title: Determination of laquinimod in plasma by coupled-column liquid chromatography with ultraviolet absorbance detection.
abstract: Laquinimod is an immunomodulator that is currently in clinical trials. For pharmacokinetic and toxicokinetic studies in animals and humans a sensitive and accurate bioanalytical method was required. In this paper a bioanalytical method for the determination of laquinimod by liquid chromatography is described. After a protein precipitation step the plasma sample was injected onto a coupled-column HPLC system. After further purification from macromolecules on a short restricted access material C(18) column the analyte was transferred to a reversed-phase C(18) analytical column and separated from interfering substances. The analyte was detected by UV detection. The method was validated with respect to linearity, selectivity, precision, accuracy, limit of quantitation, limit of detection, recovery and stability. The limit of quantitation was 0.75 micromol/L, the intermediate precision was 1.8-3.6% (C.V.) and the accuracy was 97.7-114.7%. In conclusion, the method was found to perform well and is suitable for use in pharmacokinetic and toxicokinetic studies.
authors.affiliation: Active Biotech Research AB, Box 724, S-220 07 Lund, Sweden. karin.edman@lrc.activebiotech.com
authors.forename: Karin
authors.initials: K
authors.lastname: Edman
authors.forename: Birgitta
authors.initials: B
authors.lastname: Eriksson
authors.forename: Leif
authors.initials: L
authors.lastname: Svensson
authors.forename: Per Olov
authors.initials: PO
authors.lastname: Gunnarsson
mesh_terms: D000276:Adjuvants, Immunologic / Q000097:blood*; D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D006801:Humans; D051379:Mice; D015363:Quinolones / Q000097:blood*; D051381:Rats; D015203:Reproducibility of Results; D013048:Specimen Handling; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D000276:Adjuvants, Immunologic; D015363:Quinolones; C476223:laquinimod