Bioequivalence and Bioavailability Forum

Hi lizhao,

❝ We can still get a Test/Reference ratio for cortisol (not cortisol suppression) and then see if it is within (0.8, 1.25). Does it make sense?: confused:

That would be the theory yes, but it is a nightmare in practice. You will not find much about it in the literature, because companies don't like to publish it when they fail. That's a problem. But everytime 20 companies try to do something along those lines, 19 or so will fail.

Just to give you an idea: Cortisol measurements usually involve a blood sample. And even though we are all nice and calm when somebody takes a blood sample off of us, our corticol levels will react in an unpredictable manner. Depending on circumstances all this will be quite unrelated to the drug you are testing.... Then you can resort to urinary cortisol which is in another league of trouble.

Personally I would rather swim to the North pole, eat plutonium and have my appendix removed with a rusty fork than do any of this stuff. But that's just me, of course.

Finally, perhaps you are asking because you already have one or more failed PK studies. They failed because of something. Power, formulation, CRO, etc etc. Whatever it was, spend your money and time on fixing it and then redo your PK. If it requires a reformulation then so be it. A reformulation that is costly and which takes a lot of time may still be a much wiser decision.