An injection device includes a cylinder having a cavity for receiving a liquid. A passage is connected to the cavity for inflow and/or outflow of the liquid. The passage can be connected to an injection component. A shut-off valve has a valve body and a flexible sealing ring with an opening. The valve body, proceeding from a release position in which the passage is freed, is at least partially movable through the opening of the sealing ring to a blocking position in which the valve body engages behind the opening so that movement of the valve body to the release position is blocked and the passage is sealed off against proximally directed flow. An adapter body is connected to the cylinder. The shut-off valve is arranged at a proximal end of the adapter body and at a distal end of the cylinder. The device can be used in a syringe.

An injection device includes a cylinder having a cavity for receiving liquid. A passage is connected to the cavity for inflow and/or outflow of liquid. The passage can be connected to an injection component. A shut-off valve has a valve body and flexible sealing ring with an opening. The valve body, proceeding from a release position in which the passage is freed, is at least partially movable through the opening of the sealing ring to a blocking position in which the valve body engages behind the opening so that movement of the valve body to the release position is blocked and the passage is sealed off against proximally directed flow. An adapter body is connected to the hollow cylinder. The shut-off valve is arranged at the proximal end of the adapter body and at the distal end of the hollow cylinder. The device can be used in a syringe.