When it comes to choosing the right container closure system, a significant amount of focus is directed at addressing issues that may be a risk to safety and efficacy of the parenteral drug before it is introduced to a patient. Examples are testing of container closure integrity (CCI) and drug stability. Prior to drug administration by a health care professional, the rubber stopper is pierced with a needle, at least once. Stopper puncture testing also needs to be considered, especially if the closure system will be used in a multi-dose application.