title: Liquid chromatographic assay for the antiviral nucleotide analogue tenofovir in plasma using derivatization with chloroacetaldehyde.
abstract: A sensitive and selective reversed-phase liquid chromatographic assay for tenofovir in human plasma has been developed and validated. Tenofovir was isolated from a 200 microl plasma sample using protein precipitation with trichloroacetic acid. The fluorescent 1,N(6)-etheno derivative is formed at 98 degrees C in the buffered extract with chloroacetaldehyde. This derivative was analysed using gradient ion-pair liquid chromatography and fluorescence detection at 254 nm for excitation and 425 nm for emission. In the evaluated concentration range (20-1000 ng/ml), the intra-day precision was 4% and the inter-day precision was 5-6%. An accuracy of between 97 and 110% was determined. The lower limit of quantification was 20 ng/ml with an inter-day precision of 11%, an intra-day precision of 12% and an accuracy of 103%. The assay is subject to interference from co-administered abacavir. The usefulness of the assay was demonstrated for samples obtained from an HIV-infected patient treated with tenofovir.
authors.affiliation: Utrecht University, Faculty of Pharmaceutical Sciences, Department of Biomedical Analysis, Division of Drug Toxicology, Sorbonnelaan 16, 3584 CA Utrecht, Netherlands. r.w.sparidans@pharm.uu.nl
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Sparidans
authors.forename: Kristel M L
authors.initials: KM
authors.lastname: Crommentuyn
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry*; D000225:Adenine / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D002853:Chromatography, Liquid / Q000379:methods*; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy; D006801:Humans; D063065:Organophosphonates; D009943:Organophosphorus Compounds / Q000097:blood* / Q000627:therapeutic use; D015203:Reproducibility of Results; D018894:Reverse Transcriptase Inhibitors / Q000097:blood* / Q000627:therapeutic use; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D000068698:Tenofovir
chemical_list: D063065:Organophosphonates; D009943:Organophosphorus Compounds; D018894:Reverse Transcriptase Inhibitors; D000068698:Tenofovir; C004656:chloroacetaldehyde; D000079:Acetaldehyde; D000225:Adenine