MECHANISM PREVENTING REARWARD MOVEMENT OF PISTON SYRINGE

摘要

A delivery apparatus (20) in the form of a syringe assembly with a piston (30) and including a mechanism for preventing withdrawal of the piston (52, 60). The syringe (20) is preferably pre-filled and sterilized to provide a sterile syringe assembly with sterile contents. By preventing withdrawal of the piston (30), contact of the sterile contents with the exposed portion of the syringe barrel behind the piston and the consequent risk of contamination arising therefrom are avoided.