A medical delivery system (100) comprising a container (102) which is adapted to be fastened to a dosing assembly (104). One of the container and the dosing assembly comprises a rotatable element (106) adapted to cooperate with the other one of the container and the dosing assembly, so as to lock/fasten the container to the dosing assembly. Furthermore, the present application relates to a container and a dosing assembly for use in the medical delivery system.