Bioequivalence and Bioavailability Forum

Hi,

I know this is Off Topic, but maybe someone can point me in the right direction, or know some forum where someone can help me?

I'm performing a preservative efficacy test on an oil based pharmaceutical product.
After trying with different preservatives (benzylalcohol, methyl and propylparahydroxybenzoate, propyl galate, some combinations) and different concentrations (up to 4 mg methylparahydroxybenzoate, just to test) the conclusion is always the same: PET test failed.

Now I'm wondering if it's possible the innoculum forms some micels in the oil, so that the preservative won't be able to do his job?

Any ideas about what is going on, or how to get the test passed?
Or is this test not needed in oil based formulations?


Best regards

Ace