Kinetics of R- and S-bupropion metabolism in human liver S9 fractions

Substrate and MetabolitesCLintCLint,Hafm,enantiomerbfmc
μl/min/mg S9 proteinl/h
 Total R-bupropion CLint11.9
 Total S-bupropion CLint59.2
  • a S9 fraction intrinsic clearance values were scaled to CLint,H using the scaling factor of 96.1 mg S9 protein/g liver (Watanabe et al., 2009). Assuming body weight of 70 kg and 21.4 g liver/kg body weight results in 1500 g liver weight (Ito and Houston, 2005). Protein binding in the incubations was negligible, and unbound fractions in the incubations were assumed to be 1.

  • b The fraction metabolized to each metabolite from the individual bupropion enantiomer (fm, enantiomer) calculated from CLint,H data.

  • c The fraction of racemic bupropion metabolized to the specific metabolite (fm).