An alignment device for coupling a liquid drug cartridge with a longitudinal cartridge axis and a constricted neck portion with a cap and a piercable septum distal from the neck portion with an adapter is presented. The septum is perpendicular to the cartridge axis. The device comprises an adapter cannula with a longitudinal cannula axis to pierce the septum and a proximal cartridge engagement structure for axial aligned engagement with a distal end section of cartridge body. The device further comprises a distal adapter engagement structure for axial aligned engagement with the adapter. A coupling of the cartridge with the adapter is enabled via the alignment device. The adapter and the cartridge are, during the coupling, aligned by the cartridge engagement structure and the adapter engagement structure, respectively relative to each other such that the longitudinal cartridge axis and the longitudinal cannula axis form a common longitudinal axis.