title: High-performance liquid chromatographic determination of naltrexone in plasma of hemodialysis patients.
abstract: A simple, sensitive, selective and reliable reversed-phase high-performance liquid chromatographic (HPLC) method with UV detection is described for the determination of naltrexone in plasma samples. Naltrexone and the internal standard, naloxone, were isolated from plasma either with a liquid-liquid extraction method using ethyl acetate or with a solid-phase extraction method using Sep-Pack C18 cartridge before chromatography. The extracts were dried under a stream of nitrogen and the samples were reconstituted in the mobile phase, then 20 microL were injected on a Waters Symmetry C18 column (5 microm particle size, 4.6 x 150 mm). The mobile phase consisted of 0.06% triethylamine (pH 2.8)-acetonitrile (92:8, v/v) pumped at 1 mL/min. The peak-area ratio versus plasma concentration was linear over the range of 10-500 ng/mL and the detection limit was less than 8 ng/mL. Quantification was by ultra-violet detection at 204 nm. The present method was applied to the determination of the plasma concentration of naltrexone in dialyzed patients. Patients (n = 8) with severe generalized pruritus received 50 mg of naltrexone orally per day for 2 weeks. The variability in the therapeutic response in treated patients required plasma concentration investigations of this opioid antagonist.
authors.affiliation: Laboratoire de Pharmacologie, Pharmacocinétique et Pharmacie clinique, Faculté des Sciences Pharmaceutiques et Biologiques, Lille, France.
authors.forename: K
authors.initials: K
authors.lastname: Kambia
authors.forename: S
authors.initials: S
authors.lastname: Bah
authors.forename: T
authors.initials: T
authors.lastname: Dine
authors.forename: R
authors.initials: R
authors.lastname: Azar
authors.forename: P
authors.initials: P
authors.lastname: Odou
authors.forename: B
authors.initials: B
authors.lastname: Gressier
authors.forename: M
authors.initials: M
authors.lastname: Luyckx
authors.forename: C
authors.initials: C
authors.lastname: Brunet
authors.forename: L
authors.initials: L
authors.lastname: Ballester
authors.forename: M
authors.initials: M
authors.lastname: Cazin
authors.forename: J C
authors.initials: JC
authors.lastname: Cazin
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy; D009271:Naltrexone / Q000097:blood* / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000097:blood* / Q000627:therapeutic use; D011537:Pruritus / Q000188:drug therapy / Q000209:etiology; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D009292:Narcotic Antagonists; D009271:Naltrexone