EtO Sterilisation of Syringes

Hi All,

Whilst looking at a packaged syringe that had been sterilised using EtO a question came to mind. How is it possible for the Ethylene Oxide to reach, and therefore kill, the bugs that are present around the rubber plunger, which is pressed firmly up against the barrel. The plungers are always "depressed" during sterilisation, and will go on to expose the previously hard to get at area in the process of drawing up the liquid to be injected, surely contaminating it in the process. Am I missing something?

Regards,

JoCam

 

Jo,

You're generally right. This problem exists for all EO sterilised medical devices that employ press fits. There are some creative solutions (e.g. an elastomeric material that is permeable to EO gas but not to liquids) but essentially it boils down to the sterilisation process validation - if it shows that at worst case a sufficient SAL (sterility assurance level, i.e. absence of viable organisms) is achieved then the device qualifies as sterile. I don't know the specifics of the syringe you were looking at so I don't know how they solved the problem and how robust their validation was.

If I was to source a sterile syringe I would be cautious of EO sterilised ones that come from all but the most reliable sources. I would also challenge the supplier with those questions and ask for supporting evidence.

Cheers,
Ronen.