RESUMO
OBJECTIVE:To establish an HPLC-CSP (chiral stationary phase) for the determination of plasma levels of enantiomers of fluoxetine. METHODS: Enantiomers of fluoxetine were separated on a Chirobiotic V column. The mobile phase consisted of methanol-acetic acid-triethylamine (100∶0.04∶0.04) with a flow rate of 1 mL?min-1. The detection wavelength was set at 226 nm.Clozapine was used as the internal standard. RESULTS: Under this chromatographic condition, both R-norfluoxetine and S-norfluoxetine had no interference on the enantiomers of fluoxetine and the internal standard. The calibration curve was linear in the range of 8.1～432 ng?mL-1(r=0.999 8) for R-enantiomer and in the range of 10.8～432 ng?mL-1 (r=0.999 2) for S-enantiomer. The relative recovery of R-fluoxetine and S-fluoxetine in plasma were 97.2%～101.9% and 98.7%～102.2%, respectively. RSD of intraday and interday ranged from 2.6% to 5.3% and from 7.7% to 8.9% for R-fluoxetine, and from 2.1% to 6.7% and from 8.0% to 10.6% for S-fuoxetine, respectively. CONCLUSION: The method is simple, reliable and sensitive, and applicable for the determination and pharmacokinetic study of the enantiomers of fluoxetine in plasma.