Exploring Alternative Sterilization Modalities – Understanding and Overcoming Challenges

The primary concern of an MDM when selecting a sterilization modality should be whether the given modality can deliver the required sterility assurance level while not impacting the ability of the device to deliver its intended care to the patient. The key point is that the selected sterilization modality can address all complexities of the product as they relate to the sterility assurance process (e.g. shelf-life, potential for product promoting microbial growth before sterilization, etc.). EO and Gamma have long dominated the medical device industry for packaged terminally sterile products, and because they are trusted to meet this primary concern at high volumes, they will continue to be relied on. However, when considering the most appropriate sterilization modality from a holistic perspective (including speed, supply chain simplification, environmental impact, etc), alternatives to EO and Gamma may be worth exploring. This article (Medical Device Sterilization Modality Selection Decision Process) is a helpful starting point for asking the right questions at the start of the decision-making process.

For example, a product custom-made for a specific patient might have a relatively short shelf-life. Being able to sterilize the product in-house could enable quicker turn-around time, and a better ability to meet both healthcare professional and patient needs.

But of course, in our heavily regulated space, exploring these alternatives does not come easy for most. Understanding some of the top challenges that MDMs face when spending time and effort on adopting and validating alternative modalities may be helpful for organizations across the value chain to support these endeavors:

• Internal unfamiliarity – Change is often difficult. If a device manufacturer is familiar with a particular sterilization modality from the multifunctional perspective of operations, supply chain, R&D, biocompatibility, regulatory, etc., considering an alternative can seem daunting. These attitudes can lead to validating new products into existing sterilization modalities even if an alternative exists that could provide faster turn-around, lower cost, better material compatibility, etc.
• Regulatory -- There can be a perception that regulators will treat alternative sterilization modalities with more scrutiny, thus adding potential time and risk to an approval process. While some alternative modalities are less mature from a regulatory perspective compared to traditional modalities, several are making progress to aide in regulatory approval (e.g. ISO 22441 for VH2O2, AAMI TIR 124 for other modalities). Regulators may be open to discussions early and throughout the development and submission process, which can help reduce both perceived and actual risk to the success of the submission.
• Infrastructure requirements – Some alternative modalities are not compatible with all types of packaging, including paper and corrugate, requiring product to be sterilized in its primary packaging, and then packaged in secondary packaging after sterilization. While this can represent a change from a traditional sterilization modality and process, installing alternative modality sterilization equipment in-house can alleviate some of the challenges associated with sterilizing in primary packaging. While some alternative modalities are well-suited for installation in-line with manufacturing, such installations can involve large capital and personnel expenses. It can be difficult to see past the initial investment.
• Lack of information on material compatibility – Material compatibility is sometimes overlooked when considering a sterilization modality, but is critical to understand, especially as medical devices become more advanced and potentially sensitive to conditions in sterilization. Comparing effects of different alternate modalities can also be a challenge, as the cycles and conditions in various modalities may not be directly comparable. There are some industry-wide efforts (e.g. the Kilmer collaboration group on Material Compatibility, KIIP, 2024 Revision of AAMI TIR17) working to create more standardized ways of generating and sharing material compatibility data from some of these alternative modalities.

The best way to counter these obstacles is through education and experience with these alternative modalities, working cross-functionally with sterilization decision makers at your organization early and often.