Bioequivalence and Bioavailability Forum

Dear All,

First, let me correct my first post:
"Nice page" --> incorrect
"Professional page" --> correct

Now, I'm used to use the search button, but can't find a thread covering my dilemma which is the following:

I was addressed these questions:
1. Check whether the inactive ion metabolized to the stated impurity or not.
2. Check the possibility of measuring the bioavailability of the stated impurity during a biostudy.

From where I'm standing it seems not to make any sense. I can't find a reason why these questions are important in the biostudy point of view. In the scientific discussion of the innovator's drug it is stated that "From presented in vitro and in vivo data there are no indications of metabolism, which is expected due its polar and acidic properties" (regarding the inactive ion). But I'm required to present articles on this topic, but since no one cares about the inactive ion's pharmacokinetics there are no articles dealing with this very-very interesting question.

Further, I have not met any biostudies yet in which impurities of the inactive ion of the salt was measured. Is it because of lack of experience or am I right?

Many thanks in advance.

* I edited the original post because it came up in the third place when I Googled for the exact API and impurity which may be disadvantageous for me. Sorry.