A medical delivery system (200) having a container (202) and a dosing assembly (204), where the container is fastenable to the dosing assembly by a movement comprising a translatory movement followed by a rotational movement. One of the container and the dosing assembly comprises one or more blocking elements (207) movable between a blocking position and a non-blocking position responsive to the rotational movement. Each blocking element is able to engage the other one of the container and the dosing assembly. A container suitable for use in said medical delivery system.