By Derek Peterson, EO Sterilization Study Director
Ethylene oxide (EO) is a widely accepted form of sterilization for medical devices that are sensitive to radiation or heat.
Batch release sterilization is ideal for medical device manufactures whose devices are very specialized and expensive to produce thus limiting device quantities, or devices that are not in the final device or packaging configuration where conducting a full EO sterilization validation would be impractical. Batch release sterilization is an efficient way to obtain small quantities of devices that are deemed suitable for human use regardless of the design or production phase of the device. Batch release sterilization can produce as much as hundreds or thousands of sterile product for human use or as little as one single device.
Batch release sterilization coordinated by Nelson Laboratories, Inc. (NLI) is performed under the guidelines of ANSI/AAMI/ISO 11135-1:2007 and AAMI TIR 16 utilizing the overkill method (half cycle full cycle method or cycle calculation approach) as described in ISO 11135 Annex B. This allows for a quick turn-around time (TAT) and the release of devices suitable for human use typically within 5 to 6 weeks (often times shorter). The number of devices required for testing is small, typically 31 devices (however, other variables may result in the need to consume additional devices).
NLI has several sterilization chambers located on site and can accommodate very small batches (under 0.25m3, 18” x 18” x 36” chamber dimensions) at our facility. Additionally, we have created and maintained great working relationships with many contract sterilization facilities that allow us to coordinate batch release sterilizations utilizing larger chambers. This allows great flexibility in meeting the needs of any device manufacturer.
Once the device is in its final configuration, cycle development testing such as Comparative Resistance can be performed to validate a process challenge device (PCD) and bioburden resistance testing. Thus reducing the number of devices needed for testing and reducing the TAT (typically 3 to 4 weeks).
Data generated during a batch release sterilization performed at a contract sterilization facility can be leveraged into a full validation with a couple of simple additions to the process (e.g. a validated PCD, temperature and relative humidity probes). This allows for the production of sterile human use products with each phase of the validation process