Pre-Filled Disposable Injection Device

Abstract

The present invention relates to a pre-filled disposable injection device and a needle cannula in combination. The prefilled disposable injection device ( 1 ) is made from a housing ( 2 ) containing a non-exchangeable cartridge ( 10 ) for storing a liquid drug sufficient for a number of injections. The proximal end of the pre-filled injection device ( 1 ) carries the dose setting button ( 3 ) and the distal end carries the needle cannula ( 20 ) having a lumen ( 21 ) through which the settable dose is expelled. The distal end ( 23 ) of the needle cannula ( 20 ) is covered by a telescopic needle covering shield ( 30 ) which shield ( 30 ) can operate between a first position covering the tip ( 24 ) of the needle cannula ( 20 ) and a second retracted position allowing an injection to be performed. The shield ( 30 ) carries a cleaner ( 50 ) which cleans at least the tip ( 24 ) of the needle cannula ( 20 ) between successive injections such that the prefilled injection device can be used without changing the needle cannula ( 20 ) during its life cycle.

1 . A pre-filled disposable injection device having a needle cannula permanently mounted thereon, comprising:
 a housing containing a non-exchangeable cartridge for storing a liquid drug sufficient for a number of injections, and which cartridge is permanently embedded in the injection device,   a settable dose setting mechanism having a dose setting button whereby a user can set a size of a dose to be injected,   the needle cannula, which is maintained attached to the injection device between injections and permanently mounted to the housing of the injection device and follows a life cycle of the pre-filled injection device, comprising a front part having a tip for penetrating skin of the user, a back part for penetrating into the cartridge, and a lumen usable for passage of the liquid drug in the non-exchangeable cartridge through an initial injection followed by a successive number of injections sufficient to deplete the liquid drug in the cartridge,   a telescopic needle covering shield distally carrying a cleaner comprising a hollow chamber containing a liquid cleaning solvent, and which shield can operate between a first position and a second position;
 the first position being a position in which the telescopic shield is in an extended position covering the tip of the front part of the needle cannula, 
 the second position being a position in which the shield is retracted such that at least the tip of the front part of the needle cannula is exposed to perform an injection, and 
   
       wherein at least the lumen of the needle cannula is preserved in a sterile condition prior to the initial injection and wherein a resilient structure automatically returns the shield to the first position following both the initial injection and any of the successive injections, and in which the first position at least the tip of the front part of the needle cannula is contained within the cleaner to thereby prevent clogging of the lumen of the needle cannula, 
       wherein the shield allows for a plurality of doses where the shield operates between the first position and the second position a plurality of times. 
     
     
         2 . A pre-filled disposable injection device according to  claim 1 , which further comprises a valve which is configured to prevent flow passage through the lumen of the needle cannula when the needle shield is in its first position. 
     
     
         3 . A pre-filled disposable injection device according to  claim 1 , wherein the back part of the needle cannula is movable relatively to the cartridge between
 a non-flow position in which the back part of the needle cannula is disconnected from the cartridge such that the liquid drug flow through the lumen is interrupted, and   a flow position in which the back part of the needle cannula is connected to the cartridge such that the liquid drug can flow freely through the lumen, wherein   
       the back part of the needle cannula is in the non-flow position when the shield is in its first position and the back part of the needle cannula is in the flow position when the shield is in its second position. 
     
     
         4 . A pre-filled disposable injection device according to  claim 1 , wherein the back part of the needle cannula is movable relatively to the cartridge between
 a non-flow position in which the back part of the needle cannula is disconnected from the cartridge such that the liquid drug flow through the lumen is interrupted, and   a flow position in which the back part of the needle cannula is connected to the cartridge such that the liquid drug can flow through the lumen, wherein   
       the back part of the needle cannula is moved from the non-flow position to the flow position when the shield is moved from its first position to its second position during the initial injection and wherein the back part remains in the flow position when the shield moves back to its first position. 
     
     
         5 . A pre-filled disposable injection device according to  claim 3 , wherein the needle cannula is secured to an axial movable hub. 
     
     
         6 . A pre-filled disposable injection device according to  claim 1 , wherein the shield is locked by a locking mechanism preventing the shield from moving from the first position to the second retracted position unless a dose has been dialled.