title: Stereoselective method to quantify bupropion and its three major metabolites, hydroxybupropion, erythro-dihydrobupropion, and threo-dihydrobupropion using HPLC-MS/MS.
abstract: Bupropion metabolites formed via oxidation and reduction exhibit pharmacological activity, but little is known regarding their stereoselective disposition. A novel stereoselective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to separate and quantify enantiomers of bupropion, 4-hydroxybupropion, and erythro- and threo-dihydrobupropion. Liquid-liquid extraction was implemented to extract all analytes from 50 μL human plasma. Acetaminophen (APAP) was used as an internal standard. The analytes were separated on a Lux 3 μ Cellulose-3 250×4.6 mm column by methanol: acetonitrile: ammonium bicarbonate: ammonium hydroxide gradient elution and monitored using an ABSciex 5500 QTRAP triple-quadrupole mass spectrometer equipped with electrospray ionization probe in positive mode. Extraction efficiency for all analytes was ≥70%. The stability at a single non-extracted concentration for over 48 h at ambient temperature resulted in less than 9.8% variability for all analytes. The limit of quantification (LOQ) for enantiomers of bupropion and 4-hydroxybupropion was 0.3 ng/mL, while the LOQ for enantiomers of erythro- and threo-hydrobupropion was 0.15 ng/mL. The intra-day precision and accuracy estimates for enantiomers of bupropion and its metabolites ranged from 3.4% to 15.4% and from 80.6% to 97.8%, respectively, while the inter-day precision and accuracy ranged from 6.1% to 19.9% and from 88.5% to 99.9%, respectively. The current method was successfully implemented to determine the stereoselective pharmacokinetics of bupropion and its metabolites in 3 healthy volunteers administered a single 100mg oral dose of racemic bupropion. This novel, accurate, and precise HPLC-MS/MS method should enhance further research into bupropion stereoselective metabolism and drug interactions.
authors.affiliation: Indiana University School of Medicine, Indiana University Melvin and Bren Simon Cancer Center, RR208, 699 Riley Hospital Drive, Indianapolis, IN 46202, United States. Electronic address: argrove@iupui.edu.
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Masters
authors.affiliation: Phenomenex, 411 Madrid Avenue, Torrance, CA 90501, United States. Electronic address: MichaelMc@phenomenex.com.
authors.forename: Michael
authors.initials: M
authors.lastname: McCoy
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology, RR 208, 699 Riley Hospital Drive, Indianapolis, IN 46202, United States. Electronic address: drjones1@iu.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Jones
authors.affiliation: Department of Medicine, Division of Clinical Pharmacology, R2 402, 950 West Walnut Avenue, Indianapolis, IN 46202, United States. Electronic address: zdesta@iu.edu.
authors.forename: Zeruesenay
authors.initials: Z
authors.lastname: Desta
mesh_terms: D000293:Adolescent; D000328:Adult; D016642:Bupropion / Q000031:analogs & derivatives* / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D016642:Bupropion
keywords: 4-Hydroxybupropion; Bupropion; Enantiomers; HPLC–MS/MS; Stereoselective; erythro-Dihydrobupropion; threo-Dihydrobupropion