Medical Devices

Gamma sterilization of medical devices

According to the US Center for Disease Control, “Sterilization means the use of a physical or chemical procedure to destroy all microbial life, including highly resistant bacterial endospores*.” Cobalt-60 is an isotope that produces gamma irradiation.
* Source: Medical Device Industry Development and Investment CEO Summit 2012

Nordion’s Role

Throughout the global marketplace, Nordion’s gamma expertise plays an important role in the sterilization of medical devices—from contract relationships with suppliers of raw Cobalt-60 to manufacturing Cobalt-60 into a usable form as well as designing and manufacturing irradiation processing equipment to delivering Cobalt-60 to contract sterilization service providers and medical-device manufacturers. As the world becomes a more global marketplace – the role for gamma processing is growing.

Applications of Combination Devices and Implantable Devices

Single-use Medical Devices

As the global healthcare field grows, the need for safe and sterile products is more paramount than ever. Gamma sterilization is a simple, proven process that’s safe, reliable, and highly effective at treating single-use medical devices. With the ability to penetrate products while sealed in their final packaging, gamma sterilization economizes the manufacturing and distribution process, while still ensuring full sterility of the product.

Tissue-based Devices

Sterilization of tissue-based devices by gamma irradiation is conducted routinely and is gathering momentum in the healthcare industry. Tissue-based devices come from human donors. There are no living cells in the bone grafts, tendons, ligaments and various other tissues. While not currently required by regulatory standards, tissue banks are choosing to terminally sterilize tissue-based devices with gamma in order to increase patient safety. This demonstrates the value added by gamma sterilization to this class of products.

Combination Devices

A combination device is a medical device combined with a tissue or pharmaceutical or other component that falls within one or more regulatory standards, such as drug-eluting stents. Sterilization can affect drug properties and material properties, so sterilization by gamma irradiation is applied to ensure that the combination device’s sterility and functionality are maintained.

Implantable Devices

Implantable devices include orthopedics (e.g. knees), stents, heart valves and more. Metal and polymers present a challenge to some sterilization modalities. Ethylene Oxide (EO) gas, for example, is inefficient because of tight interfaces inherent in plastic to metal transitions in orthopedic devices; for example, E-Beam is ineffective because some implantable devices are high density or heterogeneous in nature. Gamma is highly efficient for sterilization of implantable devices; in fact, the highest percentage of sterilization modalities for orthopedics is gamma. Additionally, many implantable devices are high value and therefore depend on a reliable process to ensure quality control and prevent the potential for lost product due to processing faults.


Sterilization by gamma irradiation is advantageous for a wide range of pharmaceutical products. Due to the high demand for terminally sterilized products in the pharmaceutical industry, gamma has proven itself to be an effective method as indicated by its acceptance in the European Pharmacopeia and more recently drafted into the U.S. Pharmacopeial Convention. Some of the advantages of gamma over other modalities include high penetration power, isothermal character (small temperature rise) and no residues. It also provides a better assurance of product sterility than aseptic processing and lower validation demands.

Cobalt-60 Sterilization Saves Lives (video courtesy of Bruce Power)
7 Billion. The global population as of 2011
164 Billion. The US dollar value of the global medical device industry*
40% of single-use medical devices sterilized globally using Cobalt-60**

*Source: Medical Device Industry: Market Reasearch Report, Statistics and Analysis
**Source: International Irradiation Association (iia)