Bioequivalence and Bioavailability Forum

❝ PK parameter calculations VD and CL values obtained from winNonlin were not matching with reference article

1. I have no experiences with this liposomal product, but I guess you don’t assume F=1 (otherwise why did you perform such a study?). If this is the case, infusion is not the correct NCA-model – use an extravasal model instead. Then you’ll get Vd/F and CL/F, where 0<F≤1 is unknown.
   
2. WinNonlin is notoriously bad in unit conversions. I guess you measured concentrations in ug/mL, right? It is a good idea to state the dose in the same mass-unit than the concentration, e.g., instead of 219 mg better use 219,000 ug.
   
3. For dose-normalizations you have two options:
   1. Give not the administered total dose for each subject but the dose per kg bodyweight. In the NCA-setup select Normalization and kg. Then you’ll get e.g. the clearance in mL/h/kg.
      
   2. Keep the current setup and transform the results (divide by the subject’s body weight). I’m not sure whether the unit of the result is correctly transformed in all version of WinNonlin. If not, change it (transformation/properties) accordingly.