PREFILLED SYRINGE AND METHOD OF STERILIZING A PREFILLED SYRINGE

A prefilled syringe (1) comprises: a barrel (2) having a hollow interior, an orifice and an opening opposite to the orifice; a stopper (4) arranged in the hollow interior of the barrel (2) thereby defining a sealed chamber (21) in the interior of the barrel (2), wherein the stopper (4) is displaceable in the interior of the barrel (2) thereby varying a volume of the chamber (21); a liquid within the chamber (21) of the barrel (2); and a plunger (3) extending through the opening of the barrel (2). The stopper (4) expels the liquid out of the barrel (2) via the orifice when being moved towards the orifice by the plunger (3) such that the volume of the chamber (21) is reduced. The plunger (3) comprises a proximal portion (31), a distal portion (33) and a rod portion (32) extending along an axis between the proximal portion (31) and the distal portion (33). The barrel (2) is equipped with a backstop structure (53). The rod portion (32) of the plunger (3) has a rigid axial section (325) and a series of flexible arms (321) projecting from the axial section (325). The arms (321) of the series of flexible arms (321) are inflected when arranged in the interior of the barrel (2). Each arm of the series of flexible arms (321) ends at another position in relation to the axis of the plunger (3). The backstop structure (53) is arranged to abut the end (3214) of the arms (321) of the series of flexible arms (321) to prevent a movement of the plunger (3) along its axis (7) in a distal direction (72)..