Irradiation of advanced health care products – Tissues and biologics

• MPN testing can provide good bioburden results for tissue/biologics.
• There are appropriate situations to pool products for bioburden testing.
• Options on dealing with bioburden results of “less-than” the limit of detection.
• Underestimation and overestimation of bioburden and the dangers of both.

Radiation sterilization of tissues and biologics has become more common in recent years. As a result it has become critical to understand how to adapt the typical test methods and validation approaches to a tissue or biological product scenario. Also data evaluation sometimes becomes more critical than with traditional medical devices because for many tissues and biologics a low radiation dose is required. It is the intent behind this paper to provide information on adapting bioburden tests used in radiation validations such that the data can be most effectively used on tissues and biologics. In addition challenges with data evaluation are discussed, particularly the use of less-than values for bioburden results in radiation validation studies.