Patent ID: 6648859
Filing Date: 2003-11-18
Classification: A61M

Abstract:
A medication delivery pen comprising:a drug cartridge including: a generally tubular barrel having a distal end and an open proximal end, with a chamber defined by a tubular wall of said barrel extending between said distal end and said proximal end; sealing means located on with said distal end of said tubular barrel for sealing said distal end of said tubular barrel; and, plunger means located on with said open proximal end of said tubular barrel in sliding fluid-tight engagement with said tubular wall of said barrel for selective engagement with an advancing member so that distally directed forces on said plunger urge a medication pre-filled in said chamber from said drug cartridge; a pen body assembly adapted to be releasably interconnected to said drug cartridge, said pen body having proximal and distal ends; and mating means for releasably interconnecting said drug cartridge with said pen body assembly, said mating means including at least one bayonet thread having a substantially U-shaped configuration with a closed bottom and at least one projecting tab, said bayonet thread being associated with one of said proximal end of said tubular barrel and said distal end of said pen body assembly, and said tab being located on with, and located to be wholly spaced from, the other end of said proximal end of said tubular barrel and said distal end of said pen body assembly such that said tab is accommodated within said U-shaped configuration of said bayonet thread with said closed bottom extending transversely to said tab to inhibit movement of said tab when said drug cartridge is interconnected to said pen body assembly.