Population model analysis of chiral inversion and degradation of bupropion enantiomers, and application to enantiomer specific fraction unbound determination in rat plasma and brain

•Chiral inversion was faster than enantiomer degradation in plasma and brain.•Chiral inversion was faster in plasma (three to five-fold) than brain or buffer.•A model was developed to quantify parallel inversion and degradation kinetics.•Model approach provided reliable enantiomer binding estimates in brain and plasma.