title: Subnanogram-concentration measurement of buprenorphine in human plasma by electron-capture capillary gas chromatography: application to pharmacokinetics of sublingual buprenorphine.
abstract: We describe a sensitive and specific method for the measurement of buprenorphine in human plasma. The method involves a structural analog as an internal calibrator, careful control of pH during sample extraction to maximize drug recovery, and back-extraction into acid followed by reextraction to eliminate endogenous interferences. After evaporation, sample residues are derivatized with heptafluorobutyric anhydride and analyzed by separation on a fused-silica polymethylsiloxane capillary column and electron-capture detection. Calibration curves were linear in the ranges 0.1-2.0 micrograms/L and 2.0-20 micrograms/L, with within-run CVs of 9.7% at 0.1 microgram/L to 5.0% at 20 micrograms/L, and total CVs of 15.9% at 0.1 microgram/L to 6.5% at 10 micrograms/L. The limit of quantification was 0.1 microgram/L. The method was utilized in studies to determine the absolute bioavailability of sublingual doses of 2 mg of buprenorphine in 1 mL of 300 mL/L ethanol and the bioequivalence of sublingual 8-mg tablet and 300 mL/L ethanol solution formulations.
authors.affiliation: Department of Psychiatry, University of California, San Francisco 94143, USA.
authors.forename: E T
authors.initials: ET
authors.lastname: Everhart
authors.forename: P
authors.initials: P
authors.lastname: Cheung
authors.forename: P
authors.initials: P
authors.lastname: Shwonek
authors.forename: K
authors.initials: K
authors.lastname: Zabel
authors.forename: E C
authors.initials: EC
authors.lastname: Tisdale
authors.forename: P
authors.initials: P
authors.lastname: Jacob
authors.forename: J
authors.initials: J
authors.lastname: Mendelson
authors.forename: R T
authors.initials: RT
authors.lastname: Jones
mesh_terms: D000286:Administration, Sublingual; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D001682:Biological Availability; D002047:Buprenorphine / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002849:Chromatography, Gas; D004355:Drug Stability; D006801:Humans; D007275:Injections, Intravenous; D012680:Sensitivity and Specificity
chemical_list: D000701:Analgesics, Opioid; D002047:Buprenorphine