With fewer safety risks and a faster turnaround time, VPA sterilization can allow medical device OEMs to sterilize product in house. 

Vicki Lanka 

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Like all manufacturers, medical device companies are constantly looking for ways to optimize their production efficiency. Because patient safety and FDA compliance are top priorities, effective and dependable sterilization is a crucial part of the manufacturing process. However, many medical device manufacturers currently rely on off-site contract sterilization services that introduce inefficiencies, added costs, and risks into the production cycle.

Vaporized peracetic acid (VPA) sterilization, in which room-temperature VPA is injected into a pressurized chamber to eliminate surface contaminants, is changing that. Because this method allows for quick turnaround time and can be performed on an OEM's production floor, it offers device manufacturers an alternative to ethylene oxide (EtO) sterilization in some cases.
 

VPA vs. EtO

Though still popular in the medical device industry, EtO sterilization has several drawbacks when compared with VPA methods. 

EtO facilities typically require infrastructure investment to comply with safety regulations, so EtO sterilization is typically performed on an off-site, contract basis. In order to make contract sterilization processes economically feasible, manufacturers must assemble large batches of product, which requires additional time, effort, and on-site storage space. Delivering pallets of this inventory to and from third-party sterilization facilities also adds significant logistics, transportation, and packaging costs, and it introduces the potential risk of delayed customer shipments. These issues can lead to delays and interruptions for manufacturers.

In contrast, VPA sterilization systems can be installed on an OEM's production floor and can handle disinfecting both small and large quantities of products more quickly than EtO--in a matter of hours versus days. Having an on-site, room-temperature VPA system allows medical device manufacturers to sterilize items in less time and with greater efficiency than is possible EtO. 

VPA sterilization systems can be relatively easy to install. The only factory floor space required for VPA sterilization systems is for the machines themselves. The machines have their own ventilation filtration systems built in, so no additional ventilation is required. Sterilization chambers can range in size from 417 L for small production batches up to 3000 L or more for large quantities. 

Another drawback of EtO is the fact that the process results in carcinogenic chemical residuals. Safety and environmental risks with VPA are lower because the process breaks down into carbon dioxide, oxygen, and water. Since it doesn't result in carcinogenic fumes, VPA also doesn't require a lengthy aeration period. As a result, the product does not have to leave the facility until it's ready for delivery to the customer.

VPA sterilization is also compatible with a broader range of materials used in medical device development than EtO sterilization. Thanks to its gentler, room-temperature process, VPA enables medical manufacturers to sterilize chemical and heat-sensitive materials that are off-limits with EtO. For example, copper, is not harmed by VPA. VPA can also be safely used with polystyrene materials, bioresorbable polymers including PLA and PLGA, polyacetals, nylon, various polyurethanes, and elastic polymers such as synthetic rubber. According to one study, the VPA process has been verified as compatible, safe, and effective for sterilizing 92 different materials.

Kaizen Analysis Shows VPA Efficiency Advantages

Many U.S. manufacturers have adopted the Japanese Kaizen philosophy of continuous improvement to evaluate and optimize their production processes. Kaizen is a successful method for developing a lean manufacturing culture and identifying cost savings and new efficiencies.

Minneapolis-based Medivators, which makes components to assist with endoscopic surgery, recently used Kaizen analysis to determine whether installing VPA sterilization on-site would improve its manufacturing efficiency for its endoscopy products in Conroe, TX. The company had previously worked with a contractor to sterilize its products via an EtO process. 

During a Kaizen review, the process improvement team completed a cost-benefit analysis of installing a 3000-L VPA machine on site. It determined that an in-line sterilization system would reduce processing time by as much as 70%.

Previously, Medivators had to build up inventory that was unnecessary and unusable until a truckload for EtO processing could be filled.  Once the company shipped the product off site, the facility would sterilize its devices and then ship them back. Medivators would then have to aerate the devices, as EtO is a potentially hazardous chemical that must be outgassed to a safe level before the product can be usable. 

When considering the entire sterilization process, the off-site EtO sterilization cycle time took between 10 and 12 days, and required a significant amount of square footage for pre- and post-sterilization inventory storage. With VPA, the sterilization and business intelligence validation steps would take one to three days.

Conclusion

VPA sterilization offers quick turnaround times and can be performed by OEMs in-house with equipment that is relatively easy to install. The process is free from carcinogenic chemical residuals found in EtO sterilization and is compatible with a broader range of materials. As medical device manufacturers look to cut costs and speed products to market while maintaining FDA compliance, VPA sterilization can provide another weapon in their arsenal.   

Vicki Lanka is the marketing manager for Revox Sterilization Solutions. Reach her at [email protected].