Analysis of naltrexone and its metabolite 6-beta-naltrexol in serum with high-performance liquid chromatography

• Main Authors: Heinälä Pekka, Lahti Tuuli, Sinclair David, Ariniemi Kari, Lillsunde Pirjo, Alho Hannu
• Format: Article
• Language: English
• Published: BMC 2012-08-01
• Series: BMC Research Notes
• Subjects: Naltrexone; 6-β-naltrexol; High-performance liquid chromatography; Alcoholism
• Online Access: http://www.biomedcentral.com/1756-0500/5/439
• ISSN: 1756-0500

<p>Abstract</p> <p>Background</p> <p>Naltrexone has been proven to be an effective treatment option for the treatment of alcohol dependency. In this article we introduce a reliable and simple method developed for the simultaneous determination of naltrexone and 6-β-naltrexol in human serum by using high-performance liquid chromatography (HPLC).</p> <p>Findings</p> <p>Liquid-liquid extraction with butyl acetate from basic solutions (pH 9) was chosen for extraction with nalorphine as an internal standard (IS). Analytes were back-extracted from organic solvent into perchloric acid. The acid extract was chromatographed by HPLC with a reverse-phase ODS-column and electrochemical detector. The mobile phase was a NaH₂PO₄-solution with acetonitrile as an organic modifier and octanesulphonic acid and tetraethylammonium hydrogen sulphate as ion-pair reagents. The recovery of the extraction method was 48% for naltrexone and 75% for 6-β-naltrexol. The limit of quantification was 5.0 ng/ml for naltrexone and 1.0 ng/ml for 6-β-naltrexol. The analysed concentrations of naltrexone differed from the theoretic concentrations by 0.7 to 2.3% and those of 6-β-naltrexol by 2.6%. The relative standard deviation of within-day assay was from 0.9 to 5.7% for naltrexone and from 0.8 to 4.2% for 6-β-naltrexol; for the between-day assay it was 5.7% and 4.2%, respectively.</p> <p>Conclusions</p> <p>Our results indicate that the developed method is suitable for determination of naltrexone and 6-β-naltrexol in human serum.</p>