Quantitative and pharmacokinetic analysis of naloxone in plasma using high-performance liquid chromatography with electrochemical detection and solid-phase extraction.
In this study we present a method for measuring naloxone in plasma after intravenous and oral administration of naloxone to humans, in order to study its pharmacokinetic profile. The method consists of a solid-phase extraction step followed by detection on a high-performance liquid chromatographic (HPLC) system equipped with an electrochemical dual-electrode detector. The extraction step employs cyanopropyl columns optimized for naloxone extraction to allow for elution of naloxone by the HPLC mobile phase; this eluate is then directly injected in the HPLC instrument. The HPLC system employs a radial compression phenyl column with a mobile phase containing 18% (v/v) acetonitrile and pentanesulfonic acid as ion-pairing agent; this system shows extraordinary high plate counts for naloxone. The detection limit is 3 ng (signal-to-noise ratio = 3) free naloxone per ml plasma. Following intravenous injection of 30 mg naloxone hydrochloride in two subjects, it was possible to determine the free naloxone concentration in the plasma for 8 h, more than four times the half-life of naloxone in plasma in humans.
Albeck
H
H
Hospital Laboratory for Addictive Diseases, Rockefeller University, New York, NY 10021.
Woodfield
S
S
Kreek
M J
MJ
D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D006801:Humans; D009270:Naloxone / Q000097:blood* / Q000493:pharmacokinetics; D009294:Narcotics / Q000032:analysis
D009294:Narcotics; D009270:Naloxone