Stopper processing

Hi All

Does anyone have any advice / useful background info on challenges used for the validation of rubber stopper sterilisation cycles? I’m investigating using stoppers spiked with g. stearothermophilus as part of a study soon so it would be handy to know of any problems that are likely to appear.



Recovery would be the biggest concern. Once spiked, how are you going to demonstrate repeatable recovery results? Then you have to validate that method. Why wouldn’t you just use stearo vials or strips placed in the most difficult to heat location?

recovery of what? Procedure here investigates growth / no growth after incubation of processed BIs.
We currently use vials here attached to standalone datalogger probes with autoclave tape. the issue here is that the tape comes off when it’s wet and the vials are partially ‘killed’ by the heat of the WFI already. the water is also an issue with using strips.
Other methods bar spiked stoppers are also being investigated during this study but i wanted to ask about the spiked stoppers specifically as they haven’t been used in my workplace yet.

I was writing about the recovery of the stearo. How do you demonstrate the recovery of it before sterilization. You should be able to show the amount that you can reduce, 5 log reduction or so. But without a known quantity, how do you do this?

As far as tape is concerned, we use a nylon tape instead of autoclave tape for just the reason you describe. In addition, the stearo is partially killed by the hot WFI probably too.

I’ll check with the people at my new company, since I heard they use spiked stoppers. My new company provides sterilized stoppers to pharma.

Ah right,we got spiked stoppers supplied by a specialised company so we know the D value, population etc.
Please do ask around,