With 15 years of experience consulting on polymers in the medical device field, Stephen Spiegelberg has spotted plenty of mistakes to avoid when it comes to sterilizing medical plastics.
Here are two major mistakes that Spiegelberg, president of Boston-based Cambridge Polymer Group, says you should avoid:
1. Choosing the Wrong Sterilization Method
There are three major sterilization methods: ethylene oxide, gamma radiation, or electron beam radiation.
"The common issue we see with companies new to this sort of process is that they'll plunge into one of the ionizing radiations, either gamma or electron beam, without consideration of what it is doing to the plastic itself," Spiegelberg says.
|See Spiegelberg discuss failure analysis of medical plastics on Thursday, October 16, at MD&M Chicago.|
Use ethylene oxide, and the packaging will need to have permeability to the ethylene oxide, and some devices just don't lend themselves to ethylene oxide, which is more of a surface sterilization process.
The radiation sterilization might be cheaper, too.
But Spiegelberg says the advantages to be had from using radiation sterilization could be more than cancelled out because brittleness or other changes to the properties of the plastic could potentially crop up, immediately or over the longterm, with such radiation exposure.
2. Placing Sterilization above Clean
Your plastic medical device parts might be sterile, but are they clean?
That question became much more important after the roughly $1 billion in lawsuit settlements that Sulzer Orthopedics, now part of Zimmer, made over a decade ago over faulty hip and knee implants.
Spiegelberg was involved with a taskforce that examined what went wrong.
"They changed their manufacturing process, which resulted in a series of things that happened downstream. At the end of the day, it resulted in some manufacturing residue, some lubricants, being left on the medical product that led to an adverse biological response," Spiegelberg said.
The Sulzer issues changed the climate.
"Up until that point, manufacturers were certainly aware that how clean medical device components are is important. But it certainly was second tier to how sterile medical products are. ... As we say, ''You can have sterile dirt, but it's still dirt,'" Spiegelberg said.
Spiegelberg says the solution is more control and understanding of the manufacturing line: "They need to know how much their residue load is--both in quantification and identification--so that if there's a problem down the road, they can get ask if residue levels changed."
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