In our GMP News
of 6 August we have drawn your attention to FDA's new Q&A page.
This page is the successor of the Human Drugs
cGMP Notes.In the 'Production and Process Controls' section, among
others the following case can be found: In a company, several media fill
failures occurred. As usual, the employed TSB (tryptic soy broth) had been
sterilised by means of a 0.2 µm filter. The subsequent investigation
could not uncover any plausible reason for this result. The contaminating
organism could be neither isolated nor recovered by means of conventional
tests. What had happened?
With the help of an RNA analysis, the cause could be clarified. The
organism was identified as Acholeplasma laidlawii and also
detected in the TSB media source. It belongs to an order of mycoplasma and
can penetrate a 0.2 µm filter due to its characteristics (no cell wall).
Thus, it had not been removed from the medium through the sterile
filtration.
As a consequence, the company now uses a 0.1 µm filter, which retains
this organism. (This is just to solve the problem - the FDA does not
require these filters in general.) The firm will change to sterile, irradiated TSB as soon as
it becomes available. In addition, they have started monitoring for mycoplasma and revalidated their cleaning procedure
in order to verify its removal.
