Water content test - Finished product specifications

Is it necessary to carry out ‘Water content’ test for Tablets at Finished Product Release Specification even if the API is not moisture sensitive?

How can we justify to Regulatory authority if we do not wish to perform this test at FP Specification?

Yes, you must perform the test since the moisture range is critical in the compression of the formulation in order to make tablets.

Thanks for your reply and i agree with this. However, we are already assessing the moisture content before compression (i.e. at the time of Granulation).

You might not need to call water content a “Release criteria”, yet you might still want to control and monitor it for process control.

Personally I would want to test for water content, because if something goes wrong you can elinimate that possible source of error. Moreover, water content is considered a “critical process parameter”, which can directly impact the product quality. Knowing, controlling, and testing for critical process parameters is required in the new FDA 2011 guideline for process validation.

The intent isn’t to test the finished product - it is to control/test what can affect the finished product. In this case water affects tablet characteristics, and is a critical parameter.

You said you’ve already tested it during granulation. I had an experience with a hygroscopic (water adsorbing) compound, which was processed in an uncontrolled (for RH) environment. We couldn’t control the RH of the room, so we controlled the time. Knowing that time + RH both affect the water content of the product. Thus time was controlled, monitored, validated, and documented on batch records.

I guess, overall, I would ask if you can do a quick on-line test of RH, but not have RH as a release test? I think that is the best value of RH testing for your product.