TWO COMPARTMENT SYRINGE

摘要

A syringe comprises a barrel having a forward end adapted to be fitted with a needle assembly, a plunger slidable within the barrel and having a plunger seal at its forward end, and an annular chamber defined between the plunger and a wall surrounding the plunger. The interior of the barrel and the annular chamber may be pre-filled with two components which are to be admixed before administration. Retraction of the plunger is effective to establish communication between the interior of the barrel and the annular chamber to allow the pre-filled components to admix within the barrel interior. In a modification, only the annular chamber is pre-filled with a drug to be administered, the drug being transferred to a location forwardly of the plunger seal in response to plunger reaction in readiness for administration by depression of the plunger.