Abstract:
A tamper evident protector cap for a pre-filled syringe or cartridge barrel stoppered by an elastomeric closure. The protector cap securely retains the elastomeric closure during in-line processing, handling and shipment. The protector cap includes frangible brackets which on tampering break away from the protector cap evidencing that product integrity might have been jeopardized and the product should not be used.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a tamper evident protector cap for a pre-filled syringe barrel. More particularly, the invention relates to a cap for a syringe barrel containing a liquid medication therein for securely holding a closure in the tapered tip of the syringe barrel and serving as a tamper evident indicator. 
     2. Reported Developments 
     Pre-filled syringe barrels or cartridges containing injectable solutions therein are stoppered by elastomeric closures, such as soft rubber stoppers at the distal, tapered end thereof, while the proximal end of the barrels are closed by slidable plungers. The pre-filled syringe barrels or cartridges are sterilized, such as by autoclaving, and packaged ready for use. 
     It has been observed that during in-line processing, handling, and sterilizing the pre-filled barrels some elastomeric closures were missing from the tips of the barrels resulting in rejects. Also, during shipment of the finished product and handling by healthcare professionals some untipped barrels were observed which necessitated the discarding of batches containing failed samples. For product integrity a corrective measure was indicated to prevent the elastomeric closure from becoming dislodged from the tip of the barrel. 
     More importantly, it has also been recognized that untipped barrels (whether the damage occurred during shipment or handling) attracts the suspicion that the product was tampered with. Such possible tampering is a concern for both the FDA and the manufacturers who are required to insure safety, efficacy and product integrity. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention a protective cap is provided for a syringe or cartridge barrel. The syringe or cartridge barrel, comprising a cylindrical chamber containing a pharmaceutical or biological liquid in the form of an injectable solution, terminates in a tapered tip having a bore therethrough. The tapered tip is equipped with a female luer connector barrel to which a male luer connector or an injection needle may be attached. The bore in the tapered tip is stoppered by an elastomeric closure, such as a soft rubber plug. The protective cap covering the tapered tip comprises a cylindrical top portion; and a bottom skirt portion having: two semi-circular walls facing each other and spaced 180° from each other; and two frangible brackets facing each other and spaced 180° from each other, each of the brackets terminating in a horizontal leg adapted to engage the female luer connector barrel. The two semi-circular walls provide strength and rigidity to the protector cap, while the brackets are designed to disengage the female luer connector barrel thereby allowing easy removal of the protector cap. At the point of disengagement the brackets break away from the skirt portion of the protector cap indicating that the protector cap has been removed from the tip of the syringe or cartridge barrel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a syringe barrel equipped with the tamper evident protector cap of the present invention; 
     FIG. 2 is a perspective view of the tamper evident protector cap removed from the syringe barrel; 
     FIG. 3 is a side elevational view of the tamper evident protector cap taken along the line  3 — 3  of FIG. 2; 
     FIG. 4 is another side elevational view of the tamper evident protector cap turned 90° from that shown in FIG. 3; 
     FIG. 5 is a bottom plan view of the tamper evident protector cap; and 
     FIG. 6 is a top plan view thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a typical syringe or cartridge barrel generally designated by the numeral  10 , made of glass or a polymeric material having an inner surface  12  defining a cylindrical chamber  13  for retaining a pharmaceutical or biological liquid therein. The barrel has a distal end  14  terminating in a tapered tip  15  having a bore therethrough to which an injection needle or a luer connector with a tubing conduit can be attached, and a proximal end  16  for receiving a plunger  18  which retains the pharmaceutical or biological liquid in the barrel and which, upon use, expels the pharmaceutical or biological liquid from the barrel when an external pressure is exerted on the plunger. The tapered tip  15  having a bore therein is stoppered by a resilient closure  20 , such as an elastomeric closure or a soft rubber stopper, for hermetically sealing the distal end of the barrel. At its proximal end  16  the barrel is equipped with an integral flange  22  to facilitate the handling of the barrel. When the pharmaceutical or biological liquid is an injectable solution, the barrel along with its content is sterilized, preferably by autoclave. After sterilization the barrel is packaged and stored ready for use when needed. Delivery of the injectable solution is accomplished by removing the resilient closure from the tapered tip and attaching an injection needed or a luer connector onto the tapered tip of the barrel. 
     Surrounding the tapered tip  15 , a female luer connector barrel  17  is provided for attachment of a male luer connector or an injection needle thereto. The luer connector barrel comprises an open distal end  19 , and a closed proximal end  21 . 
     To prevent the risk of fall out of the resilient closure from the tip of the barrel and to insure product integrity against tampering, a protector cap, generally designated by the numeral  24 , covers the tip  15  of barrel  10  and securely holds resilient closure  20  in the barrel. 
     Reference is now made to FIGS. 2-6 wherein: FIG. 2 is a perspective view of the protector cap; FIG. 3 is a side elevational view of the protector cap; FIG. 4 is another side elevational view of the protector cap turned 90° from that shown in FIG. 3; and FIG.  5  and FIG. 6 are bottom plan and top plan view, respectively, of the protector cap. Protector cap  24  comprises: a cylindrical top portion  26  terminating in a circular surface  27 , and a bottom somewhat larger cylindrical skirt portion, generally designated by the numeral  28 . Skirt portion comprises: a distal top portion  30  extending into top cylindrical portion  26 ; two semi-circular walls  32  and  32 ′ facing each other and spaced 180° from each other; two frangiblc brackets  34  and  34 ′ facing each other and spaced 180° from each other, each of the frangible brackets terminating in a horizontal leg  36  and  36 ′. 
     The protector cap  24  is made of a polymeric material including: polyolefins such as polyethylene and polypropylene; polystyrene, polycarbonate, polymethylpentene, cyclic olefin copolymers, acrylic polymers and methacrylic polymers. 
     As shown in FIG. 1, protector cap  24  encloses the resilient closure  20  and locks over the luer connector barrel  17 . The two frangible brackets  34  and  34 ′ having horizontal legs  36  and  36 ′ engage the proximal end  21  of the luer connector barrel  17  when the protector cap  24  is placed on the tapered tip  15  of the syringe or cartridge barrel  10 . The positioning of the protector cap onto the tip of the barrel is accomplished by snapping the protector cap downward so that the horizontal legs  36  and  36 ′ lock over the luer connector barrel  17 . Once the protector cap is snapped on the luer connector barrel, it will securely hold the resilient closure in place. 
     FIGS. 3 and 4 show side elevational views of the protector cap subsequent to its removal from the tip of the barrel. Upon removal of the protector cap by a twisting or lifting motion the frangible brackets  34  and  34 ′ crack and horizontal legs  36  and  36 ′ are released from holding onto the proximal end of the luer connector barrel  21 . If the protector cap is tampered with, the healthcare professional will readily observe the separated brackets not holding onto the tapered tip of the syringe or cartridge barrel. The product then will not be used and will be returned to the manufacturer with complaints. 
     The tamper evident protector cap may also be secured to the tip of the syringe barrel by a bonding adhesive or a solvent. It is also contemplated that the resilient closure or plug may be manufactured integral with the tamper evident protector cap wherein the resilient closure is to be made of a thermoplastic elastomer allowing the use of a two shot mold manufacturing. 
     PARTS LIST 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 Syringe or cartridge barrel 
                 10 
               
               
                 Inner surface of syringe or cartridge barrel 
                 12 
               
               
                 Cylindrical chamber defined by the inner surface 
                 13 
               
               
                 Distal end of barrel 
                 14 
               
               
                 Tapered tip of barrel 
                 15 
               
               
                 Proximal end of barrel 
                 16 
               
               
                 Luer connector barrel 
                 17 
               
               
                 Plunger 
                 18 
               
               
                 Open distal end of luer connector barrel 
                 19 
               
               
                 Resilient closure 
                 20 
               
               
                 Closed proximal end of luer connector barrel 
                 21 
               
               
                 Flange of the barrel 
                 22 
               
               
                 Protector cap, generally designated 
                 24 
               
               
                 Top cylindrical portion of protector cap 
                 26 
               
               
                 Flat circular surface of protector cap 
                 27 
               
               
                 Bottom cylindrical skirt portion of protector cap, generally 
                 28 
               
               
                 designated 
               
               
                 Distal top portion of the skirt portion 
                 30 
               
               
                 Two semi-circular walls of skirt portion 
                 32 &amp; 32′ 
               
               
                 Two frangible brackets 
                 34 &amp; 34′ 
               
               
                 Two horizontal legs on the frangible brackets 
                 36 &amp; 36′ 
               
               
                   
               
             
          
         
       
     
     Various modifications of the present invention disclosed will become apparent. This invention is intended to include such modifications to be limited only by the scope of the claims.