The invention relates to a pre-filled injection device for apportioning a plurality of set doses of a liquid drug comprising. The housing of the injection device supports a non-replaceable cartridge containing the liquid drug. The cartridge is e.g. secured in a cartridge-holder being a part of the housing. A needle assembly comprising a needle cannula secured in a hub is slidable mounted to slide into contact with the cartridge. The tip of the needle cannula is covered by a telescopically movable shield movable from an extended position to a retracted position. The telescopically movable shield supports a cleaning chamber containing a cleaning solvent for cleaning at least the distal tip of the needle cannula between subsequent injections. The distal end of the housing supports a removable protective cap and the telescopically movable shield is guided relatively to the housing and coupled to the protective cap to follow movement of the protective cap.
