Patent ID: 7445612

Claim:
An injection device for injecting a composition into a subject, the device comprising: a hollow housing ( 10 ) having a proximal end and a distal end, said distal end being configured to contain a liquid ( 20 B) and a solid drug composition ( 20 A) separate from each other, wherein said liquid ( 20 B) and said solid drug composition ( 20 A) are combined in said housing ( 10 ) prior to injection to form a composition ( 20 ) for injection into a subject; a hollow needle ( 12 ) affixed to the distal end of the housing ( 10 ), said needle ( 12 ) having a distal end extending outside of the housing ( 10 ) and having a proximal end extending longitudinally within said housing ( 10 ); a plunger ( 29 ) comprising a proximal end and a distal end, said plunger ( 29 ) arranged to slide within the proximal end of the housing ( 10 ); a septum plunger ( 16 ) slidably arranged within the housing ( 10 ) between the plunger ( 29 ) and the distal end of the housing ( 10 ), said septum plunger ( 16 ) being configured to isolate the composition ( 20 ) between the septum plunger ( 16 ) and the distal end of the plunger ( 29 ); a hollow sleeve ( 22 ) slidably connected to the distal end of the housing ( 10 ) and arranged to cover the needle ( 12 ) prior to injection, to retract into the housing ( 10 ) during injection and to cover the needle ( 12 ) after the injection upon contact with said septum plunger ( 16 ) as said septum plunger ( 16 ) is displaced by said plunger ( 29 ) towards the distal end ( 14 b ) of said housing ( 10 ); and wherein the device ( 1 ) is designed such that when the sleeve ( 22 ) is pressed against the subject ( 34 ), the sleeve ( 22 ) retracts into the housing ( 10 ) thereby allowing the needle ( 12 ) to penetrate into the subject ( 34 ), and when the plunger ( 29 ) is pushed into the housing ( 10 ), the proximal end of the needle ( 12 ) pierces the septum plunger ( 16 ) thereby exposing the proximal end of the needle ( 12 ) to the previously isolated composition ( 20 ) and the composition ( 20 ) is pushed from the housing ( 10 ) into and through the needle ( 12 ) and into the subject ( 34 ).