Bioequivalence and Bioavailability Forum

Dear All,

I am carrying out ligand bind assay where the linearity range for detection of analyte is 400 – 32000 ng/mL. where 400 is anchor point and second standard concentration (STD2) 500 is LLOQ. Regression method used is Log-Log.

I have some queries regarding inclusion/exclusion of anchor point during analysis

1. If calibration curve is within acceptance criteria should I include anchor point?
   
2. If any calibration standard is not within acceptance criteria I should include anchor point.
   
3. If my LLOQ (500 ng/mL, STD 2) is not within acceptance criteria and if I include anchor point and then if it is within acceptance criteria then my LLOQ for that activity or batch will change from 500 to 400 ng/mL. Is it acceptable to regulatory?

Regards,
Ketan