Suggestion: For samples that fail GPQ consistently a systematic error in
filling or test procedure is a possibility. Check for any differences, tiny
or larger, in the total test process, begining from taking the sample,
storage, analyst etc. Also check the filling process end-to-end.
Problems of thus type often follow a variation of "Parkinson Law" . The
cause is difficult to find. When you find it, you will probably curse
yourself for overllloking the detail. And if the explanation or correction
you identify is complex, it is usually wrong.
[log in to unmask]
----- Original Message -----
From: "Scott Sutton" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, December 16, 2003 10:20 AM
Subject: [PMFLIST] Request for Help on Media Fill GPQ
> Here is an interesting case study I have been asked to post anonymously:
> Two aseptic filling lines:
> Line A - Product is filtered sterile immediately before aseptic filling
> Line B - Product is bulk sterilized (heat) and then aseptically filled
> The problem:
> Filled bottles (Line B) from the beginning of the run fail GPQ for B
> subtilis (and continue to fail on subsequent challenges of additional
> Bulk media from both lines pass GPQ for all organisms
> Filled units from the end of the run (Line B) pass GPQ
> Filled units from Line A always pass GPQ, no matter from beginning or
> of run
> Both media fills used same manufacturer's lot of TSB
> CIP is validated
> No evidence of sanitizers can be found in the media filled bottles.
> When I first saw this question I thought that the CIP was suspect, but
> been assured that all is in place, and there is no evidence of residual
> sanitizer being washed off the equipment into the filled units. Next
> thought was that they had baked the TSB too much to support B subtilis
> B remember is sterilized in bulk by heat). If so, then why do samples
> the bulk and the end of the fill run support growth? Unfortunately, there
> are no retains from the different sampling events to evaluate.
> BTW - all other organisms used for GPQ (based on Sterility Test B/F plus
> environmental) were fine.
> Anyway, I held this post a couple of days to get the above clarification.
> Does anyone have any ideas?
> Scott Sutton
> Moderator, PMFList
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