Discussion Of Vial Closures And Stoppering Force In Pilot Freeze-Dryers

By Leslie Mather, SP Scientific

SP Scientific, as a supplier of Production and Research and Development freeze dryers over the last decades, has encountered various container-closure systems. On occasion, we are challenged with regard to equipment being able to properly seal a customer’s selection of container--closure system which is typically a glass vial and rubber stopper that is pressed down into the vial during a stoppering step at the end of freeze drying. This became a more frequent problem as dosages and containers decreased in size because this configuration typically requires more force per square inch to create proper stopper seating in the vial. In addition, we have found that vials for R&D are not always processed as they might be for production and this may create a significant impediment to properly seating the stopper in an RR&D freeze dryer due to an absence of lubricant that may be part of the processing of vials for production.