Needle assembly for a prefilled syringe system

Abstract

A needle assembly ( 10; 210 ) for a prefilled injection syringe is described. A needle holder ( 12; 212 ) has a needle ( 14; 214 ) secured to it and is adapted to be secured to a syringe barrel of the injection syringe. A needle sheath ( 16; 216 ) has a distal end forming a releasable sterile seal with the needle holder ( 12; 212 ), and surrounds and shields the needle ( 14; 214 ). A needle seal ( 18; 218 ) surmounts the needle tip and is arranged at least in part in the proximal end of the needle sheath ( 16; 216 ) and closed off by a closure element ( 20; 220 ). A closure connection between the closure element ( 20; 220 ) and the needle sheath ( 16; 216 ) is configured as a non-releasable and sterile barrier ( 54; 254 ) produced by means of bonding or welding.

1 . A needle assembly ( 10 ;  210 ) for a prefilled injection syringe, comprising:
 a needle holder ( 12 ;  212 ) adapted to be secured to a syringe barrel of the injection syringe and a needle ( 14 ;  214 ) secured to the needle holder ( 12 ;  212 );   a needle sheath ( 16 ;  216 ), releasably connected at its distal end to the needle holder ( 12 ;  212 ) to form a sterile seal, and surrounding and shielding the needle ( 14 ;  214 );   a needle seal ( 18 ;  218 ) located on the needle tip and arranged at least in part in the proximal end of the needle sheath ( 16 ;  216 ); and   a closure element ( 20 ;  220 ) that closes off the proximal end of the needle seal;   characterized by:   a closure connection between the closure element ( 20 ;  220 ) and the needle sheath ( 16 ;  216 ), configured as a non-releasable and sterile barrier ( 54 ;  254 ) produced by means of bonding or welding.   
   
   
       2 . The needle assembly as set forth in  claim 1 , characterized in that said sterile barrier ( 54 ;  254 ) is produced by ultrasonic welding. 
   
   
       3 . The needle assembly as set forth in  claim 1 , characterized in that said sterile barrier ( 54 ;  254 ) is produced by laser welding. 
   
   
       4 . The needle assembly as set forth in  claim 1 , characterized by the use of non-toxic acrylic-based adhesives for curing by means of UV light or at room temperature for producing said sterile barrier ( 54 ;  254 ) by means of a bonding technique. 
   
   
       5 . The needle assembly as set forth in any of the  claims 1  to  4 , characterized in that said closure element ( 20 ;  220 ) is a cap ( 56 ;  256 ) with a cylindrical shell ( 60 ;  260 ), and said needle sheath ( 16 ;  216 ) is a tubular member ( 32 ;  232 ), the proximal end of which is provided with a ring flange ( 34 ;  234 ), the distal rim ( 62 ;  262 ) of said cap shell ( 60 ;  260 ) connecting said ring flange ( 34 ;  234 ) of said needle sheath ( 16 ;  216 ) in forming a sterile barrier ( 54 ;  254 ). 
   
   
       6 . The needle assembly as set forth in  claim 5 , characterized in that said ring flange ( 34 :  234 ) of said needle sheath ( 16 ;  216 ) is provided at the outer edge of its proximal side with an annular face ( 36 ;  236 ) for securing said distal rim ( 62 ;  262 ) of said cap shell ( 60 ,  260 ). 
   
   
       7 . The needle assembly as set forth in any of the preceding claims, characterized by:
 a supporting collar ( 38 ;  238 ) jutting forwards from the proximal side of said ring flange ( 34 ,  234 ) of said needle sheath ( 16 ;  216 ) radially within said outer annular securing face ( 36 :  236 ) for said closure element ( 20 ;  220 ),   a flange-type extension ( 48 ;  248 ) of the upper end of said needle seal ( 18 ;  218 ) with which said needle seal ( 18 ;  218 ) is supported by said supporting collar ( 38 ;  238 ) of said needle sheath ( 16 ;  216 ) thereof, and   the distal side ( 70 ) of said closure element ( 20 ;  220 ) contacting a proximal end of said needle seal ( 18 ;  218 ).   
   
   
       8 . The needle assembly as set forth in  claim 7 , characterized in that the proximal end of said flange-type extension ( 48 ;  248 ) of said needle seal ( 18 ;  218 ) is provided with a ring collar ( 50 ;  250 ) contacting the distal side ( 70 ;  270 ) of said header plate ( 58 ;  258 ) of said closure element ( 20 ;  220 ) 
   
   
       9 . The needle assembly as set forth in  claim 7 , characterized in that said ring flange ( 34 ) of said needle sheath ( 16 ) and said supporting collar ( 38 ) each comprise at said ring flange ( 34 ) of said needle sheath ( 16 ;  216 ) a cylindrical inner surface area ( 46 ) whose bore corresponds to the bore of said cylindrical inner surface area of said needle sheath ( 16 ). 
   
   
       10 . The needle assembly as set forth in  claim 7 , characterized in that said inner surface area ( 246 ) of said supporting collar ( 238 ) of said needle sheath ( 216 ) is flared conically proximally and that said flange-type extension ( 248 ) of said needle seal ( 218 ) has a circumferential surface area which at least over a portion ( 249 ) of its distal end matches the shape of said conical inner surface area ( 246 ) of said supporting collar ( 238 ) and is supported by this conical partial portion ( 248 ) at said inner surface area ( 246 ) of said supporting collar ( 238 ). 
   
   
       11 . The needle assembly as set forth in one or more of the preceding claims, characterized in that the distal end of said needle seal ( 18 ) receiving said needle tip contains a central opening ( 42 ) for said needle ( 14 ). 
   
   
       12 . The needle assembly as set forth in one or more of the preceding claims, characterized in that a portion ( 40 ;  240 ) of said needle seal ( 18 ;  218 ) arranged distally of said flange-type extension ( 48 ;  248 ) extends into said supporting collar ( 38 ;  238 ) into the proximal end of said needle sheath ( 16 ;  216 ), and comprises a diameter substantially equal to that of the inner space of said needle sheath ( 16 ;  216 ). 
   
   
       13 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle sheath ( 16 ;  216 ) is integrally connected at its distal end by a designed frangible connection ( 52 ;  252 ) to a proximal portion of said needle holder. 
   
   
       14 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said closure element ( 20 ;  220 ) and said needle sheath ( 16 ;  216 ) are made of an amorphous or partly crystalline thermoplastic, such as polypropylene or polythene. 
   
   
       15 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle seal ( 18 ;  218 ) is made of a pharmaceutical rubber or a thermoplastic elastomer. 
   
   
       16 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle ( 14 ;  214 ) is made of a stainless steel. 
   
   
       17 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle ( 14 ;  214 ) is fixedly bonded in said needle holder ( 12 ;  212 ) coaxially to said needle sheath ( 16 ;  216 ). 
   
   
       18 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle ( 14 ;  214 ) is fixedly connected to said needle holder ( 12 ;  212 ) by a plastics potting. 
   
   
       19 . The needle assembly as set forth in one or more of the preceding claims, characterized in that said needle holder ( 12 ;  212 ) is made of a thermoplastic such as polycarbonate, polypropylene or polyamide. 
   
   
       20 . A method of manufacturing a needle assembly ( 10 ;  210 ) for a prefilled injection syringe, comprising:
 securing a needle to a needle holder ( 12 ;  212 ) that is adapted to be secured to a syringe barrel of the injection syringe;   releasably connecting the distal end of a needle sheath ( 16 ;  216 ) to the needle holder ( 12 ;  212 ) to form a sterile seal, and to surround and shield the needle ( 14 ;  214 );   locating a needle seal ( 18 ;  218 ) on the needle tip and at least in part in the proximal end of the needle sheath ( 16 ;  216 ); and   closing off the proximal end of the needle seal with a closure element ( 20 ;  220 ); and   characterized by:   forming a closure connection between the closure element ( 20 ;  220 ) and the needle sheath ( 16 ;  216 ), configured as a non-releasable and sterile barrier ( 54 ;  254 ), by means of bonding or welding.   
   
   
       21 . The method of  claim 20 , in which:
 a first subassembly of the needle seal ( 18 ;  218 ), closure element ( 20 ;  220 ) and needle sheath ( 16 ;  216 ) is formed, in which the needle seal ( 18 ;  218 ) is arranged at least in part in the proximal end of the needle sheath ( 16 ;  216 ) and the closure element ( 20 ;  220 ) closes off the proximal end of the needle seal;   a second subassembly is formed by securing the needle ( 14 ;  214 ) to the needle holder ( 12 ;  212 ); and   the first and second subassemblies are offered up to one another so that the needle sheath. ( 16 ;  216 ) releasably connects at its distal end to the needle holder ( 12 ;  212 ) to form a sterile seal, and surrounds and shields the needle ( 14 ;  214 ), and the needle seal ( 18 ;  218 ) locates on the needle tip.   
   
   
       22 . A method according to  claim 20 , in which:
 a first subassembly is formed by securing the needle ( 14 ;  214 ) to the needle holder ( 12 ;  212 );   a second subassembly is formed by inserting the first subassembly into the needle sheath ( 16 ;  216 );   a third subassembly is formed by mounting the needle seal ( 18 ,  218 ) onto needle tip and needle sheath ( 16 ;  216 ) of the second subassembly; and   the needle assembly is completed by forming the closure connection between the closure element ( 20 ;  220 ) and the needle sheath ( 16 ;  216 ) of the third subassembly.