It’s great to have a long post! I’ve put this query up a couple of times with no joy.
can you find out for me how they treat the paperclips prior to using them please? i read a forum on the internet from the PDA which mentioned in one post that stainless steel wire was used by some people which i guess is fairly equivalent to using a paperclip. i also tried putting thermocouple wire through the stoppers on one occasion which was fine also. i used depyrogenated scissors to poke the holes through for them though. i wanted to stick with the paperclips out of ease of use more than anything.
can i also ask you are the stoppers that you are sterilising wet or dry??
wrt the micro dept thread, the issue is that depyrogenating something is not sterilising and there doesn’t seem to be a reason why the paperclips would be causing failures or passes. also, i had 4 failed cycles using sanitised (IPA + flame) paperclips and another 4 clean cycles with depyrogenated ones. that was until the other day with the bigger load. i did however put more stoppers than usual on the paperclips so the failure may just have been down to using too many all lodged together. (steam penetration issues possibly).
ready to use stoppers wouldn’t work here from a QA and regulatory point of view. stoppers have been processed as part of the overall manaufacturing process for years so it’s not going to change that drastically now. stopper processing works for us here - the validation approach i am working on is the new bit. this is changing over from using ampoules to spiked stoppers.
with respect to dryness, that is a whole different topic of itself!! i have done quite a bit of work around this area also due to a process upgrade in the facility in which i work. stopper dryness is dependent on a lot of factors - the stopper material characteristics, length of sterilisation (this part makes them the wettest apparently), length of dryness, method of drying etc etc. there’s a number of good articles i found recently. i have them on the computer if you want me to send them to you??