How does one determine the expiration date for a medical device and its associated packaging, and how does sterilization factor into this?
Typically, data generated in a stability study using pre- and post-sterilized samples in accelerated and real-time aging is used to determine an expiration date for the packaged product. The product and packaging (sterile barrier system) may each have a different shelf-life as determined by the stability studies performed by the MDM. There may be other considerations but in its simplest form, the expiration date on the medical device is based on the length of time the device performs as designed. Integrity testing plays an important role in verifying the maintenance of sterility and should be included in a shelf-life protocol.
A breach of package integrity most often occurs due to some event. Multiple distribution cycles, repeated handling in inventory, and exposure to various environmental conditions are some points at which events may occur resulting in damage to the protection a package provides a product. With some sterilization methods, polymers or other components may suffer long term affects that shorten the normal shelf-life. These are things that should be considered during the developmental stages of the product and package system. Guidance information to consider during the selection process can be found in AAMI TIR 17-Compatibility of materials subject to sterilization.