The invention refers to an injection arrangement (1) comprising a replaceable container cartridge (2) for a flowable drug (5), the container cartridge (2) comprising a deformable bag (4) arranged inside and sealed against a rigid outer casing (3), the deformable bag (4) being arranged for holding the flowable drug (5) and in fluid communication with an outlet (6), the rigid outer casing (3) fillable by a displacement fluid (7) for displacing the deformable bag (4), the injection arrangement (1) further comprising a reservoir (8) for the displacement fluid (7) and a pump (9) for pumping the displacement fluid (7) from the reservoir (8) into the rigid outer casing (3) and/or from the rigid outer casing (3) into the reservoir (8) via a fluid channel (10).
