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November 2019


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Sonia Dekker <[log in to unmask]>
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The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Wed, 13 Nov 2019 20:27:22 +0000
text/plain (45 lines)

In qualification testing for the USP <61> method on tablets containing HPMC, I've experienced inability to distinguish individual Ps aeruginosa colonies as early as Day 1 at 32C on TSA.

The positive control plates show a range from 18-30 CFU, with colony sizes of 0.5mm to 1.5mm, while the test sample plates have instead a film of growth, sort of like one very large, irregular colony border ,with indistinguishable individual colony borders.

Has anyone ever had this experience before?

Thank you in advance,
Sonia Dekker

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