Sensitivity test for indicators solution

Dear sir,
I am using the redy made solution of indicators (eg. Merck Phenolphthalein indicator 1.0%) for titration and assay analysis.
my question is that, it is regulatory requirement to do the sensitivity test for the indicator solution or it is acceptable to use redy made indicator solution???

please suggest me.

The auditor may ask for the sensitivity test for the indicator, you should do it.

But sir can you please help me out that how the sensitivity test of indicator will perform? And in Ph eur where it will be mention?

In general chapters of indicators and reagents the procedure will be there

Yes , You can use but COA necessary