Bioequivalence and Bioavailability Forum

Dear Yuvraj,

see WinNonlin's User Guide > Noncompartmental Analysis > NCA model selection.

The appropriate model is #202 (Constant Infusion).
WinNonlin has some problems in dealing with unit conversions (dose only). I suggest to give the dose in the mass unit of the concentration (in your case 20,000,000 ng) and the length of infusion in hours (5 min = 0.083 h), time of last dose 0.

❝ Secondary Parameters: T_max (min), [...] V_c (L), V_ss (L), CL (L/hr)

If you want to get T_max in minutes: Model options > Units. In the row 'Tmin, Tmax, Tlast, Tlag' change in the column 'Preferred' from 'hr' to 'min'. Note that units of these four parameters cannot be changed independently (in all versions including Phoenix WinNonlin 6). BTW, do you expect T_max to be different from 5 min? In the same tab change volumes from mL to L and clearance from mL/hr to L/hr.