Abstract:
The disclosed subject matter relates to an injection nozzle cap capable of being fittedly inserted in a space between an injection nozzle of a syringe having a cylindrical, female luer-lock fitting and the female luer-lock fitting. The injection nozzle cap can include a base portion and a cylindrical leg portion extending downwardly of the base portion. The cylindrical leg portion may include, on an outer wall thereof, a substantially annular, bulged portion and/or a ring. There can also be provided nozzle caps for pre-filled syringes, which can be securely and automatically capped at high speed on syringes having female luer-lock fittings without occurrence of their falling-off, for example, during filling of a drug solution.

Description:
[0001]    This application claims priority under 35 U.S.C. 119 to Japanese patent application no. JP2006-310750, filed in Japan on Nov. 16, 2006, and priority under 35 U.S.C. 120 to application no. PCT/JP2007/072079, filed on Nov. 14, 2007. The contents and subject matter being incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The disclosed subject matter relates to an injection nozzle cap (which may hereinafter be simply called “cap”) for a pre-filled syringe (which may hereinafter be simply called “syringe”) having a female luer-lock fitting, and more specifically to a syringe cap which permits easy capping and which does not easily fall off, for example, upon filling a drug solution. 
       BACKGROUND ART 
       [0003]    In recent years, pre-filled syringes (syringes usable as containers) with drug solutions or nutrient infusions are used which are filled and sealed beforehand in syringe barrels of syringes. The use of these syringes makes it possible to avoid false handling, contamination by mixed foreign matter, damage to syringe needles and the like upon drawing drug solutions from containers such as ampoules or vials into syringes, and also to save the labor and time needed to draw thixotropic (thixotropy-possessing) drug solutions or the like in case of emergencies. 
         [0004]    A pre-filled syringe is provided on a head portion thereof with a female luer-lock fitting formed to facilitate the connection of an extension tube, three-way cock or syringe needle for mixing a drug in an infusion solution or the like or injecting a high-viscosity drug or the like. 
         [0005]    With reference to  FIG. 4 , the female luer-lock fitting of the pre-filled syringe  20  will be described. The female luer-lock fitting  7  surrounds an injection nozzle  8 , and is comprised of a cylinder which is lower in height than the injection nozzle  8  and is concentric with the injection nozzle  8 . A helical ridge  9  is formed on an inner peripheral surface of the cylinder. An extension tube (not shown), which is to be connected to the fitting, is provided at a free end thereof with a cylindrical connection member to be brought into threaded engagement with the nozzle  8  and female luer-lock fitting  7  of the syringe  20 . By threadingly fitting this connection member into a space between the injection nozzle  8  and the female luer-lock fitting  7 , the syringe  20  and the extension tube can be connected together. 
         [0006]    Upon producing a pre-filled syringe, a cap  10  is firstly fitted on the injection nozzle  8  and female luer-lock fitting  7 . This fitting operation of the cap  10  is generally called “capping”. The syringe  20  with the cap  10  capped thereon is sterilized with heat, steam, electron beam or the like, and at a pharmaceutical company or the like, a drug solution is filled and sealed in the syringe  20 . 
         [0007]    Employed as the cap  10  for the conventionally employed syringe  20  provided with the female luer-lock fitting  7  is a rubber plug or closure having a cylindrical leg portion  2 , which is to be inserted between the female luer-lock fitting  7  and the nozzle  8 , and a base portion  1  holding the cylindrical leg portion  2  thereon. 
         [0008]    Upon producing pre-filled syringes, such caps  10  are continuously and automatically capped at high speed on the syringes. The capping is, therefore, required to be easy. On the other hand, the syringes  20  with the caps  10  applied thereon are conveyed on and along a production line at a pharmaceutical company or the like with the caps  10  directed downwards, and a drug solution is continuously filled in the syringes  20 . It is, therefore, not permissible for these caps  10  to fall off, for example, during the filling of the drug solution. As described above, the mutually-contradictory performances of easy capping and falling-off prevention are required for the caps  10 . 
         [0009]    For such mutually-contradictory requirements as described above, it is proposed in Patent Document 1 to arrange a helical ridge on the outer wall of the cylindrical leg portion  2  of the cap and to bring the helical ridge into engagement with a helical ridge  9  formed on the inner wall of the female luer-lock fitting  7 . The above-described proposed cap can be surely capped by manually bringing it into threaded engagement with the female luer-lock fitting, and upon filling a drug solution, the possibility of falling-off of the cap is low. 
       Patent Document 1: JP-A-2002-153539 
     SUMMARY 
       [0010]    When performing automated, high-speed capping of the caps, however, it is difficult to bring the helical ridge on each cap into threaded engagement with the helical ridge  9  on the corresponding female luer-lock fitting. The group of syringes so capped, therefore, includes those capped incompletely in a state that the helical ridges are not in mutual threaded engagement, thereby developing a problem that upon filling a drug solution into the syringes or on a conveyance line before or after the filing, the caps may fall off from the syringes and the drug solution may hence leak out. 
         [0011]    An aspect of the disclosed embodiments is, therefore, to provide a nozzle cap for a pre-filled syringe, which can be surely and automatically capped at high speed on a syringe having a female luer-lock fitting without occurrence of it falling-off, for example, upon filling a drug solution. 
         [0012]    The above-described aspect as well as other aspects and benefits can be achieved by the disclosed embodiments as described hereinafter. Described specifically, the disclosed embodiments provide an injection nozzle cap ( 10 ) which can be fittedly inserted in a space between an injection nozzle of a syringe having a cylindrical, female luer-lock fitting and the female luer-lock fitting, whereby the injection nozzle cap ( 10 ) comprises a base portion ( 1 ) and a cylindrical leg portion ( 2 ) extending downwardly from the base portion ( 1 ), and the cylindrical leg portion ( 2 ) is provided on an outer wall thereof with a substantially annular, bulged portion and/or a ring. 
         [0013]    In the above-described cap ( 10 ) according to the disclosed embodiments, an inner diameter (β) of a distal end portion of the cylindrical leg portion ( 2 ) may be formed greater than an inner diameter (α) of a boundary portion between the cylindrical leg portion ( 2 ) and the base portion ( 1 ); and the cylindrical leg portion ( 2 ) may be coated on at least an inner surface and/or outer surface thereof with a fluorinated resin film. 
         [0014]    According to the disclosed embodiments, there can be provided a nozzle cap for a pre-filled syringe, which can be surely and automatically capped at high speed on a syringe having a female luer-lock fitting without occurrence of it falling-off, for example, upon filling a drug solution. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  shows a partial side and partial cross-sectional view illustrating a cap according to the disclosed embodiments; 
           [0016]      FIG. 2  shows a plan view of the cap according to the disclosed embodiments; 
           [0017]      FIG. 3  shows a view illustrating the manner of use of the cap according to the disclosed embodiments; and 
           [0018]      FIG. 4  shows a view illustrating the relation between a syringe and a cap. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0019]    The disclosed embodiments will next be described with reference to the drawings.  FIG. 1  is a view illustrating a cap according to the disclosed subject matter, in which the left half is a side view and the right half is a cross-sectional view.  FIG. 2  is a plan view of the cap of  FIG. 1 . As depicted in  FIG. 1  and  FIG. 2 , the cap  10  according to the disclosed embodiments is comprised of a rubber-made, solid, circular or polygonal cylindrical, rubber-made base portion  1  and a rubber-made, cylindrical leg portion (which may hereinafter be simply called “leg portion”)  2  formed integrally with and extending downwardly from the base portion  1 . The base portion  1  is formed solid to provide the entire cap  10  with a certain degree of rigidness. 
         [0020]    The base portion  1  depicted in  FIG. 1  and  FIG. 2  is provided on a top portion thereof with some small convexities  3 . These convexities  3  are intended to prevent plural caps  10  from sticking each other at the time of washing, drying or the like in the course of their production. However, these convexities constitute an exemplary embodiment. The number of such convexities is not limited to four, and the arrangement of at least one convexity can be used in an exemplary device. On an outer periphery of the base portion  1 , four recessed parts  4  are also formed. As illustrated in  FIG. 3 , these recessed parts  4  are arranged to permit easy detachment of the cap  10  from the syringe  20  by a thumb upon using the syringe  20 . These recessed parts  4  also constitute another exemplary embodiment. The number of such recessed parts is not limited to four, and the arrangement of a plurality of recessed parts is possible. 
         [0021]    The leg portion  2 , which constitutes the cap  10  according to the presently disclosed subject matter, is formed in the shape of a cylinder in continuation with a lower wall of the base portion  1  such that the cylinder is open at a distal end thereof. A lower wall of the base portion  1 , said lower wall  5  extending to an outer upper part of the outer periphery of the leg portion  2 , is located at a position where the base portion  1  is in contact with a top wall of a female luer-lock fitting  7  as shown in  FIG. 4 , and an outer wall of the leg portion  2 , said outer wall downwardly extending from the lower wall  5 , is formed in a shape that the outer wall gently bulges out in the form of a circular arc the peak of which is located at substantially the middle between the top and bottom of the outer wall. 
         [0022]    The degree of the above-described bulge may be in the range of h/L=0.5/6.0 to 1.0/6.0, possibly h/L=0.6/6.0 to 0.9/6.0 in which L represents the length of a line a-b (a: a start point at the position of connection between the base portion  1  and the leg portion  2 ; b: an end point at the distal end of the leg portion  2 ) and h represents the height from the line a-b to the ridge of the bulge. An h/L value greater than the above-described range may not be useful for the automated capping of the cap  10  on the syringe  20 , while an h/L value smaller than the above-described range may lead to falling-off of the cap  10  from the syringe  20 , for example, upon filling a drug solution. 
         [0023]    It is to be noted that instead of the above-described bulge shape, the bulged portion may also be in the shape of a ring formed on only a part of the leg portion in the presently disclosed subject matter. According to one embodiment, the leg portion is not provided with any helical ridge threadedly engageable with the helical ridge  9  formed on the female luer-lock fitting  7  of the syringe  20  but is provided with the bulged portion or ring which does not threadedly engage the helical ridge  9 . Owing to such a construction, it is possible to achieve certain aspects of the presently disclosed subject matter that is to automatically cap the cap  10  at high speed on the syringe  20  and to prevent the cap  10  from falling off from the syringe. 
         [0024]    Further, two or more bulged portions or rings can be configured in the disclosed embodiments. However, the greater the number of bulged portions or rings, the higher the capping resistance of the cap  10 , resulting in the observation of a phenomenon called “a cap lift” that a clearance is formed between the lower wall  5  of the base portion  1  of the cap  10  and the top wall of the female luer-lock fitting  7  after the capping. Accordingly, the number of bulged portion(s) or ring(s) can be 1 or 2. 
         [0025]    The position of the ridge of the bulged portion or ring may be around the middle of the outer wall of the leg portion  2  in many instances. This position can be selectively set as desired depending on the shape of the cap  10  and the dimensions and shapes of the female luer-lock fitting  7  and nozzle  8  of the syringe  20 . For example, the setting of the position of the ridge of the bulged portion or ring on a side close to the base portion  1  is highly effective for the inhibition of a lift of the cap, while the setting of the ridge on the side of the distal end of the leg portion  2  is highly effective for the reduction of the capping resistance of the cap. 
         [0026]    It is to be noted that the ridge of the bulged portion or ring may be formed over the entire circumference of the leg portion  2 . For air bleeding or the like upon capping, however, the ridge may be formed intermittently. In such a case, the parts at which no ridge is formed (interrupted parts) may account for less than 40%, more particularly for less than 20% of the entire circumference of the bulged portion or ring. The bulged portion or ring may be formed such that it extends out in a direction perpendicular to the capping direction of the cap  10 . Such construction is effective in stabilizing the state of engagement between the helical ridge  9  of the female luer-lock fitting  7  and the bulged portion or ring of the cap  10  when the cap  10  is capped on the syringe  20 , and hence in reducing a variation in the capping resistance or falling-off resistance of the cap  10 . 
         [0027]    In the disclosed embodiments, an open, distal end portion of the cylindrical leg portion  2  may be formed with an inner diameter (β) greater than the inner diameter (α) of a boundary portion between the cylindrical leg portion  2  and the base portion  1 . In other words, the leg portion  2  may be in a shape that it is somewhat wider at its opening than at the boundary portion. As the leg portion  2  somewhat flares out at the opening, the fitting insertion of the cap  10  into the syringe  20  causes the opening to shrink so that upon filling a drug solution, the falling-off of the cap  10  from the syringe  20  can be prevented owing to the resilience of the leg portion  2  that it tries to recover its original shape. 
         [0028]    The degree of the flare of the opening differs depending on the length of the leg portion  2 , the friction resistance between the material of the cap  10  and that of the syringe  20 , and the like. However, the opening may have a flare a little smaller than 6/100 which is a taper of the nozzle  8 . Despite the somewhat flared configuration of the opening of the leg portion  2  as described above, no problem arises upon capping because the outer wall of the distal end of the leg  2  is formed with roundness (a curved surface). 
         [0029]    Further, the leg portion  2  is fittedly inserted in the space between the nozzle  8  of the syringe  20  and the female luer-lock fitting  7 , an internal space of the cylindrical leg portion  2  is configured to surround the nozzle  8 , and a downward protuberance  6  is formed on a ceiling of an inside surface of the cylinder leg portion  2  (namely, at the boundary with the base portion  1 ). This protuberance  6  is formed such that it just closes up a bore of the nozzle  8  when the cap  10  is fittedly inserted in the space between the nozzle  8  of the syringe  20  and the female luer-lock fitting  7 . 
         [0030]    The inner diameter of the leg portion  2  of the cap  10  according to the presently disclosed subject matter is slightly smaller than the outer diameter of the nozzle  8  of the syringe  20 . When the nozzle  8  of the syringe  20  is inserted into the leg portion  2 , the leg portion  2  is caused to flare out so that sealing performance for the nozzle  8  is maintained. Further, the outer wall of the leg portion  2  comes into contact under pressure with a cylindrical inner wall of the female luer-lock fitting  7 . This pressure contact also takes part in the maintenance of the sealing performance of the cap  10 , and moreover, is effective in preventing the cap  10  from falling off. 
         [0031]    The cap  10  according to the disclosed embodiments can most prominently bring about advantageous effects when the leg portion  2  is coated on at least its outer surface, possibly on its entire surfaces with a fluorinated resin film of approx. 10 to 200 μm thickness (not shown) concurrently with the molding of the cap  10 . In general, the inner surface and outer surface of the leg portion  2  may come into contact with a drug solution filled in the syringe  20 , so that the fluorinated resin film is laminated to eliminate the possibility of mixing of toxic substances into the drug solution from the rubber-made cap  10  by its contact with the drug solution. 
         [0032]    When the fluorinated resin film is laminated on the surface of the leg portion  2 , its lubricity facilitates the automated capping of the cap  10  but renders the cap  10  prone to fall off from the syringe  20  upon filling the drug solution. Owing to the above-described construction, the disclosed embodiments can make the cap  10  free of such a problem upon automated capping and also resistant to falling-off upon filling the drug solution even when the cap  10  is provided with the fluorinated resin film laminated on the leg portion  2 . 
         [0033]    The dimensions of the cap  10  according to the disclosed embodiments varies depending on the dimensions of the syringe  20 . For example, referring to  FIG. 1 , the height H of the base portion  1  can be 8 to 20 mm or so (15 mm in the illustrated embodiment), the width (diameter) W 1  of the base portion  1  can be 8 to 13 mm or so (9.75 mm in the illustrated embodiment), the height and diameter of each convexity  3  arranged on the base portion  1  can be 0.2 to 0.3 mm or so and 0.7 to 1.3 mm or so, respectively (0.25 mm and 1.0 mm, respectively, in the illustrated embodiment), and the depth and size of each recessed part  4  arranged on the base portion  1  can be 0.4 to 0.8 mm or so and 3 to 5×5 to 7 mm or so, respectively (0.6 mm and 4×6.5 mm, respectively, in the illustrated embodiment). 
         [0034]    On the other hand, the length L of the leg portion  2  can be 3 to 10 mm or so (6 mm in the illustrated embodiment), the outer diameter W 2  of the leg portion  2  can be 10 to 13 mm (11.2 mm in the illustrated embodiment), the depth of the internal space (nozzle-receiving portion) of the leg portion  2  can be 7 to 10 mm or so (8.5 mm in the illustrated embodiment), the inner diameters α and β in the internal space of the leg portion  2  can be 3.0 to 5.0 mm or so and 3.5 to 6.0 mm, respectively (3.7 mm and 4.1 mm, respectively, in the illustrated embodiment), the h in the leg portion  2  can be 0.5 to 1.0 mm or the like (0.8 mm in the illustrated embodiment), and the thickness of the unillustrated fluorinated resin film coated on the entirety of the leg portion  2  can be 10 to 200 μm (50 μm in the illustrated embodiment). It is to be noted that the cap  10  is molded in its entirety of chlorinated butyl rubber. 
         [0035]    Except for the possession of such construction as described above, the cap  10  according to the disclosed embodiments can be produced in a similar manner as the caps for the conventional pre-filled syringes. The rubber material for use in the production of the cap according to the presently disclosed subject matter may be butyl rubber or chlorinated butyl rubber. Including additives, those employed in the production of conventional caps and also of conventional rubber plugs or closures for drugs and medical care are all usable, and no particular limitation is imposed thereon. To prevent the surfaces of the leg portion of the cap and the content of the syringe from coming into direct contact with each other, the surfaces can be coated with high molecular weight polyethylene films or films of a resin such as a fluorinated resin similar to the conventional caps and the conventional rubber plugs or closures for drugs and medical care. 
         [0036]    Likewise, the surfaces of the base portion  1  can also be coated with such films. These films are not applied under the premise of the contact of the surfaces with a drug solution, but are coated to overcome the tackiness which the rubber possesses. The films for this purpose can be those of a general-purpose resin such as, for example, polyethylene or polypropylene. 
         [0037]    According to the disclosed embodiments as described above, it is possible to provide a cap for a pre-filled syringe, which can be surely and automatically capped on a syringe having a female luer-lock fitting and which does not fall off upon filling a drug solution. 
       LEGEND 
       [0000]    
       
           1 : Base portion 
           2 : Leg portion 
           3 : Convexities 
           4 : Recessed parts 
           5 : Lower wall 
           6 : Protuberance 
           7 : Female luer-lock fitting 
           8 : Injection nozzle 
           9 : Helical ridge 
           10 : Cap 
           20 : Syringe