A sealing element is suggested, in particular one for closing primary packaging for medications, that has at least two parts, which touch each other at least in some areas. This is characterized in that steam-permeable channels are provided for sterilization of the contact surfaces. In addition, a method is suggested for manufacturing a syringe system with a sealing element. This is characterized by the steps—preliminary assembly of the sealing element, —sterilization of the sealing element, —final assembly of the sealing element.