device can be configured to deliver the naloxone compositions described herein via any suitable delivery member, and in any suitable manner. For example, in some embodiments, a medicament delivery device can include a delivery member that delivers the naloxone composition into the body via inhalation and/or intranasal delivery. 
     For example,  FIG. 138  is a schematic illustration of a medicament delivery device  11000  according to an embodiment that is configured to deliver a naloxone composition intranasally and/or via inhalation. The medicament delivery device  11000  includes a housing  11100 , a medicament container  11200 , a delivery member  11300  and an energy storage member  11400 . The medicament container  11200  is at least partially disposed within the housing  11100 , and contains (i.e., is filled or partially filled with) a naloxone composition  11220 . The delivery member  11300  is coupled to the medicament container  11200 , and, as described herein, is configured to deliver the naloxone composition from the medicament container  11200  intranasally and/or via inhalation. The energy storage member  11400  is disposed within the housing  11100 , and is configured to produce a force F8 to deliver the naloxone composition  11220  (e.g., from the medicament container  11200  to a body). 
     The naloxone composition  11220  can be any of the naloxone compositions described herein. In particular, the naloxone composition  11220  can include an effective amount of naloxone or salts thereof, a tonicity-adjusting agent, and a pH-adjusting agent. The naloxone composition  11220  can be formulated such that the osmolality of the naloxone composition  11220  ranges from about 250-350 mOsm and the pH ranges from about 3-5. 
     In some embodiments, the naloxone composition  11220  can include any suitable concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl) morphinan-6-one. In some embodiments, for example, the naloxone composition  11220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.01 mg/mL and approximately 60 mg/mL. In other embodiments, the naloxone composition  11220  has a concentration of 4,5-epoxy-3,14-dihydroxy-17-(2-propenyl)morphinan-6-one between approximately 0.05 mg/mL and approximately 2 mg/mL. 
     The tonicity-adjusting agent can be any of the tonicity-adjusting agents described herein, and can be included within the naloxone composition  11220  in any suitable amount and/or concentration. For example, in some embodiments, the tonicity-adjusting agent includes at least one of dextrose, glycerin, mannitol, potassium chloride or sodium chloride. In other embodiments, the tonicity-adjusting agent includes sodium chloride in an amount such that a concentration of sodium chloride is between approximately 0.1 mg/mL and approximately 20 mg/mL. 
     The pH-adjusting agent can be any of the pH-adjusting agents described herein, and can be included within the naloxone composition  11220  in any suitable amount and/or concentration. For example, in some embodiments, the pH-adjusting agent includes at least one of hydrochloric acid, citric acid, citrate salts, acetic acid, acetate salts, phosphoric acid or phosphate salts. In other embodiments, the pH-adjusting agent includes a dilute hydrochloric acid. 
     The medicament container  11200  can be any container suitable for storing the naloxone composition  11220 . In some embodiments, the medicament container  11200  can be, for example, a pre-filled syringe, a pre-filled cartridge, a vial, an ampule or the like. In other embodiments, the medicament container  11200  can be a container having a flexible wall, such as, for example, a bladder. Although shown and described as being partially disposed within the housing  11100 , in other embodiments, the medicament container  11200  can be disposed entirely within the housing  11100 . Moreover, in some embodiments, the medicament container  11200  can be movably disposed within the housing  11100 , such as, for example, in a manner similar to the medicament container  9200  shown and described above. 
     The delivery member  11300  is coupled to the medicament container  11200  and defines, at least in part, a flow path through which the naloxone composition  11220  can be delivered into a body. Although shown as being directly coupled to a distal end portion of the medicament container  11200 , in other embodiments, the delivery member  11300  can be indirectly coupled to the medicament container  11200 , (e.g., via the housing  11100 ). 
     Moreover, in some embodiments, the delivery member  11300  can be coupled to, but fluidically isolated from, the medicament container  11200  prior to actuation of the energy storage member  11400 . In this manner, the medicament delivery device  11000  can be stored for extended periods of time while maintaining the sterility of the naloxone composition  11220  contained within the medicament container  11200 , reducing (or eliminating) any leakage of the naloxone composition  11220  from the medicament container  11200  or the like. This arrangement also reduces and/or eliminates the assembly operations (e.g., the operation of coupling the delivery member  11300  to the medicament container  11200 ) before the medicament delivery device  11000  can be used to administer the naloxone composition  11220 . In this manner, the medicament delivery device  11000  produces a quick and accurate mechanism for delivering the naloxone composition  11220 . Similarly stated by reducing and/or eliminating the assembly operations prior to use, this arrangement reduces likelihood that performance of medicament delivery device  11000  and/or the delivery member  11300  will be compromised (e.g., by an improper coupling, a leak or the like). 
     In some embodiments, the delivery member  11300  can be coupled to the medicament container  11200  via a coupling member (not shown in  FIG. 138 ) having similar functionality to the carrier  9370  shown and described above with respect to the medicament delivery device  9000 . In such an embodiment, the medicament container  11200  and/or the delivery member  11300  can be configured to move relative to the coupling member when the energy storage member  11400  is actuated. Such movement can fluidically couple the delivery member  11300  and the medicament container  11200 , thereby defining a flow path through which the naloxone composition  11220  can be delivered to the patient. 
     In some embodiments, the delivery member  11300  can enhance the delivery of the naloxone composition  11220  thereby improving the efficacy of the naloxone composition  11220 . Similarly stated, in some embodiments, the delivery member  11300  can produce a flow of the naloxone composition  11220  having desired characteristics to enhance the absorption rate of the naloxone composition  11220 , to minimize the delivery of the naloxone composition  11220  to regions of the body in which such delivery is less effective (e.g., the throat, etc.) or the like. 
     For example, in some embodiments, the delivery member  11300  can produce a controlled flow rate of the naloxone composition  11220 . In such embodiments, the delivery member  11300  can include one or more flow orifices, a tortuous flow path or the like, to produce a desired pressure drop and/or to control the flow through the delivery member  11300 . For example, in some embodiments, the delivery member  11300  can be configured to minimize excessive delivery of the naloxone composition  11220 . For example, for intranasal applications, the delivery member  11300  can reduce the likelihood of excess deposition of the naloxone composition  11220  on the mucosal membrane, which can result in a portion of the naloxone composition  11220  being nonabsorbed (e.g., running out of the nose or into the throat). 
     In some embodiments, the delivery member  11300  can be configured to atomize the naloxone composition  11220  to produce a spray for intranasal administration. For example, in some embodiments, the delivery member  11300  can produce an atomized spray of the naloxone composition having a desired spray geometry (e.g., spray angle and/or plume penetration) and/or droplet size distribution. In some embodiments, for example, the delivery member  11300  can include two chambers to allow substantially simultaneous deliver of the naloxone composition  11220  into both nostrils of a patient. Moreover, the delivery member  11300  can be cooperatively configured with the energy storage member  11400  to produce an atomized spray of the naloxone composition having a desired spray geometry and/or droplet size distribution. In this manner, the medicament delivery device  11000  can produce a consistent spray to enhance the efficacy of the naloxone composition  11220  under a wide variety of conditions. 
     In some embodiments, for example, the delivery member  11300  and the energy storage member  11400  can be cooperatively configured such that, when the energy storage member  11400  is actuated, the medicament delivery device  11000  produces an atomized spray of the naloxone composition  11220  having a substantial portion of the droplets therein having size distribution of between about 10 microns and about 20 microns. In this manner, the amount of the naloxone composition  11220  delivered to the lungs (e.g., the amount of smaller droplets that bypass the mucosal membrane) and/or the amount of the naloxone composition  11220  that runs into the throat (e.g., the amount of larger droplets) is minimized. In some embodiments, the delivery member  11300  and the energy storage member  11400  are cooperatively configured to produce a spray of the naloxone composition  11220  having a droplet size distribution wherein approximately 85 percent of the droplets have a size of between approximately 10 microns and 150 microns. 
     As described above, in some embodiments, the energy storage member  11400  is configured to “match” the delivery member  11300 . Said another way, in some embodiments, the energy storage member  11400  is configured to produce the force F8 within a predetermined range to ensure the desired functionality of the delivery member  11300 . Accordingly, the energy storage member  11400  can be any suitable device or mechanism that, when actuated, produces the desired force F8 to deliver the naloxone composition  11220  as described herein. By employing the energy storage member  11400  to produce the force F8, rather than relying on a user to manually produce the delivery force, the naloxone composition  11220  can be delivered into the body at the desired pressure and/or flow rate, and with the desired characteristics, as described above. Moreover, this arrangement reduces the likelihood of partial delivery (e.g., that may result if the user is interrupted or otherwise rendered unable to complete the delivery). 
     In some embodiments, the energy storage member  11400  can be a mechanical energy storage member, such as a spring, a device containing compressed gas, a device containing a vapor pressure-based propellant or the like. In other embodiments, the energy storage member  11400  can be an electrical energy storage member, such as a battery, a capacitor, a magnetic energy storage member or the like. In yet other embodiments, the energy storage member  11400  can be a chemical energy storage member, such as a container containing two substances that, when mixed, react to produce energy. 
     Although the medicament delivery device  11000  is shown and described above as including an energy storage member  11400 , in other embodiments, a kit can include a medicament container containing a naloxone composition that is delivered by a manually-produced force. For example,  FIG. 139  is a schematic illustration of a kit  12000  according to an embodiment. The kit  12000  includes a case  12190 , a medicament container  12200  that contains (i.e., is filled or partially filled with) a naloxone composition  12220 , and a delivery member  12300 . The naloxone composition  12220  can be any of the naloxone compositions shown and described herein. The medicament container  12200  is movably disposed within the case  12190 . More particularly, the medicament container  12200  can be removed from the case  12190  to deliver the naloxone composition  12220  contained therein. 
     Although the medicament container  12200  is shown as being substantially enclosed by and/or disposed within the case  12190 , in other embodiments, the medicament container  12200  can be only partially enclosed by and/or disposed within the case  12190 . In some embodiments, the case  12190  blocks an optical pathway between the medicament container  12200  and a region outside of the case  12190 . Similarly stated, when the medicament container  12200  is disposed within the case  12190 , the case  12190  is obstructs the medicament container  12200  to reduce the amount of light transmitted to the naloxone composition  12220  within the medicament container  12200 . 
     The delivery member  12300 , which can be a needle, an atomizer (e.g., for intranasal delivery, as described above), a mouthpiece or the like, is coupled to the medicament container  12200  and defines, at least in part, a flow path through which the naloxone composition  12220  can be delivered into a body. Although shown as being directly coupled to a distal end portion of the medicament container  12200 , in other embodiments, the delivery member  12300  can be indirectly coupled to the medicament container  12200 , (e.g., via the housing  12100 ). 
     Moreover, in some embodiments, the delivery member  12300  can be coupled to, but fluidically isolated from, the medicament container  12200  prior to actuation of the medicament container  12200  (e.g., by manually depressing a plunger, squeezing a trigger, or the like). In this manner, the medicament delivery device  12000  can be stored for extended periods of time while maintaining the sterility of the naloxone composition  12220  contained within the medicament container  12200 , reducing (or eliminating) any leakage of the naloxone composition  12220  from the medicament container  12200  or the like. This arrangement also reduces and/or eliminates the assembly operations (e.g., the operation of coupling the delivery member  12300  to the medicament container  12200 ) before the medicament delivery device  12000  can be used to administer the naloxone composition  12220 . In this manner, the medicament delivery device  12000  produces a quick and accurate mechanism for delivering the naloxone composition  12220 . Similarly stated by reducing and/or eliminating the assembly operations prior to use, this arrangement reduces likelihood that performance of medicament delivery device  12000  and/or the delivery member  12300  will be compromised (e.g., by an improper coupling, a leak or the like). 
     In some embodiments, the delivery member  12300  can be coupled to the medicament container  12200  via a coupling member (not shown in  FIG. 139 ) having similar functionality to the carrier  9370  shown and described above with respect to the medicament delivery device  9000 . In such an embodiment, the medicament container  12200  and/or the delivery member  12300  can be configured to move relative to the coupling member when the medicament container  12200  is actuated. For example, in use, upon depressing a plunger to actuate the medicament container  12200 , the coupling member can move relative to the medicament container  12200  before a substantial portion of the energy produced by movement of the plunger is exerted on the naloxone composition  12220 . Such movement can fluidically couple the delivery member  12300  and the medicament container  12200 , thereby defining a flow path through which the naloxone composition  12220  can be delivered to the patient. 
     In some embodiments, at least one of the medicament container  12200  and the case  12190  can include an electronic circuit system (not shown in  FIG. 139 ) similar to the electronic circuit systems shown and described herein. In such embodiments, the electronic circuit system can be actuated when the medicament container is removed from the case  12190 . Any suitable mechanism can be used to actuate the electronic circuit system when the medicament container  12200  is removed from the case  12190 . Such mechanisms include those mechanisms disclosed in U.S. Pat. No. 8,172,082, entitled “Devices, Systems and Methods for Medicament Delivery,” filed on Feb. 5, 2007, which is incorporated herein by reference in its entirety. 
     While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods described above indicate certain events occurring in certain order, the ordering of certain events may be modified. Additionally, certain of the events may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. 
     Although the first surface  3341  of the piston member  3330  is shown as being substantially parallel to the second surface  3342  of the piston member  3330 , in other embodiments, the first surface of a movable member can be at any suitable angular orientation to a second surface of the movable member. 
     Although the carrier  3370  is shown as substantially surrounding the medicament container  3200 , in other embodiments, a carrier and/or the contact shoulders (analogous to the first shoulder  3377  and the second shoulder  3381 ) need not substantially surround the medicament container  3200 . For example, in some embodiments, a carrier can be a single piece member that only partially surrounds the flange  3214  of the medicament container  3200 . Similarly stated, in some embodiments, a carrier need not be movable between an opened configuration and a closed configuration, but rather can receive and/or retain the medicament container in a single configuration. 
     Although the carrier  4370  is described above as being configured to accommodate an o-ring or other suitable damping member to reduce the forces exerted on the medicament container  4200  during insertion and/or injection, in other embodiments, any suitable mechanisms or structures for reducing the energy, impulse and/or forces applied to the carrier, the medicament container, the housing and/or the actuation member can be employed. For example, in some embodiments, a carrier can include a deformable portion (e.g., a “crush rib”) configured to deform when contacting the housing during an insertion event. In this manner, the deformable portion can absorb at least a portion of the energy and/or force generated during the impact, thereby reducing the magnitude of the energy, impulse and/or force applied to the medicament container. Similarly, in some embodiments, a portion of a medicament delivery mechanism, such as medicament delivery mechanism  4300  can include a crush rib or an impact portion configured to plastically and/or elastically deform to absorb and/or dampen the forces from the needle insertion operation. 
     In some embodiments, the outer surface  3815  of the needle sheath  3810  can include a cap or cover that has different material properties than the remainder of the needle sheath  3810 . For example, in some embodiments, the outer surface  3815  can be constructed of a material having greater hardness and/or rigidity than the remainder of the needle sheath  3810 . This arrangement allows for sufficient structural rigidity to assembly the needle sheath  3810  within the engagement portion  3720  of the safety lock  3700 . In other embodiments, however, any of the needle sheaths described herein need not include an outer cover or cap. The use of a cap-less design can reduce manufacturing and/or assembly costs. 
     Although the medical injector  3000  is shown above as including a gas container  3410  that is actuated by a puncturer that moves within the housing  3100  with the release member  3550 , in other embodiments a system actuation assembly  3500  can include a puncturer that is substantially fixed within the housing and a gas container that moves within the housing into contact with the puncturer upon actuation of the device. 
     Although the medicament delivery mechanism  5300  is shown above as being a monolithically constructed member (i.e., a “first movable member”), in other embodiments, the medicament delivery mechanism  5300  can include multiple members that are separately constructed and/or that are coupled together. For example, in some embodiments, a medicament delivery mechanism can include a first member that corresponds to the latch portion  5310  and the piston portion  5330 , and a second, separately constructed member that produces a retraction force (e.g., similar to the function of the bias portion  5350 . In such embodiments, for example, second member can be a separately constructed coil spring or the like. 
     Although the medical injector  3000  includes the electronic circuit system cavity  3153 , the gas cavity  3154  and/or the medicament cavity  3157  that are shown and described as being fluidically and/or physically isolated from each other, in other embodiments, any of the electronic circuit system cavity  3153 , the gas cavity  3154  and/or the medicament cavity  3157  can be fluidically coupled to and/or share a common boundary with each other. In some embodiments, for example, a housing can define a single cavity within which a medicament container, an energy storage member and an electronic circuit system are disposed. 
     Any of the devices and/or medicament containers shown and described herein can be constructed from any suitable material. Such materials include glass, plastic (including thermoplastics such as cyclic olefin copolymers), or any other material used in the manufacture of prefilled syringes containing medications. Any of the medicament containers described herein can contain any of the naloxone compositions and/or formulations described herein. 
     Any of the devices and/or medicament containers shown and described herein can include any suitable medicament or therapeutic agent. In some embodiments, the medicament contained within any of the medicament containers shown herein can be a vaccine, such as, for example, an influenza A vaccine, an influenza B vaccine, an influenza A (H1N1) vaccine, a hepatitis A vaccine, a hepatitis B vaccine, a haemophilus influenza Type B (HiB) vaccine, a measles vaccine, a mumps vaccine, a rubella vaccine, a polio vaccine, a human papilloma virus (HPV) vaccine, a tetanus vaccine, a diphtheria vaccine, a pertussis vaccine, a bubonic plague vaccine, a yellow fever vaccine, a cholera vaccine, a malaria vaccine, a smallpox vaccine, a pneumococcal vaccine, a rotavirus vaccine, a varicella vaccine, a rabies vaccine and/or a meningococcus vaccine. In other embodiments, the medicament contained within any of the medicament containers shown herein can be a catecholamine, such as epinephrine. In other embodiments, the medicament contained within any of the medicament containers shown herein can be an opioid receptor antagonist, such as naloxone, including any of the naloxone formulations described in U.S. patent application Ser. No. 13/036,720, entitled “Medicament Delivery Device for Administration of Opioid Antagonists Including Formulation for Naloxone,” filed on Feb. 28, 2011. In yet other embodiments, the medicament contained within any of the medicament containers shown herein can include peptide hormones such as insulin and glucagon, human growth hormone (HGH), erythropoiesis-stimulating agents (ESA) such as darbepoetin alfa, monoclonal antibodies such as denosumab and adalimumab, interferons, etanercept, pegfilgrastim, and other chronic therapies, or the like. In yet other embodiments, the medicament contained within any of the medicament containers shown herein can be a placebo substance (i.e., a substance with no active ingredients), such as water. 
     The medicament containers and/or medicament delivery devices disclosed herein can contain any suitable amount of any medicament or the naloxone compositions disclosed herein. For example, in some embodiments, a medicament delivery device as shown herein can be a single-dose device containing an amount medicament to be delivered of approximately 0.4 mg, 0.8 mg, 1 mg, 1.6 mg or 2 mg. As described above, the fill volume can be such that the ratio of the delivery volume to the fill volume is any suitable value (e.g., 0.4, 0.6 or the like). In some embodiments, an electronic circuit system can include a “configuration switch” (similar to the configuration switch  3974  shown and described above) that, when actuated during the assembly of the delivery device, can select an electronic output corresponding to the dose contained within the medicament container. 
     Any of the medicament containers described herein can include any of the elastomeric members described herein. For example, the medicament container  5200  can include an elastomeric member  5217  that is formulated to be compatible with the medicament contained therein. Although the medical injector  5000  includes a single elastomeric member  5217 , in other embodiments, any number of elastomeric members  5217  can be disposed within the medicament container  5200 . For example, in some embodiments, a medicament container can include a dry portion of a medicament and a fluid portion of the medicament, configured to be mixed before injection. The piston portion  5330  of the medicament delivery mechanism  5300  can be configured to engage multiple elastomeric members  5217  associated with the portions of the medicament. In this manner, multiple elastomeric members  5217  can be engaged to mix the dry portion with the fluid portion of the medicament before the completion of an injection event. In some embodiments, for example, any of the devices shown and described herein can include a mixing actuator similar to the mixing actuators shown and described in U.S. Patent Publication No. 2013/0023822, entitled “Devices and Methods for Delivering Medicaments from a Multi-Chamber Container,” filed on Jan. 25, 2012, which is incorporated herein by reference in its entirety. 
     Any of the medicament containers described herein can include any of the elastomeric members described herein. For example, the medicament container  9200  can include an elastomeric member that is formulated to be compatible with the naloxone composition contained therein, similar to the elastomeric member  7217  shown and described above. 
     Although the electronic circuit system  3900  is shown and described above as having two irreversible switches (e.g., switch  3972  and switch  3973 ), in other embodiments, an electronic circuit system can have any number of switches. Such switches can be either reversible or irreversible. 
     Although the electronic circuit system  3900  is shown and described above as producing an electronic output in response to the actuation of two switches (e.g., switch  3972  and switch  3973 ), in other embodiments, an electronic circuit system can produce an electronic output in response to any suitable input, command or prompt. Suitable input for prompting an output can include, for example, an audible input by the user (e.g., the user&#39;s response to a voice prompt produced by the electronic circuit system), an input from a “start button” depressed by the user, an input from a sensor (e.g., a proximity sensor, a temperature sensor or the like), movement of (e.g., shaking) of the medicament delivery device, or the like. In some embodiments, an electronic circuit system can include a microphone and/or a voice recognition module to detect a user&#39;s vocal input. 
     Although medical devices having two LEDs and an audio output device have been shown, in other embodiments the medical device might have any number of LEDs and/or audio output devices. Additionally, other types of output devices, such as haptic output devices, can be used. In some embodiments, outputs from an electronic circuit system can include, for example, an audible or visual output related to the composition of the medicament (e.g., an indication of the expiration date, the symptoms requiring treatment with the medicament or the like), the use of the medicament delivery device, and/or post-administration procedures (e.g., a prompt to call 911, instructions for the disposal of the device or the like). 
     Any of the medicament delivery devices shown and described herein can include any of the electronic circuit systems shown and described herein. For example, although the medical injector  5000  is shown as being devoid of an electronic circuit system, in other embodiments, the medical injector  5000  can include an electronic circuit system similar to the electronic circuit system  3900  shown and described above with reference to  FIGS. 29-39 . Moreover, although the electronic circuit systems (e.g., the electronic circuit system  3900 ) are shown and described herein as being coupled the housing of the medicament delivery device, in other embodiments, all or a portion of an electronic circuit system can be coupled to a removable cover (e.g., cover  3190 ). For example, in some embodiments, the cover can include an electronic circuit system (the “master ECS”) including an audible output device, and the electronic circuit system can be configured to receive one or more signals from an electronic circuit system (the “slave ECS”) coupled to the medicament delivery device. In this manner, the master ECS can receive indications of when the safety tab has been removed, when the device has been actuated or the like, and can produce an audible output as described herein. In some such embodiments, the master ECS and the slave ECS can be similar to the electronic circuit systems shown and described in U.S. Pat. No. 8,172,082, entitled “Devices, Systems and Methods for Medicament Delivery,” filed on Feb. 5, 2007, which is incorporated herein by reference in its entirety. 
     Although the electronic circuit system  3900  is shown and described above as producing an electronic output in response to the removal of the safety lock  3700  and/or movement of the base  3510 , in other embodiments, any suitable component within a medicament delivery device can function to actuate the electronic circuit system. For example, in some embodiments, a carrier (similar to the carrier  3370 ) can include a protrusion configured to engage a portion of an electronic circuit system such that the electronic circuit system produces an output in response to movement of the carrier. In other embodiments, an electronic circuit system can produce an electronic output in response to the deformation of a portion of a movable member (e.g., the engagement portion  3379  of the carrier  3370 ). In such embodiments, the deformable portion may be configured to engage a portion of the electronic circuit system or may be configured such that a portion of the electronic circuit system is disposed therein (e.g., a copper trace) to activate the electronic circuit system. 
     In some embodiments, the electronic circuit system of the types shown and described herein can be used in either an actual medicament delivery device or a simulated medicament delivery device. A simulated medicament delivery device can, for example, correspond to an actual medicament delivery device and can be used, for example, to train a user in the operation of the corresponding actual medicament delivery device. 
     The simulated medicament delivery device can simulate the actual medicament delivery device in any number of ways. For example, in some embodiments, the simulated medicament delivery device can have a shape corresponding to a shape of the actual medicament delivery device, a size corresponding to a size of the actual medicament delivery device and/or a weight corresponding to a weight of the actual medicament delivery device. Moreover, in some embodiments, the simulated medicament delivery device can include components that correspond to the components of the actual medicament delivery device. In this manner, the simulated medicament delivery device can simulate the look, feel and sounds of the actual medicament delivery device. For example, in some embodiments, the simulated medicament delivery device can include external components (e.g., a housing, a needle guard, a sterile cover, a safety lock or the like) that correspond to external components of the actual medicament delivery device. In some embodiments, the simulated medicament delivery device can include internal components (e.g., an actuation mechanism, a compressed gas source, a medicament container or the like) that correspond to internal components of the actual medicament delivery device. 
     In some embodiments, however, the simulated medicament delivery device can be devoid of a medicament and/or those components that cause the medicament to be delivered (e.g., a needle, a nozzle or the like). In this manner, the simulated medicament delivery device can be used to train a user in the use of the actual medicament delivery device without exposing the user to a needle and/or a medicament. Moreover, the simulated medicament delivery device can have features to identify it as a training device to prevent a user from mistakenly believing that the simulated medicament delivery device can be used to deliver a medicament. For example, in some embodiments, the simulated medicament delivery device can be of a different color than a corresponding actual medicament delivery device. Similarly, in some embodiments, the simulated medicament delivery device can include a label clearly identifying it as a training device. 
     Although various embodiments have been described as having particular features and/or combinations of components, other embodiments are possible having a combination of any features and/or components from any of embodiments where appropriate. For example, any of the devices shown and described herein can include an electronic circuit system as described herein. For example, although the medicament delivery device  4000  shown in  FIGS. 56 and 57  is not shown as including an electronic circuit system, in other embodiments, a medicament delivery device similar to the device  4000  can include an electronic circuit system similar to the electronic circuit system  3900  shown and described above. Although the medicament delivery device  11000  shown in  FIG. 138  is not shown as including an electronic circuit system, in other embodiments, a medicament delivery device similar to the device  11000  can include an electronic circuit system similar to the electronic circuit system  3900  shown and described above.