Bioequivalence and Bioavailability Forum

Dear Fourm

I have face with problem. I am analyst of LC-MS/MS

1) Ibandronate's analytical sample preparation method is derivatization with SPE. I used Ibandronate's isotope as a international standard(IS). And its IS area deviation are little bit high about 30% in every batch. My problem is that there is IS ared diviation area in QC sample. Is this QC sample is fail? or Pass ? In our SOP, eventhough there is IS area deviation in QC sample, we do not reanalysis. But FDA donot agree this SOP. they feel that is is also deal with sample.

I want to know your experience in your study.

2) Is there any guidline of IS area deviation in sample batch. If you have any journal or guidline, Please let me know.