One embodiment is directed to a pre-filled safety syringe system, comprising a syringe body; a plunger tip positioned within the syringe body; a needle assembly removably coupleable to the distal end of the syringe body such that a medicinal fluid may be transferred through a retractable needle coupled to a needle housing comprising the needle assembly upon insertion of the plunger tip relative to the syringe body; and a plunger control assembly coupled to the plunger tip and configured to facilitate manual insertion of the plunger tip relative to the syringe body; wherein upon insertion and release of the plunger tip, a retraction load coupled between the syringe body and the plunger tip causes the plunger tip to be proximally withdrawn, pulling the retractable needle proximally relative to the needle housing to a safe locked and retracted state.

One embodiment is directed to a safety syringe system, comprising a syringe body; a plunger tip positioned within the syringe body; a needle assembly removably coupleable to the distal end of the syringe body such that a medicinal fluid may be transferred through a retractable needle coupled to a needle housing comprising the needle assembly upon insertion of the plunger tip relative to the syringe body; and a plunger control assembly coupled to the plunger tip and configured to facilitate manual insertion of the plunger tip relative to the syringe body; wherein upon insertion and release of the plunger tip, a retraction load coupled between the syringe body and the plunger tip causes the plunger tip to be proximally withdrawn, pulling the retractable needle proximally relative to the needle housing to a safe locked and retracted state.

A pneumatic retractable syringe has a plunger having an interior retraction lumen. The plunger and syringe barrel have cooperating locking elements so that the plunger is locked after use within the syringe barrel. After injection of medicament is completed, the needle is retracted into the lumen by compressed gas that is released from a gas cell within the syringe when the gas cell is ruptured just before the plunger reaches the end of its downstream path of travel.

A pneumatic retractable syringe has a plunger having an interior retraction lumen. The plunger and syringe barrel have cooperating locking elements so that the plunger is locked after use within the syringe barrel. After injection of medicament is completed, the needle is retracted into the lumen by compressed gas that is released from a gas cell within the syringe when the gas cell is ruptured just before the plunger reaches the end of its downstream path of travel.