Patent Publication Number: US-8123736-B2

Title: Cap adapters for medicament vial and associated methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The disclosure of the present application shares common subject matter with the disclosure of application Ser. No. 12/368,797, filed on Feb. 10, 2009. 
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     BACKGROUND 
     The present invention relates to devices and methods for withdrawing medicament from a vial. 
     A typical medicament vial includes an enlarged mouth portion forming an access port for removing liquid medicament from the vial. The mouth portion includes an opening that is sealed by a stopper made of an elastomeric material, such as butyl rubber. A closure, typically formed of metal, is crimped over the enlarged mouth portion and the stopper to positively hold the stopper against the opening. The closure has an aperture to expose a central portion of the stopper. To withdraw the liquid medicament from the vial, a syringe needle pierces the stopper to position the distal end of the needle within the liquid medicament inside the vial. Drawing back on the syringe plunger draws liquid out of the vial and into the syringe barrel. 
     SUMMARY 
     This disclosure describes various embodiments of a medicament vial cap adapter configured to facilitate the transfer of a liquid medicament from a vial to a syringe. These embodiments have several features, no single one of which is solely responsible for the desirable attributes of these embodiments. Without limiting the scope of the present embodiments as expressed by the claims that follow, their more prominent features now will be discussed briefly. This summary, and the following detailed description, will provide an understanding of the present embodiments and the advantages they exhibit, including, without limitation, increased protection for the user, better visibility in a low-light environment, and a reduction or elimination of medicament residue on an outer surface of a sealing stopper in the medicament vial. 
     One embodiment of the present cap adapter comprises a transverse wall portion with a first lumen passing through it. A vial-engaging portion of the cap adapter includes a plurality of clamping members that are circumferentially spaced about an edge of the transverse wall portion and that extend distally from the transverse wall portion. The clamping members are configured to snap fit about a mouth portion of the vial to secure the cap adapter to the vial. A spike extends distally from the transverse wall portion and defines a second, lumen passing through the transverse wall portion. The second lumen is spaced from and not in fluid communication with the first lumen. The spike includes a sharp distal tip that is configured to pierce a sealing stopper on the vial. A cone-shaped shield element extends proximally from a vertex defining an inlet port that communicates with the first lumen, the shield element flaring radially outwardly from the inlet port. The shield element is configured to guide a hypodermic needle toward the first lumen, thereby reducing the risk of needlestick to a user handling the vial. 
     Another embodiment of the present cap adapter comprises a transverse wall portion with a first lumen passing through it. A vial-engaging portion of the cap adapter includes a plurality of clamping members that are circumferentially spaced about an edge of the transverse wall portion and that extend distally from the transverse wall portion. The clamping members are configured to snap fit about a mouth portion of the vial to secure the cap adapter to the vial. A light source cooperates with the cap adapter and is configured to illuminate at least a portion of the cap adapter to enhance the visibility of the vial in a low-light environment. 
     Another embodiment of the present cap adapter comprises a transverse wall portion with a first lumen passing through it. A vial-engaging portion of the cap adapter includes a plurality of clamping members that are circumferentially spaced about an edge of the transverse wall portion and that extend distally from the transverse wall portion. The clamping members are configured to snap fit about a mouth portion of the vial to secure the cap adapter to the vial. A secondary sealing member abuts a distal face of the transverse wall portion and seals a distal end of the first lumen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various embodiments of the present cap adapters and associated methods now will be discussed in detail with an emphasis on highlighting the advantageous features. These embodiments depict the novel and non-obvious cap adapters shown in the accompanying drawings, which are for illustrative purposes only. These drawings include the following figures, in which like numerals indicate like parts: 
         FIG. 1  is a perspective view of one embodiment of a cap adapter for a medicament vial in accordance with the present disclosure; 
         FIGS. 2A and 2B  are cross-sectional views of the cap adapter of  FIG. 1 , taken through the line  2 - 2  in  FIG. 1 ; 
         FIG. 3  is an exploded front elevation view of the cap adapter of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the cap adapter of  FIGS. 1-3  in combination with a medicament vial and a syringe; 
         FIG. 5  is a detail view of the portion of  FIG. 4  indicated by the circle  5 - 5 ; 
         FIG. 6  is an exploded cross-sectional view of the cap adapter of  FIGS. 1-3  in combination with a medicament vial; 
         FIG. 7  is a cross-sectional view of the assembled cap adapter and medicament vial of  FIG. 6 ; 
         FIG. 8  is a perspective view of another embodiment of a cap adapter for a medicament vial in accordance with the present disclosure; 
         FIG. 9  is a right side elevation view of the cap adapter of  FIG. 8 ; 
         FIG. 10  is a cross-sectional view of the cap adapter of  FIG. 9 , taken through the line  10 - 10  in  FIG. 9 ; 
         FIG. 11  is an exploded perspective view of the cap adapter of  FIG. 8 ; 
         FIG. 12  is a detail view of the portion of  FIG. 11  indicated by the circle  12 - 12 ; 
         FIG. 13  is a sectioned perspective view of the cap adapter of  FIG. 8 , taken through the line  13 - 13  in  FIG. 8 ; 
         FIG. 14  is a bottom perspective view of the shield portion of the cap adapter of  FIG. 8 ; 
         FIG. 15  is a detail view of the portion of  FIG. 14  indicated by the circle  15 - 15 : 
         FIG. 16  is a rear elevation view of the cap adapter of  FIG. 8 ; 
         FIG. 17  is a cross-sectional view of the cap adapter of  FIG. 16 , taken through the line  17 - 17  in  FIG. 16 ; 
         FIG. 18  is a detail view of the portion of  FIG. 17  indicated by the circle  18 - 18 ; 
         FIG. 19  is a detail view of the portion of  FIG. 17  indicated by the circle  19 - 19 ; 
         FIG. 20  is a front elevation view of another embodiment of a cap adapter for a medicament vial in accordance with the present disclosure; 
         FIG. 21  is a cross-sectional view of the cap adapter of  FIG. 20 , taken through the line  21 - 21  in  FIG. 20 ; 
         FIG. 22  is a perspective view of another embodiment of a cap adapter for a medicament vial in accordance with the present disclosure; 
         FIG. 23  is a front elevation view of the cap adapter of  FIG. 23 ; 
         FIG. 24  is a cross-sectional view of the cap adapter of  FIG. 23 , taken through the line  24 - 24  in  FIG. 23 ; 
         FIG. 25  is an exploded bottom perspective view of another embodiment of a cap adapter, which includes a locking sleeve, in accordance with the present disclosure; 
         FIG. 26  is an exploded top perspective view of the cap adapter of  FIG. 25 ; 
         FIG. 27  is an assembled bottom perspective view of the cap adapter of  FIG. 25 , showing the cap adapter and the locking sleeve in a first relative rotated position; 
         FIG. 28  is an assembled bottom perspective view of the cap adapter of  FIG. 25 , showing the cap adapter and the locking sleeve in a second relative rotated position; 
         FIG. 29  is a cross-sectional view of the assembled cap adapter of  FIG. 27  engaging a medicament vial; 
         FIG. 30  is a cross-sectional view of the assembled cap adapter of  FIG. 28  engaging a medicament vial; 
         FIG. 31  is an assembled bottom perspective view of another embodiment of a cap adapter with a locking sleeve for a medicament vial in accordance with the present disclosure, showing the cap adapter and the locking sleeve in a first relative rotated position; and 
         FIG. 32  is an assembled bottom perspective view of the cap adapter of  FIG. 31 , showing the cap adapter and the locking sleeve in a second relative rotated position. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description describes the present embodiments with reference to the drawings. In the drawings, reference numbers label elements of the present embodiments. These reference numbers are reproduced below in connection with the discussion of the corresponding drawing features. As used in the description below, the terms “proximal” and “proximally” denote a direction toward the user, while the terms “distal” and “distally” denote a direction away from the user. 
       FIGS. 1-3  illustrate one embodiment of the present cap adapter  40  for a medicament vial. ( FIGS. 2A and 2B  are identical to provide sufficient space to show clearly, and without clutter, the numerous reference numbers and lead lines needed to describe the structure illustrated therein.) The cap adapter  40  is configured to facilitate the transfer of liquid medicament from the vial into a syringe, as described in further detail below. With reference to  FIG. 2A , the cap adapter  40  comprises a transverse internal wall portion  42 . An integral conduit portion  43  extends proximally from the transverse internal wall portion  42  and defines a first lumen  44  that passes through the transverse wall portion  42 . The first lumen  44  is located and configured to permit passage of a hypodermic syringe needle during a transfer of liquid medicament from the vial and into the syringe, as explained below. A circumferential axial wall portion  45  extends proximally from a peripheral edge of the transverse wall portion  42 . 
     A vial-engaging portion  46  of the cap adapter  40  comprises a plurality of clamping members  48  that extend distally and substantially axially from an outer peripheral edge of the transverse wall portion  42 . The clamping members  48  are circumferentially separated from each other by a plurality of substantially axial slots  50 . Each clamping member  48  is cantilevered radially from the wall portion  42 . In cross-section ( FIG. 2A ), each clamping member  48  includes a substantially straight portion  54  extending distally from the wall portion  42 , an internally ridged portion  56  and a radially outwardly flaring skirt portion  58 . The clamping members  48  are configured to snap fit about a mouth portion of a standard medicament vial to secure the cap adapter  40  to the vial, as described below. 
     A shield element  60  extends proximally from the transverse wall portion  42 . In the illustrated embodiment, the shield element  60  includes a substantially conical entrance portion  61  ( FIGS. 2A and 2B ) extending proximally from an annular base  68  that is circumferentially surrounded by the axial wall portion  45 , and that has a distal surface that seats against the proximal surface of the transverse wall portion  42 . The conical configuration of the entrance portion  61  of the shield element  60  serves to guide a syringe needle toward the first lumen  44 , thereby to reduce a risk of needlestick to a user handling the vial, as described in further detail below. 
     As shown in  FIGS. 2A and 2B , at the vertex of the conical entrance portion  61  is an inlet port  62  that is in fluid communication with the first lumen  44 . The conical entrance portion  61  flares radially outwardly from the inlet port  62 . In the illustrated embodiment, the shield element  60  is fabricated as a separate piece from the wall portion  42 , but it may be integral therewith or adhesively fixed thereto. If, as shown, the shield element  60  and the transverse wall portion  42  are separate components, the shield element  60  may advantageously be held in place against the transverse wall portion  42  by a circumferential lip or detent  66  that extends radially inwardly over the peripheral edge of the base  68 . 
     A hollow spike  70  extends distally from the distal surface of the transverse wall portion  42 . The interior of the spike  70  defines a second lumen  72 , the proximal portion of which passes through the transverse wall portion  42 . The second lumen  72  is spaced from, and fluidly isolated from, the first lumen  44 . The spike  70  includes a sharp tip  74  at its distal end that is configured to pierce a sealing stopper  138  ( FIG. 4 ) in the mouth portion of the vial, as described below. Just proximal of the tip  74  is a radial outlet port  75  that communicates with the second lumen  72 . As described in further detail below, the spike  70  establishes fluid communication between the ambient atmosphere and the interior of the vial. Ambient air can thus pass into the vial to equalize the fluid pressure on either side of the sealing stopper  138  as medicament is withdrawn from the vial. 
     The cap adapter  40  further includes a vent passage  76  in fluid communication with the second lumen  72  by means of an axial connecting passage  95  that extends through the base  68  of the shield element  60  between a distal end  82  of the vent passage  76  and a proximal end of the second lumen  72 . The vent passage  76  is open to the ambient atmosphere at a proximal end  78  spaced from the second lumen  72 . The vent passage  76  includes a one-way valve or check valve  80  configured to allow air to flow into the vial through the vent passage  76  and the second lumen  72 . The one-way valve  80  is further configured to inhibit the liquid medicament in the vial from escaping through the second lumen  72  and the vent passage  76 . 
     In the illustrated embodiment, the vent passage  76  extends along an outside of the conical entrance portion  61  of the shield  60 . However, those of ordinary skill in the art will appreciate that in other embodiments the vent passage  76  could be located elsewhere. With reference to  FIGS. 2B and 3 , the distal end  82  of the vent passage  76  receives an overflow riser  84 . The overflow riser  84  is substantially cylindrical and includes a space  86  at a distal end  87  ( FIG. 3 ) for receiving a ball  88  ( FIGS. 2B and 3 ) having a diameter that is slightly smaller than an interior diameter of the space  86  so that air can flow past the ball, as discussed below. 
     An intermediate portion of the overflow riser  84  includes a step  90  ( FIG. 2B ) at which the interior diameter of the overflow riser  84  decreases. The diameter of the step  90  is smaller than that of the ball  88  so that the ball  88  creates a seal inside the overflow riser  84  when it rests against the step  90 , as when the cap adapter  40  is inverted from the orientation shown in  FIG. 2B . In the inverted orientation, engagement of the ball  88  against the step  90  substantially prevents liquid medicament from escaping to ambient through the vent passage  76 . Thus, the ball  88  and the overflow riser  84  together comprise a ball valve  91  ( FIG. 2B ) that allows flow in only one direction, from the ambient atmosphere into the vial. The operation of the ball valve  91  is discussed in greater detail below. 
     As best shown, for example, in  FIGS. 2B and 3 , the overflow riser  84  has a proximal end  92  that receives a duckbill valve  94 . The duckbill valve  94 , the structure of which is well-known, to those of skill in the art, is oriented so that it allows fluid flow in only one direction (i.e., distally), through the vent passage  76 , from the ambient atmosphere into the vial. Like the ball valve  91 , the duckbill valve  94  inhibits the passage of the liquid medicament from the vial to the ambient environment, through the vent passage  76 . Thus, together the ball valve  91  and the duckbill valve  94  provide redundant seals that greatly reduce the likelihood that any medicament will leak out of the vial and the cap adapter through the vent passage  76 . The interior space  86  of the overflow riser  84  provides a chamber for receiving and capturing any proximal backflow of medicament through the second lumen  72  and the internal axial passage  95 . The slightly smaller diameter of the ball  88  as compared to the ball receiving space  86  enables any medicament that enters the overflow riser  84  to travel back down into the vial when the vial is held right-side up (i.e., the orientation shown in  FIGS. 2A and 2B ). 
     The vent passage  76  advantageously enables air to flow from the ambient atmosphere into the vial to equalize the pressure on either side of the sealing stopper  138  and to facilitate withdrawal of medicament from the vial, as discussed in further detail below. From the ambient atmosphere, air flows into the vent passage  76 , through the duckbill valve  94  and into the overflow riser  84 . Properties of the duckbill valve  94  can be tailored to produce a desired cracking pressure at which the duckbill valve  94  opens to allow airflow therethrough. The air then flows through the overflow riser  84  and past the ball  88 . Even if the cap adapter  40  is inverted so that the ball  88  rests against the step  90 , air may flow past the ball  88  if a pressure differential across the ball  88  is greater than a cracking pressure to cause the ball  88  to momentarily lose sealing contact with the step  90 . Properties of the ball  88  can be tailored to produce a desired cracking pressure. Once past the step  90 , air may flow around the ball  88 , since it is smaller in diameter than the internal diameter of the space  86  in the overflow riser  84 . The air then passes into and through the axial internal passage  95 , into and through the second lumen  72 , and then through the radial outlet port  75  and into the vial. 
     The vent passage  76  may include in its interior an optional tubular filter seat  96  upstream from (i.e., proximally from) the duckbill valve  94 . If present, the filter seat  96  advantageously has a distal portion  100 , having a first outside diameter, that is received in the proximal end of the overflow riser  84 , and to which the upstream (proximal) end of the duckbill valve  94  is fixed for fluid communication therewith. The filter seat  96  has a proximal portion  98 , with a second outside diameter larger than the first outside diameter of the distal portion  100 , that receives an optional filter  102 . The filter  102  removes contaminants and pathogens from ambient air passing through the vent passage  76 . The filter  102  may optionally be treated with an anti-microbial substance, of a type well-known in the art. The filter  102  seats against a shoulder  104  ( FIG. 2B ) formed at the junction of the distal portion  100  and the proximal portion  98  to prevent the filter  102  from being sucked down toward the overflow riser  84  by inrushing air. The filter  102  may be replaceable, either separately from, or together with, the filter seat  96 . 
     With continued reference to  FIGS. 2B and 3 , a secondary sealing member  106  may optionally be provided on the distal, surface  108  of the transverse wall portion  42  so as to seal a distal end  110  of the first lumen  44 . The secondary sealing member  106  is formed of an elastomeric material, and it is located and configured to seat against the exterior surface of the sealing stopper  138  on the vial when the cap adapter  40  is secured about the mouth portion of the vial, as discussed in further detail below. In the illustrated embodiment, the secondary sealing member  106  is shaped substantially as a stepped disk, including a thickened central portion  112  circumferentially surrounded by a thinner portion  114 . The central portion  112  seals the distal end  110  of the first lumen  44 . It will be appreciated that the secondary sealing member  106  may have other configurations, such as a constant thickness, a smaller diameter, etc. 
     With continued reference to  FIGS. 2B and 3 , the illustrated cap adapter  40  may further comprise an optional light source  116  configured to illuminate at least a portion of the cap adapter  40 . In the illustrated embodiment, the light source  116  comprises a chemiluminescent ring  116  that extends around the base portion  68  of the shield  60 , substantially surrounding the first lumen  44 . The circumferential axial wall portion  45  extends proximally from the edge  52  of the wall portion  42  and surrounds the light source  116 . 
     With reference to  FIGS. 1 and 3 , the axial wall portion  45  connects to the transverse wall portion  42  at a plurality of discrete locations  118 , creating a plurality of first gaps  120  that separate the axial wall portion  45  from the transverse wall portion  42 . A plurality of second gaps  122  extend perpendicularly to the plurality of first gaps  120  and separate sections  124  of the axial, wall portion  45  from one another. The gaps  120 ,  122  allow the sections  124  to readily flex inwardly under a radial squeezing force provided around the periphery of the axial wall portion  45 . A user can, for example, provide a squeezing force by wrapping his or her thumb and forefinger around the axial wall portion  45 . The squeezing force causes the sections  124  to bear against the light source  116 . A threshold squeezing force induces a chemical reaction within the chemiluminescent ring  116  that produces light. 
     In certain embodiments, the cap adapter  40  is constructed of one or more translucent materials. For example, the cap adapter  40  may be constructed of polycarbonate, acrylic, polypropylene, styrene, or any other suitable plastic material. When the light source  116  is illuminated, light is transmitted through the cap adapter to provide an advantageous visual cue to a user at night or in a low ambient light environment. Thus, the user may reliably guide a syringe needle into the first lumen  44  when there is little or no ambient light, further reducing the risk of needlestick to the user. 
     In certain embodiments, portions of the cap adapter  40  may be constructed from opaque materials, or treated to reduce or eliminate the ability to transmit light. For example, on a darkened battlefield it may be advantageous to reduce the visibility of the cap adapter  40  to others besides the user. Thus, in certain embodiments, substantially all portions of the cap adapter  40  other than the interior  126  ( FIGS. 1 ,  2 A and  2 B) of the shield  60  may be constructed of or treated with an opaque or semi-opaque material. To the user looking into the interior  126  of the shield  60  from the proximal side, the shield  60  will appear to glow and thus guide the user to the first lumen  44 . 
       FIG. 4  illustrates the cap adapter  40  of  FIGS. 1-3  engaging a medicament vial  128  and a syringe  130 .  FIG. 5  illustrates a detail view of the portion of  FIG. 4  indicated by the circle  5 - 5 . With reference to  FIG. 5 , the clamping members  48  extend, around the mouth portion  132  of the vial  128 . The straight portion  54  of each clamping member  48  extends along a flat side of an enlarged portion  134  of the mouth portion  132 . The straight portions  54  may abut the enlarged mouth portion  134  to reduce relative lateral movement of the vial  128  and the cap adapter  40 . The internally-ridged portion  56  extends around an underside  136  of the enlarged mouth portion  134  to resist relative axial movement of the cap adapter  40  away from the vial  128 . Since the clamping members  48  are flexible, however, and since they are separated from one another by the gaps  50  ( FIGS. 2A and 3 ), the cap adapter  40  may be removed from the vial  128  by applying sufficient oppositely directed axial forces to the vial  128  and the cap adapter  40 . 
     With continued reference to  FIG. 5 , the spike  70  penetrates the sealing stopper  138  and establishes fluid communication between the interior  140  of the vial  128  and the vent passage  76  via the second lumen  72  and the axial passage  95 . The spike  70  thus enables ambient air to enter the vial  128  as medicament is withdrawn. The entering air equalizes fluid pressures on opposite sides of the sealing stopper  138 , making it easier for the user to withdraw liquid from the vial  128  since he or she does not have to overcome a vacuum force tending to pull the syringe plunger  142  ( FIG. 4 ) back into the syringe barrel  144 . As discussed above, in certain embodiments the filter  102  advantageously reduces the likelihood of contaminants entering the vial with the incoming ambient air  128 . Further, the valves  91 ,  94  reduce the likelihood that the medicament within the vial  128  will escape to the ambient. 
     With continued reference to  FIG. 5 , the secondary sealing member  106  abuts against the exterior surface  146  of the vial sealing stopper  138 . A syringe needle  148  extends through the first lumen  44 , penetrates the secondary sealing member  106  and the sealing stopper  138 , and extends into the vial interior  140 . The user may withdraw medicament from the vial  128  by positioning the distal tip  150  of the needle  148  within the liquid and drawing back on the plunger  142 . The user may then withdraw the needle  148  from vial  128  to perform an injection. 
       FIGS. 4-7  illustrate one embodiment of a method of using the present cap adapter  40  to withdraw medicament from a vial  128 . With reference to  FIG. 6 , the user positions the vial-engaging portion  46  adjacent the mouth portion  132  of the vial  128  with the skirt portion  58  facing the enlarged portion  134 . The user then applies digital pressure to force the vial  128  and the cap adapter  40  together. With reference to  FIGS. 6 and 7 , as the vial  128  and the cap adapter  40  come together, the sharp tip  74  of the spike  70  penetrates the sealing stopper  138 . The clamping members  48  expand radially as the ridge portion  56  passes over the enlarged portion  134 . When the ridge portion  56  reaches the underside  136  of the mouth portion  132 , the vial-engaging portion  46  snaps onto the vial  128  as shown in  FIG. 7  to create a vial/cap assembly  152 . In the vial/cap assembly  152 , the secondary sealing member  106  abuts against the exterior (proximal) surface of the sealing stopper  138 , and the spike  70  establishes fluid communication between the interior  140  of the vial  128  and the vent passage  76 , as described above. 
     The user then grasps the vial/cap assembly  152 , for example, by wrapping his or her thumb and forefinger around the cap adapter  40  in the region of the axial wall portion  45  and/or the region of the vial-engaging portion  46 . In this configuration, most if not all, of the user&#39;s hand and fingers are positioned behind the conical entrance portion  61  of the shield element  60 . If the user requires additional light, such as in a low ambient light environment, the user squeezes the axial wall portion  45  to activate the chemiluminescent ring  116 . 
     With reference to  FIG. 5 , using the shield element  60 , and, if necessary, the light source  116 , the user guides the needle  148  into the first lumen  44 . The entrance portion  61  of the shield  60  advantageously guides the distal tip  150  of the needle  148  toward the first lumen  44  while at the same time forming a barrier between the sharp needle tip  150  and the user&#39;s hand and fingers. The user is thus well protected from accidental needlestick. The shield element  60  may be constructed of any suitable material that substantially prevents the needle from piercing the shield  60  under conditions of anticipated use. The user is thus unlikely to be stuck by a needle passing completely through the shield  60  and into the user&#39;s hand. 
     Guiding the needle into the first lumen  44 , the user pierces the secondary sealing member  106  and the sealing stopper  138  to insert the needle tip  150  into the vial  128  as shown in  FIGS. 4 and 5 . The user then withdraws a desired amount of medicament from the vial  128  by positioning the distal tip  150  of the needle  148  within the liquid and drawing back on the plunger  142 . The user then withdraws the needle  148  from the vial  128  through the sealing stopper  138  and the secondary sealing member  106 . Advantageously, the abutment of the secondary sealing member  106  and the sealing stopper  138  creates a fluid seal that prevents the liquid medicament from being deposited on the outer surface  146  of the sealing stopper  138  through the tip  150  of the needle  148  as it passes the sealing stopper  138 . The abutment thus reduces the likelihood that medicament residue will be left on the exterior surface  146  of the sealing stopper  138 , which could result in contamination of the environment by such residue. 
     It will be appreciated that the shield element  60  could have a shape different from the illustrated embodiments in which it is substantially cone-shaped. For example, the shield  60  could include an outwardly flared portion in the region near the wall portion  42  and a substantially cylindrical portion adjoining the flared portion at a location spaced proximally from the wall portion  42 . Substantially any shape that guides the needle toward the first lumen  44  and or protects the user from needlestick would be suitable. 
       FIGS. 8-19  illustrate another embodiment of die present cap adapter  160  for a medicament vial. The cap adapter  160  is similar in many respects to the cap adapter  40  described above and illustrated in  FIGS. 1-7 . The cap adapter  160 , however, includes a light source  162  comprising a light-emitting diode (LED)  162  ( FIGS. 10-13 ). A power source  164 , such as a battery  164 , provides power to light the LED  162 . With reference to  FIGS. 9-13 , the LED  162  and the battery  164  reside between the base  166  of the shield  168  and the wall portion  42 . With reference to  FIGS. 14 and 15 , the shield base  166  includes cavities  170 ,  172  to accommodate the LED  162  and the battery  164 , respectively. 
     With reference to  FIGS. 11 and 12 , the LED  162  includes first electrical leads  174  extending in opposite directions from the LED  162 , and the battery  164  includes second electrical leads  176  extending in opposite directions from the battery  164 . The first and second electrical leads  174 ,  176  extend toward each other inside the curved interior of the axial wall portion  178 . The first and second electrical leads  174 ,  176  overlap ( FIG. 12 ), but do not contact each other ( FIGS. 16-19 ). Thus, in an initial configuration no power flows from the battery  164  to the LED  162 . 
     With reference to  FIGS. 16 and 17 , the axial wall portion  178  includes first and second opposed tabs  180 , which flare outwardly from the axial wall portion  178  at a position proximally spaced from the wall portion  42 . The tabs  180  provide a contoured surface for the user&#39;s thumb and forefinger. With reference to  FIGS. 18 and 19 , gaps  182  space the tabs  180  from the wall portion  42  in the areas beneath the tabs  180 . The gaps  182  facilitate the flexing of the axial wall portion  178  inwardly when the user squeezes the tabs  180 . With reference to  FIGS. 18 and 19 , each of the tabs  180  includes a conductive layer  184  on its inward surface. Squeezing the tabs  180  brings the conductive layer  184  into contact with the first and second electrical leads  174 ,  176 , completing the circuit that begins the flow of power from the battery  164  to the LED  162  and illuminates the LED  162 . When the user releases the squeezing force on the tabs  180 , the circuit is broken and the LED  162  darkens. The cap adapter  160  can thus advantageously be illuminated and darkened repeatedly. Not only does this feature prolong the lifespan of the cap adapter  160 , but it also enhances the utility of the cap adapter  160  in environments where it is advantageous for the cap adapter  160  to be illuminated only intermittently for short periods of time, such as on a darkened battlefield. 
     With reference to  FIGS. 8 ,  17  and  18 , in certain embodiments the cap adapter  160  may be initially shipped with a removable pull tab  186 . The pull, tab  186  is made of a ribbon or tape of insulative material, and it provides an insulator between the conductive layer  184  on one of the tabs  180  and the adjacent first and second electrical leads  174 ,  176 , as shown in  FIG. 18 . The tab  186  thus prevents inadvertent contact between the leads  174 ,  176  and the conductive layer  184 . Inadvertent squeezing forces applied to the tabs  180  thus do not cause the LED  162  to illuminate, which preserves the lifespan of the battery  164 . To use the cap adapter  160  for the first time, the user removes the pull tab  186  by grasping the protruding portion and pulling. In certain embodiments, removable pull tabs  186  may be provided for both tabs  180  of the cap adapter  160 . 
       FIGS. 20 and 21  illustrate another embodiment of the present cap adapter  200  for a medicament vial. The cap adapter  200  is similar to the cap adapter  40  described above and illustrated in  FIGS. 1-7 . The cap adapter  200 , however, does not include a spike comprising a second lumen. The cap adapter  200  further does not include a vent passage, filter, secondary sealing member, or axial connecting passage. The cap adapter  200  of  FIGS. 20 and 21  is thus advantageously less expensive to manufacture than the cap adapters  40 ,  160  described, above, because it is less complex. Further, the cap adapter  200  of  FIGS. 20 and 21  advantageously includes a needle entrance lumen  202  that is larger than the first lumen  44  of the cap adapter  40  of  FIGS. 1-7 . 
     To withdraw medicament from a vial using the cap adapter  200  of  FIGS. 20 and 21 , the user secures the cap adapter  200  over the medicament vial substantially as described above with respect to the embodiment of  FIGS. 1-7 . By contrast, however, there is no step of a spike penetrating a sealing stopper on the vial when using the cap adapter  200  of  FIGS. 20 and 21 . The user then inserts a syringe needle through the secondary seal  106  ( FIG. 21 ) and the vial sealing stopper and into the interior of the vial. The larger lumen  202  advantageously provides a larger target for the user as he or she guides the syringe needle. The user may withdraw liquid from the vial by drawing back on the syringe plunger after the needle has been, inserted into the vial. To facilitate easy drawback of the plunger, the user may pressurize the vial by drawing the plunger back prior to penetrating the secondary seal and the vial sealing stopper, and then injecting air into the vial. 
       FIGS. 22-24  illustrate another embodiment of the present cap adapter  210  for a medicament vial. The cap adapter  210  is needleless, meaning that it is adapted to operate with a syringe having no hypodermic needle. With reference to  FIG. 24 , the cap adapter  210  includes a transverse wall portion  212  having a central orifice  214  and a vial-engaging portion  216  extending distally from the wall portion  212 . The cap adapter  210  further includes a light source  218 , which in the illustrated embodiment is a chemiluminescent ring  218  similar to that described above. 
     A hollow spike  220  extends distally from the transverse wall portion  212 , terminating in a sharp distal tip  215 . The interior of the spike  220  defines a lumen  217  that is aligned with and in fluid communication with the central orifice  214 . The lumen  215  terminates in an inlet port  219  proximal to the distal tip  215 . When the cap adapter  210  is secured, to a medicament vial, the distal tip  215  of the spike  220  pierces the vial sealing stopper  138  and opens fluid communication between the interior of the vial and the central orifice  214 . 
     A female luer fitting  222  extends proximally from the wall portion  212 . The interior of the female luer fitting  222  includes an internal annular shoulder  226  between a distal, portion  228  having a first inside diameter and a proximal portion  230  having a second inside diameter that is less than the first inside diameter. The interior of the female luer fitting  222  receives a resilient elastomeric sealing member  232  that conforms to the interior of the female luer fitting  222 . The sealing member  232  includes an external annular shoulder  233  that seats against the internal annular shoulder  226  of the female luer fitting  222  to fix the axial position of the sealing member  232  relative to the female luer fitting  222 . The sealing member  232  has a distal surface that seats against the proximal surface of the transverse wall  212 , and it has an interior cavity  234  with an open distal end that communicates with the central orifice  214  of the transverse wall  212 . The proximal portion of the sealing member  232  includes a slit  235  that opens fluid, communication into the interior cavity  234  and through the sealing member  232  when forced open, as described below. 
     The proximal end of the female luer fitting  222  is configured to receive a male luer fitting (not shown) that is fixed to the distal end of a needleless syringe (not shown). As is well-known in the art, the male luer fitting is threaded for engagement with a thread  236  on the female luer fitting  222 . When the male luer fitting is threaded into the female luer fitting  222 , it forces open, the slit  235  in the sealing member  232 . With the syringe engaging the female luer fitting  222  and the sealing member  232  forced open, fluid communication is established between the cavity  234  and the syringe. The syringe can thus withdraw liquid from a vial to which the cap adapter  210  is attached. 
       FIGS. 25-30  illustrate another embodiment of the present cap adapter  250  for a medicament vial  128 . The cap adapter  250  includes a vial-engaging element  260  that is similar in many respects to the cap adapter  40  described above and illustrated in  FIGS. 1-7 . For instance, the vial-engaging element  260  includes a transverse wall  252  having a first lumen  254  extending axially through its center. A spike  256 , defining a second lumen  258  ( FIGS. 26 and 29 ), extends distally from the transverse wall  252 , at a position radially offset from the first lumen  254 . A circumferential axial wall  264  extends proximally from the transverse wall  252 , and a plurality of clamping members  262  extend, distally from the periphery of the transverse wall  252 . The vial-engaging element  260  may advantageously include a shield element and a one-way valve, as described above with respect to the cap adapter  40  of  FIGS. 1-7 . However, for clarity the shield element and the one-way valve have been omitted from  FIGS. 25-30 . 
     In contrast to the embodiments described above, which may include as many as six or more closely spaced clamping members  48 , the vial-engaging element  260  of the cap adaptor  250  of  FIGS. 25-30  advantageously includes no more than three or four widely spaced clamping members  262 . It will be appreciated that the present cap adapters  40 ,  160 ,  200 ,  210 ,  250  may include any number of clamping members, and the illustrated configurations are not limiting. 
     As best shown in  FIGS. 25-27 , the cap adapter  250  further includes a locking sleeve  266 . The locking sleeve  266  is substantially cylindrical, and includes a proximal transverse wall  268  having a central aperture  270  ( FIG. 26 ). A secondary seal  272 , which seats against a distal surface of the transverse wall  252 , includes an off-center opening  274  that receives the spike  256 . The transverse wall  268  of the locking sleeve  266  is fixed to the interior of a circumferential rim  278  by a plurality of radial spokes  279  separated by circumferentially spaced slots  276 . The locking sleeve  266  has an outer surface  280  that may advantageously include a plurality of circumferentially-spaced depressions  282  that provide gripping surfaces for the user when relatively rotating the vial-engaging element  260  and the locking sleeve  266 , as described in further detail below. 
     With reference to  FIGS. 27 and 29 , in the assembled cap adapter  250  the transverse wails  252 ,  268  of the vial-engaging element  260  and the locking sleeve  266 , respectively, abut one another. In this configuration, the clamping members  262  of the vial-engaging element  260  extend through the slots  276  in the transverse wall  268  of the locking sleeve  266 , and the spike  256  extends through the aperture  270  of the locking sleeve  266  and the aperture  274  of the secondary seal  272 . A proximal inner edge of the locking sleeve  266  includes a lip or detent  284  that extends radially inwardly so as to engage the periphery of the proximal surface of the transverse wall  252  of the vial-engaging member  250 , thereby to prevent the separation of the cap adapter components in the axial direction. 
       FIG. 27  illustrates the cap adapter  250  and locking sleeve  266  in an assembled, unlocked configuration. An inner surface  286  of the locking sleeve  266  includes three circumferentially spaced elevated surfaces  288 . The elevated surfaces  288  are configured and located so as to engage the clamping members  262 , as described in detail below. 
     With continued reference to  FIG. 27 , each of the elevated surfaces  288  includes a ramped surface  290  that extends axially, and a clamping surface  292  that extends circumferentially and faces distally. When the vial-engaging element  260  and the locking sleeve  266  are rotated relative to one another, as indicated by the oppositely directed arrows in  FIG. 27 , causing the clamping members  262  to ride up over the ramped surfaces  290  and onto the elevated surfaces  288 , which flexes the clamping members  262  radially inward. After riding over the elevated surfaces  288 , the clamping members  262  pass over radial locking surfaces  294 , which extend substantially perpendicularly to the inner surface  286  of the locking sleeve  266 . Passing over the locking surfaces  294 , the clamping members  262  snap radially outward into retaining cavities  296 , as shown in  FIG. 28 . Once the clamping members  262  are located in the retaining cavities  296 , end walls  298  of the slots  276  prevent further relative rotation of the vial-engaging element  260  and the locking sleeve  266 , and the radial locking surfaces  294  prevent reverse relative rotation. 
     As the clamping members  262  pass over the radial locking surfaces  294 , a leading edge  300  of each clamping member  262  engages a corresponding clamping surface  292 . The clamping surfaces  292  are ramped, so that as the vial-engaging element  260  continues rotating relative to the locking sleeve  266 , the vial-engaging element  260  is forced distally relative to the locking sleeve  266 . This relative axial movement is illustrated, in  FIGS. 29 and 30 . 
       FIG. 29  illustrates the cap adapter  250  engaging a medicament vial  128 . The cap adapter  250  is in the unlocked position of relative rotation, which is illustrated in  FIG. 27 . In this configuration, the spike  256  extends through the sealing stopper  138 , and the clamping members  262  secure the cap adapter  250  to the medicament vial  128  as described above with respect to the previous embodiments. The secondary seal  272  may abut the sealing stopper  138 , or it may be closely spaced therefrom as shown in  FIG. 29 . To further secure the cap adapter  250  to the medicament vial  128 , the user rotates the locking sleeve  266  math respect to the vial-engaging element  260  in the manner described with respect to  FIGS. 27 and 28 . With reference to  FIG. 30 , which illustrates the locked position of relative rotation, the clamping members  262  abut the elevated surfaces  288 , preventing the clamping members  262  from flexing radially outwardly. The cap adapter  250  is thus locked onto the medicament vial  128 . Further, the relative axial movement of the vial-engaging element  260  and the locking sleeve  266 , described above, forces the secondary seal  272  distally into firm abutting engagement with the sealing stopper  138 . The secondary seal  272  thus creates a substantially fluid-tight seal against the proximal surface of the sealing stopper  138 . Once the cap adapter  250  is in the illustrated locked configuration, the user can withdraw medicament from the vial  128  in the same manner as described above with respect to the cap adapter  40  of  FIGS. 1-7 . Because the locking surfaces  294  ( FIG. 28 ) prevent reverse relative rotation of the vial-engaging element  260  and the locking sleeve  266 , and because the elevated surfaces  288  prevent outward radial flexing of the clamping members  262 , the cap adapter  250  is permanently secured to the vial  128  and cannot be removed without damaging the cap adapter  250  and/or the vial  128 . The cap adapter  250  can thus substantially reduce the likelihood that the contents of the vial  128  will escape into the ambient environment. 
       FIGS. 31 and 32  illustrate another embodiment of the present cap adapter  310  for a medicament vial. The cap adapter  310  is identical to the cap adapter  250  illustrated in  FIGS. 25-30 , except for the structure on the interior surface of the locking sleeve. Specifically, the cap adaptor  310  includes a locking sleeve  314  that includes, on its interior surface, a plurality of circumferentially-spaced locking structures, each of which comprises an elevated surface  320  adjacent the proximal end of the sleeve  314 , and a detent structure, adjacent a distal edge of the elevated surface. The detent structure is radially recessed relative to the elevated surface  320 ; that is, it has a lower elevation relative to the interior surface of the locking sleeve  314  than does the elevated surface  320 . Each detent structure comprises a first, upper step  318  and a second, lower step  322 , separated by an axial detent lip  312 . Each of the locking structures also includes an axially-extending ramped edge  316  that is contiguous with the elevated surface  320  and the first step  318 . 
     When the vial-engaging element  260  and the locking sleeve  314  are rotated relative to one another, as indicated by the oppositely directed arrows in  FIG. 31 , each of the clamping members  262  rides up over a corresponding ramped edge  316  and onto an adjacent first step  318 . The first steps  318  flex the clamping members  262  radially inward. After riding over its associated first step,  318 , each of the clamping members  262  passes over a detent lip  312  and onto the adjacent (and lower) second step  322 . Passing over the lips  312 , the clamping members  262  snap radially outward onto the second steps  322 , as shown in  FIG. 32 . Once the clamping members  262  are seated on the second steps  322 , the lips  312  resist, but do not prevent, reverse relative rotation. The embodiment  310  of  FIGS. 31 and 32  can thus be removed from the medicament vial  128  by reverse relative rotation of the vial-engaging element  260  and the locking sleeve  314 . The lips  312  provide a tactile cue that the cap adapter  310  is fully secured on the medicament vial  128 , and also provide light resistance against accidental reverse relative rotation. 
     The above description presents the best mode contemplated for earning out the present cap adapters and associated methods, and of the manner and process of making and using them, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use these cap adapters. These cap adapters and associated methods are, however, susceptible to modifications and alternate constructions from that discussed above that are fully equivalent. Consequently, these cap adapters and associated methods are not limited to the particular embodiments disclosed. On the contrary, these cap adapters and associated methods cover all modifications and alternate constructions coming within the spirit and scope of the cap adapters and associated methods as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the cap adapters and associated methods.