Bacteriostasis/Fungistasis Testing

[mpfizer]

Hi,

Is the B & F test same as sterility test ?

Is it used over and above normal sterility testing ?

What are the ISO standards or USP for B & F testing?

Thanks
michelle

 

[planB]

Michelle,

No, B&F testing is intended to determine whether or not the product has intrinsic antimicrobial properties that inhibit microbial growth, potentially introducing an undesired bias falsifying your sterility test. Test of sterility is a separate test. The related standard is ISO 11737-2:2019.

Hope this helps,

 

[mpfizer]

Michelle,

No, B&F testing is intended to determine whether or not the product has intrinsic antimicrobial properties that inhibit microbial growth, potentially introducing an undesired bias falsifying your sterility test. Test of sterility is a separate test. The related standard is ISO 11737-2:2019.

Hope this helps,

Thanks
We manufacture orthopedic implants made of steel , the lab where we get sterility test done says that B & F test is only done on implants with drug coatings ?? so we don't require to do the test ...........any idea if that is right ?

Thanks

michelle

 

[chris1price]

I think your lab may not have complete knowledge of the subject. Bacteriostasis and Fungistasis should be considered whenever a sterility test is being performed, including device sterilisation processes. It has nothing to do with drug coatings

 

[planB]

Michelle,

concurring with chris: you may want to interprete the lab's note the following way: typically, steel is known to not to inhibit microbial growth, and drug coatings are sometimes known to have antimicrobial properties.

However, there are high chances that regulators will ask for objective evidence for the lab's educated guess. So I would recommend to not skip this fast and cheap test according to ISO 11737-1, section A.6.6:

Product being tested should be screened to determine if any inhibitory substances are released into the medium which can cause a false negative (see A.7). This is performed by the inoculation of low numbers of representative organisms into the medium containing a product as is carried out in the bacteriostasis/fungistasis test.

Hope this helps,

 

[mpfizer]

I think your lab may not have complete knowledge of the subject. Bacteriostasis and Fungistasis should be considered whenever a sterility test is being performed, including device sterilisation processes. It has nothing to do with drug coatings

Hi,

you mention "whenever a sterility test is being done " please clarify...do you mean every time a sterility test is done ( as per USP 71 ) after gamma sterilization for batch release or when the sterilization validation is done and tested as per ISO 11737?

Thanks

michelle

 

[planB]

Michelle,

bacteriostatic and fugistatic properties are typically determined by the materials used in your device . So you typically perform B&F testing during (initial) validation and again when you change something in your product that might have an impact on the initial B&F test results.

Note that within the framework of ISO 11137-1 you release product from routine gamma sterilization by verifying whether the delivered routine dose for the batch is in the specified range; You do not perform tests of sterility when you release routine product.

Hope this helps,