Bioequivalence and Bioavailability Forum

Dear Harish!

❝ In my example, 12 hours is not the last sampling timepoint. The following concentrations were above LOQ. In such cases, do we need to mention this timepoint as 12,BLOQ or 12,0 in WinNonlin?

First of all I would suggest to perfom a blinded plausibility review of analytical data. You must have an SOP in place which describes when and why a value may be requested for reanalysis based on PK grounds. Only if the value was confirmed as BQL, I (!) would keep it as 12,BQL and set WinNonlin's options to deal with Missing values accordingly:
Tools > Options... > Models > Default Parameter Options (NCA calculation method) >
Linear Trapezoidal (Linear/Log Interpolation)

❝ Since 12,BLOQ and 12,0 are treated differently by WinNonlin, which one of these would be the right way of data handling in WinNonlin?

After dosing we know only one thing for sure: the concentration is not zero!
OK, to stay with this example of a dose of 10 mg of a drug with a molecular mass of 200 g/mol and a half life of 2 hours on the average only 1 molecule is left in the systemic circulation after 129 hours...

❝ Alternately, is it right to totally skip this timepoint entry in WinNonlin?

IMHO no - you do have a result: BQL.

See also these two related earliers threads initiated by Ratnakar and DLabes: some collegues have other opinions!