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December 2003


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Scott Sutton <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Tue, 16 Dec 2003 10:20:50 -0600
text/plain (67 lines)
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 end
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 have
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 (Line
B remember is sterilized in bulk by heat).  If so, then why do samples from
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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