A mixing and/or reconstitution system for emptying a first material into a vial containing a second material and drawing the mixed and/or reconstituted material into an injection device, the mixing and/or reconstitution system comprising - an adaptor (100, 100', 100", 300), - the injection device (140, 340), - a first reservoir (121, 341) containing the first material, wherein the first material is a fluid, and - a user-operatable trigger (110, 126, 344), wherein the adaptor (100, 100', 100", 300) further comprises - a first attachment location adapted to attach the vial (160, 360), wherein the vial (160, 360) contains the second material within a second reservoir (161, 361), wherein the second material contains a medicament formulation, - a first connection element (107, 307), - a flow channel (108, 108a, 308) providing fluid communication of a switching element (155, 355) and the first connection element, characterized in that the injection device (140, 340) is an integrated injection device (140, 340) removably attached to the adaptor (100, 100', 100", 300) and comprises the switching element (155, 355), and that the adaptor (100, 100', 100", 300) further comprises: - a sensing arrangement (104, 117, 346, 385) for detecting a pre-defined position of the vial (160, 360) at the first attachment location, wherein the sensing arrangement (104, 117, 346, 385) is adapted to take an initial first state and a second state different from the first state and indicating that the vial (160, 360) is in the pre-defined position at the first attachment location, and - an interlock element (114, 346) which fixes the first reservoir (121, 341) in a pre-defined position with regard to the adaptor (100, 100', 100", 300) thereby preventing operation of the trigger which is connected to the first reservoir (124, 341), and which is adapted to allow operating the trigger (110, 344) by the user in order to establish a fluid communication between the first connection element (107, 307) and the first reservoir (121, 341) only if the sensing arrangement (104, 117, 346, 385) detects the pre-defined position of the vial (160, 360) at the first attachment location. - an adaptor (100, 100', 100", 300), - the injection device (140, 340), - a first reservoir (121, 341) containing the first material, wherein the first material is a fluid, and - a user-operatable trigger (110, 126, 344), wherein the adaptor (100, 100', 100", 300) further comprises - a first attachment location adapted to attach the vial (160, 360), wherein the vial (160, 360) contains the second material within a second reservoir (161, 361), wherein the second material contains a medicament formulation, - a first connection element (107, 307), - a flow channel (108, 108a, 308) providing fluid communication of a switching element (155, 355) and the first connection element, - a sensing arrangement (104, 117, 346, 385) for detecting a pre-defined position of the vial (160, 360) at the first attachment location, wherein the sensing arrangement (104, 117, 346, 385) is adapted to take an initial first state and a second state different from the first state and indicating that the vial (160, 360) is in the pre-defined position at the first attachment location, and - an interlock element (114, 346) which fixes the first reservoir (121, 341) in a pre-defined position with regard to the adaptor (100, 100', 100", 300) thereby preventing operation of the trigger which is connected to the first reservoir (124, 341), and which is adapted to allow operating the trigger (110, 344) by the user in order to establish a fluid communication between the first connection element (107, 307) and the first reservoir (121, 341) only if the sensing arrangement (104, 117, 346, 385) detects the pre-defined position of the vial (160, 360) at the first attachment location.