Patent Publication Number: US-2011056948-A1

Title: Pharmaceutical Container Having Non-Child-Resistant Closure

Description:
BACKGROUND OF THE INVENTION 
     This invention relates in general to pharmaceutical containers. In particular, this invention relates to non-child-resistant closures for pharmaceutical containers. 
     Pharmaceutical containers are used to dispense drugs and other medicines from a pharmacist to patients. Because of the potential for children to gain access to these medicines with potentially dangerous effects, closure devices have been provided with various mechanisms to prevent or deter small children from gaining access to the contents. One popular type of child-resistant (CR) closure and container system is a push and turn type system that includes a cap having an outer shell and an inner seal. While this closure configuration has the intended result of hampering or preventing small children from gaining unauthorized access to medicines, it also has the unintended result of hampering access to medicines by the elderly or physically challenged patients. The difficulty lies in certain users having a lack of manual dexterity and strength to both compress and twist the cap. For this reason, non-child-resistant caps are still in substantial use. 
     Previous non-child-resistant closures, such as traditional snap caps, are easy to open but may not provide adequate sealing to contain liquids or may be inadvertently opened, such as when carried in a purse or pocket. Other non-child-resistant cap configurations may include external threads that engage threads formed on the inner diameter of the container. However, forming threads on containers, particularly on the inner diameter of the containers, increases the cost of manufacture. Other non-child-resistant closure configurations do not provide any indication that they are truly in a closed position. Thus, it would be desirable to provide an improved non-child-resistant closure for pharmaceutical containers. 
     SUMMARY OF THE INVENTION 
     This invention relates to a non-child-resistant closure and container system for a pharmaceuticals. The system comprises a container and a cap configured to cooperate with the container. The container has at least one bayonet structure that includes a leading taper, a recess, and a backstop. The cap has an outer shell that includes a skirt and at least one lug formed thereon. The lug is configured to cooperate with the bayonet structure such that one of an audible signal and a tactile sensation is produced upon closing the cap onto the container. The cap is closed onto the container by rotating the cap until a portion of the lug enters the recess. The lug is further configured to be released from the recess by reverse rotation of the cap causing the lug to move axially relative to the recess. 
     The lug of the cap includes a primary profile and a secondary profile. The primary profile engages the recess and the secondary profile controls the amount of engagement of the lug into the recess. The secondary profile further controls the compression of a resilient inner seal having a spring force characteristic and a spring rate. The amount of engagement of the primary profile into the recess compresses the resilient inner seal. Compression of the resilient inner seal is such that the lug is permitted to be released from the recess by rotation of the cap. Rotation of the cap causes the lug to move axially relative to the recess. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded, perspective view of a closure and container system for pharmaceuticals. 
         FIG. 2  is an enlarged view, in partial cross-section, of the closure and container system of  FIG. 1 . 
         FIG. 3  is an exploded view of an embodiment of a cap of the closure and container system of  FIG. 1 . 
         FIG. 4A  is an enlarged view, in cross-section, of the closure and container system of  FIG. 1  shown in a closed and unlocked orientation. 
         FIG. 4B  is the closure and container system of  FIG. 4A  shown in a closed and locked orientation. 
         FIG. 4C  is an enlarged view, in cross-section, of an embodiment of a closure positioned on the container of  FIG. 1  shown in a closed and locked orientation. 
         FIG. 5A  is a first embodiment of a bayonet and lug closure structure. 
         FIG. 5B  is a second embodiment of a bayonet and lug closure structure. 
         FIG. 5C  is a third embodiment of a bayonet and lug closure structure. 
         FIG. 5D  is a fourth embodiment of a bayonet and lug closure structure. 
         FIG. 5E  is a fifth embodiment of a bayonet and lug closure structure. 
         FIG. 6  is a prior art child-resistant bayonet and lug closure structure. 
         FIG. 7  is a prior art non-child-resistant bayonet and lug closure structure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, there is illustrated in  FIGS. 1 and 2  a closure and container system, shown generally at  10 , that includes a non-child-resistant cap  12  and a container  14 . The container  14  includes a plurality of bayonets  16  spaced around an open end  18  of the container  14  and may be suitable for both child-resistant and non-child resistant closures. The bayonets  16  include a leading taper  20 , a recess  22 , and a backstop  24 . The bayonets  16  are configured to cooperate with a lug  26  that is part of the cap  12 . As shown in  FIG. 3 , the cap  12  includes an outer shell  28  having a skirt  30  that extends from a back portion  32  of the outer shell  28 . The lugs  26 , the skirt  30 , and the back portion  32  are integrally molded to form the outer shell  28 . The lugs  26  are shown spaced around an inner surface of the skirt  30 . The cap  12  further includes a resilient inner seal, shown generally at  34 . Though illustrated as a separate member, the inner seal  34 , or any portions of the inner seal  34 , may be integrally formed with the outer shell  28 . 
     Referring now to  FIGS. 4A and 4B , the inner seal  34  is illustrated having a sealing bead  36  and an edge seal  38 , though any resilient sealing geometry may be used. The resilient characteristic of the inner seal  34  applies a spring force between the outer shell  28  and the container  14  that causes the two structures to separate. The sealing bead  36  is shown in the form of a general “U” or “V” shape, though such a geometry is not required. The sealing bead  36  extends into the opening  18  and seals against the leading edge of the container  14  and may produce a fluid tight seal arrangement. The edge seal  38  may be shaped in a in a “U” or “V” geometry or any other contacting shape such as flat, rounded, “C”-shaped, or any other suitable sealing geometry. The sealing bead  36  and the edge seal  38  may produce the spring force as they are compressed between the outer shell  28  and the container  14 , as shown in  FIG. 4B . Either structure, alone or in cooperation, may generate the separating spring force between the outer shell  28  and the container  14 . In order to generate a spring force, the resilient inner seal  34  is made from an elastomeric material such as, for example, synthetic rubber, urethane, poly vinyl chloride, polyethylene, and the like. 
     Referring now to  FIG. 4C , there is illustrated another embodiment of a closure, shown generally at  12   a , which is similar to the closure  12  described previously. Similar reference numbers will be used to describe features of closure  12   a  that are similar to closure  12 . The closure  12   a  includes an outer shell  28   a  having a skirt  30   a  that extends from a back portion  32   a  of the outer shell  28   a . A plurality of lugs  26   a , similar to lugs  26  or any other lug embodiment described herein, are formed on the inner surface of the skirt  30   a . The lugs  26   a , the skirt  30   a , and the back portion  32   a  are integrally molded to form the outer shell  28   a . The outer shell  28   a  includes an inner seal  34   a  that is also formed integrally with the back portion  32   a . The inner seal  34   a  is shown having a tapered outer surface  36   a  which may also be applied as a taper on the inner surface, though such is not required. The tapered outer surface  36   a  includes an edge seal portion  38   a  that seals against the container  14 . The edge seal portion  38   a  may have either a smooth surface finish or a matte or satin textured finish in order to adjust the coefficient of friction between portions of the container  14  and the closure  12 . 
     The integral inner seal  34   a  includes an anchor section  37   a  that is formed integrally with the outer shell  28   a . The anchor section  37   a  extends from an inner surface of the back portion  32   a  of the outer shell  28   a . In the illustrated embodiment, the anchor section  37   a  is thicker than the edge seal  38   a . The tapered surface  36   a  may extend from the anchor portion  37   a  and provide the inner seal  34   a  with a gradually decreasing cross section. The gradually decreasing cross section of the inner seal  34   a  has a spring rate that applies a sealing force against the container  14  as the closure  12   a  is moved to the closed position of  FIG. 4C . The inner seal  34   a  may be deflected at the edge seal portion  38   a  to create a fluid tight seal. 
     Referring now to  FIG. 5A , in a first embodiment, the lug  26  includes a primary profile  40  and a secondary profile  42 . The primary profile  40  engages the recess  22  of the bayonet  16 . The secondary profile  42  contacts another portion of the bayonet  16  such as the leading taper  20 , near the intersection with the recess  22  shown in  FIG. 5A . Referring again to  FIGS. 4A and 4B , the cap  12  is moved from an unclosed position shown in  FIG. 4A  to a closed and secured position of  FIG. 4B  by twisting the cap  12  relative to the container  14 . As the outer shell  28  is twisted, the lug  26  makes contact with the leading taper  20  of the bayonet  16 . The lug  26  moves along the leading taper  20  which draws the outer shell  28  onto the container  14 . As the outer shell  28  is rotated and drawn onto the container  14 , the inner seal  34  is compressed between the back portion  32  of the outer shell  28  and a portion of the container  14 , such as the rim. As the outer shell  28  is twisted further, the primary profile  40  of the lug  26  enters the recess  22  of the bayonet  16 . The depth of engagement between the primary profile  40  and the recess  22  is controlled by contact between the secondary profile  42  and a portion of the bayonet  16 . As shown in  FIGS. 4B and 5A , the end of the leading taper  20  contacts the secondary profile  42 . Upon closing, the contact of the secondary profile  42  with the bayonet  16  produces at least one of an audible signal or a tactile sensation that indicates the cap  12  is engaged in a closed and secure condition with the container  14 . The audible signal may sound like a “click” and a corresponding “tap” or impulse input to the cap may be felt by the user&#39;s finger tips or palm. 
     To open the cap  12  from the container  14 , the outer shell  28  is twisted relative to the container  14  in the opposite direction of the closing movement. The depth of engagement between the primary profile  40  and the recess  22  is controlled by the secondary profile  42  such that added compression of the inner seal  34  required to disengage the primary profile  40  from the recess  22  can be achieved without requiring the application of a secondary axial force to the outer shell  28 . In other words, the secondary profile  42  limits the spring force generated by the inner seal  34  so that when the cap is unscrewed, the lug  26  disengages from the recess  22 . The lug  26  disengages from the recess  22  without an additional axial force being applied by the user to urge the lug  26  away from engagement with the recess  22 . As shown in  FIG. 6 , such a secondary axial force and deflection, A, is required to disengage a lug  526  of a conventional child-resistant cap from the recess  22  of the container  14 , as will be explained in detail below. Only after the lug  526  of the child-resistant cap of  FIG. 6  is disengaged from the recess  22  by the axial deflection “A” can the lug  526  be rotated to permit removal of the child-resistant closure from the container. In contrast, rotating the non-child-resistant cap  12  provides a sufficient axial compression of the inner seal  34  to permit the lug  26  to disengage the recess  22  without requiring the application of a secondary axial force. 
     The primary profile  40  is offset or spaced apart from the secondary profile such that a depth of engagement “B”, as shown in  FIG. 5A , of the lug  26  with the recess  22  is limited. The depth of engagement of the lug  26  with the recess  22  is a function of the stiffness of the resilient inner seal  34 . As the spring rate (measured, for example, in pounds per inch) of the inner seal  34  becomes higher (i.e., stiffer), the depth of engagement is smaller. This inverse proportion of stiffness to depth of engagement provides a force to compress the seal, with the force being achievable by rotation alone of the outer shell  28 . In one embodiment, the primary profile is offset to permit the lug  22  to project approximately 0.005 inch into the recess  22 . The offset however may be any depth such as within the range of 0.003 to 0.060 inches if desired. 
     Referring now to  FIGS. 5B-5E , there are illustrated various alternative embodiments of lugs where the primary and secondary profiles are engaged with the recess  22  of the bayonet  16 . As shown in  FIG. 5B , a lug  126  has a primary profile  140  that may be a projection extending into the recess  22 , such as a rounded bump. Such a projection may permit a stiffer inner seal member to be used with a greater depth of engagement “B” by providing a less abrupt transition between the primary profile  140  and a secondary profile  142 .  FIG. 5C  shows an alternative primary profile  240  that is a double sided ramp having a lead-in surface  240   a  with a longer length and shallow inclination angle and a retaining surface  240   b  having a steep inclination angle. Such a primary profile may allow for a wider range of seal spring rates to be used while still permitting the cap to be removed by the user only rotating the outer shell. 
       FIGS. 5D and 5E  illustrate alternative embodiments of secondary profiles. As shown in  FIG. 5D , a secondary profile  342  that extends from a lug  326  adjacent to the leading taper  20  of the bayonet  16 . A primary profile  340  abuts the bayonet  16  in a similar manner as the lug  26  of  FIG. 5A .  FIG. 5E  shows another embodiment of a lug  426  having a secondary profile  442  that engages a portion of the backstop  24 . A primary profile  440  abuts the bayonet  16  in a similar manner as depicted in  FIG. 5A . Alternatively, the secondary profile  442  may be combined with any primary profile shape desired. 
     Referring now to  FIG. 6  there is illustrated a cooperating bayonet  16  and lug  526  of a conventional push and turn type child-resistant (CR) closure and container system that includes a cap having an outer shell and an inner seal. The outer shell includes a skirt having lugs formed thereon, similar to the outer shell described above. The lugs  526  are adapted to cooperate with the bayonet structure  16  formed on an outer surface of the container. The bayonet structure includes a leading edge taper or cam surface, a back stop portion, and a recess  22  as previously described above. 
     The cap is aligned on the container so that the lugs may pass vertically between adjacent bayonet structures. Rotating the cap on the container causes the lugs to contact the leading taper of the bayonet structure. As the cap continues to be rotated, the lugs  526  move along the leading taper which draws the outer shell toward the container. The outer shell compresses the inner seal into the opening of the container. The lugs  526  are rotated beyond the taper toward the back stop portion. The lugs  526  are then drawn into the recess  22  by the spring force of the compressed inner seal to lock the cap onto the container. If the cap is rotated relative to the container, without a secondary axial force applied to the cap, the seating of the lug  526  into the recess  22  provides both of an audible signal and a tactile sensation to indicate the lid has been properly secured. The seating of the lug into the recess may also provide one of the audible and tactile indicators to the user in certain instances. Rotating the cap without compressing the cap against the container provides an added confirmation that the cap is properly closed. The inner seal maintains a residual compression to provide a liquid and/or air tight seal. 
     To release the child-resistant cap from the container, a downward force is applied to the cap causing the inner seal to be further compressed from the closed seal state. The lugs  526  are then axially disengaged from the recesses  22  of the bayonet structure  16 . A rotational force is required to slide the lugs around the cam surface on the bayonets and back to the spaces between adjacent bayonets. The torque to rotate the container lid increases with the amount of axial force applied to compress the seal. The axial force is high enough to prevent or frustrate a child&#39;s attempts to open the container. By way of the coefficient of friction between the inner seal and one of the outer shell of the child-resistant cap or the container  14 , the torque to rotate the cap to a removable position also increases while compressing the inner seal. As previously mentioned, certain of the elderly or physically challenged patients may be hampered or even prevented from accessing their medications with these child-resistant closure systems. The difficulty lies in certain users having a lack of manual dexterity and strength to both compress and twist the cap. Depending upon the materials selected for the container and the inner seal and outer shell of the cap, the different coefficients of friction of the contacting materials may add to the difficulties in opening these pharmaceutical containers. 
     Referring now to  FIG. 7 , there is illustrated a cooperating lug  626  and bayonet structure  16  of a prior art non-child-resistant closure and container system. The closure is similar to the CR cap described above and shown in  FIG. 6 . The main difference is that the lug  626  is sized to be larger than the recess  22  to prevent engagement therewith. The lug  626  engages and is moved along the leading taper or cam of the bayonet  16  as described above. However, the lug  626  completely spans the recess  22  when the edge of the lug  626  contacts the back stop. While these closures are more easily twisted to remove, they do not provide any indication that they are completely seated. As such, they may be more susceptible to inadvertent opening in a purse or pocket. Additionally, because of a lack of confidence in closing these containers, users may twist the closure so hard that the lugs  626  are permanently deformed and the cap is no longer operable or fluid tight. 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.