Patent ID: 8409150

Claim:
An ampoule for a flowable substance comprising: an ampoule body comprising an interior space for receiving the flowable substance and an inner circumferential surface having a guide region and a sealing region, wherein the guide region and the sealing region are positioned along a longitudinal axis of the ampoule body; a piston disposed in the interior space of the ampoule body such that the piston is slidably displaceable along the longitudinal axis of the ampoule body in a direction of displacement, the piston comprising at least one sealing element for forming a seal with the inner circumferential surface of the ampoule body in a contact zone on an outer circumference of the at least one sealing element; a second blocking device which prevents movement of the contact zone from the sealing region to the guide region, wherein: the second blocking device comprises a second ampoule-body-side stop, a piston-side stop and a sliding surface; the at least one sealing element has a first compression state when the contact zone is in the guide region of the inner circumferential surface; the at least one sealing element has a second compression state when the contact zone is in the sealing region such that the inner circumferential surface forms a fluidic seal with the at least one sealing element and when the at least one sealing element is in the second compression state, the at least one sealing element has a greater degree of compression than when the at least one sealing element is in the first compression state; and the interior space of the ampoule body has a cross section which deviates from circularity in a direction perpendicular to the direction of displacement and along the longitudinal axis of the ampoule body.