Determination of fluoxetine and its metabolite norfluoxetine in human liver microsomes by reversed-phase HPLC in vitro.
AIM
A high-performance liquid chromatography (HPLC) method was developed for the determination of fluoxetine (FLU) and its metabolite norfluoxetine (N-FLU) in human liver microsomes in vitro.


METHODS
An incubation buffer containing human liver microsomes, NADPH-generating system, and FLU, after termination of enzyme reaction and addition of nortriptyline (NOR) as internal standard (IS), was extracted with n-hexane/acetonitrile, and separated on a reversed-phase ODS column. Detection was achieved at 226 nm by ultraviolet detector (UV).


RESULTS
The limit of detection was 5 micrograms/L for both FLU and N-FLU. No potential interference was found. The method provides recoveries of up to 94%-104% and acceptable coefficients of variation were found for both within-run (< 7.8%) and day to day (< 9.1%) assays.


CONCLUSION
This method is rapid, sensitive, and simple for studying the metabolism of FLU and N-FLU.