Delivery apparatus with mechanism preventing rearward movement of a piston disposed therein

摘要

A delivery apparatus in the form of a syringe assembly with a piston and including a mechanism for preventing withdrawal of the piston. The syringe is preferably prefilled and sterilized to provide a sterile syringe assembly with sterile contents. By preventing withdrawal of the piston, 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.