Pre-filled syringe

1 . A pre-filled syringe comprising:

a tubular container capable of accommodating a liquid medicine and a medicine, the tubular container being formed to have a tubular shape;

a front end gasket provided in the tubular container, the front end gasket being slidable with respect to the tubular container along an axial direction of the tubular container;

a rear end gasket provided rearward with respect to the front end gasket in the tubular container so as to define a space in the tubular container together with the front end gasket, the rear end gasket being slidable with respect to the tubular container along the axial direction of the tubular container;

an intermediate gasket provided between the front end gasket and the rear end gasket in the tubular container so as to partition the space into a front chamber adjacent to the front end gasket and a rear chamber adjacent to the rear end gasket, the intermediate gasket being slidable with respect to the tubular container along the axial direction of the tubular container; and

a plunger connected to the rear end gasket, the plunger being capable of pushing the rear end gasket toward a front end side of the tubular container along the axial direction, wherein

the tubular container has

an inner peripheral surface in contact with an outer peripheral surface of the front end gasket, an outer peripheral surface of the intermediate gasket, and an outer peripheral surface of the rear end gasket,

a protruding inner side surface having a shape that protrudes from the inner peripheral surface in a direction orthogonal to the axial direction and that extends along the axial direction, and

a receiving surface that receives the front end gasket in the axial direction,

a groove communicating the front chamber and the rear chamber with each other is formed in the outer peripheral surface of the intermediate gasket at a position at which the intermediate gasket faces the protruding inner side surface,

the plunger has

a connection portion connected to the rear end gasket,

a pushing portion that pushes the rear end gasket, and

a guide rib that guides movement of the pushing portion along the axial direction, the guide rib being formed to have a flat plate shape that extends from the pushing portion along the axial direction of the tubular container and that is along a plane including a center axis of the tubular container,

the protruding inner side surface is formed at a position facing the pushing portion in a pushing completion state in which the plunger is pushed into the tubular container until the front end gasket is brought into contact with the receiving surface, the intermediate gasket is brought into contact with the front end gasket, and the rear end gasket is brought into contact with the intermediate gasket,

the guide rib is provided with a recess having a shape depressed toward the center axis so as to be separated from the inner peripheral surface of the tubular container, and

a rear end portion of the recess in the axial direction is located rearward with respect to a rear end portion of the protruding inner side surface in the axial direction in the pushing completion state,

in the pushing completion state, the pushing portion and a front end portion of the recess in the axial direction face the protruding inner side surface, and a rear end portion of the recess in the axial direction is located rearward with respect to a rear end portion of the protruding inner side surface in the axial direction.

2 . The pre-filled syringe according to claim 1 , wherein the tubular container has an abutment portion in abutment with a region of the guide rib on a rear end side with respect to the recess in the axial direction in a state in which the pushing portion does not push the rear end gasket.