Vented vial stopper for processing freeze-dried products

摘要

An vented vial stopper for use in processing freeze-dried products is provided. The stopper includes a vent passageway that is covered with a waterproof and moisture vapor permeable membrane to allow the venting of moisture during the freeze-drying process. The membrane also extends to cover most or all of the exposed surface of the stopper to protect the stopper from chemical attack during processing.