FDA presenter: follow ISO methods for gamma and ethylene‑oxide sterilization and include requalification data

Chen stressed that when manufacturers use gamma irradiation or ethylene oxide to sterilize APIs or container closures they must perform validations consistent with ISO guidance and include recent requalification and dose auditing. She said deficiencies were often tied to not following ISO recommended methods or failing to include appropriate sample counts and requalification data.

Chen outlined ISO‑aligned dose‑setting approaches (average bioburden, fraction of positives, VDmax 25) for radiation dose setting and reminded submitters to include contract‑facility validation work when sterilization is outsourced.