Patent ID: 6866142

Claim:
A gas syringe unit for injecting a gas into the body of an animal, said syringe unit comprising: a prefilled gas syringe containing a unit dose of a pharmaceutically acceptable gas, said gas being substantially in the absence of air, said syringe including a syringe barrel with a gas delivery outlet, and a plunger slidably received in said syringe barrel for expelling said unit dose of said gas through said delivery outlet; and a container having an internal volume and being configured and arranged to enclose said gas syringe within the internal volume and so to prevent contact of said gas syringe with air and contaminants external to said container, the internal volume containing said pharmaceutically acceptable gas substantially in the absence of air, wherein said container is made of a material characterized as having a gas transmission rate sufficient to essentially prevent said pharmaceutically acceptable gas from diffusing out of the container internal volume and to essentially prevent atmospheric contaminants from diffusing into the container interior volume, and said container having an internal pressure to inhibit diffusion of air and contaminants into said container.