title: Quantitative high-performance liquid chromatographic method for pharmacokinetic studies of the potent mast cell inhibitor 4-(4'-hydroxyphenyl)amino-6,7-dimethoxyquinazoline (WHI-P131).
abstract: The novel quinazoline derivative 4-(4'-hydroxyphenyl)amino-6,7-dimethoxyquinazoline (WHI-P131) has recently been identified as a potent mast cell inhibitor capable of preventing IgE/antigen induced cutaneous as well as systemic fatal anaphylaxis in mice. Here we describe a sensitive high-performance liquid chromatography (HPLC)-based quantitative detection method for measurement of WHI-P131 levels in plasma as well as in target mast cells. The average extraction recovery for WHI-P131 was 88.4% for plasma and 75.7% for RBL-2H3 mast cell lysates. Good linearity (r>0.999) was observed throughout the concentration range of 0.1-20 microM in plasma and 0.01-5 nmol in 5 x 10(6) cells (0.5-238 microM per cell) for WHI-P131. Intra- and inter-assay variabilities were <7% and the lowest detection limit of WHI-P131 was 0.05 microM in plasma and 0.005 nmol in 5 million cells, respectively, at a signal-to-noise ratio of approximately 2. The practical utility of this new HPLC method was confirmed in a pilot pharmacokinetic study in BALB/c mice as well as in a cellular drug uptake and disposition study in RBL-2H3 mast cells. After intraperitoneal administration of a non-toxic 40 mg/kg bolus dose of WHI-P131, the estimated maximum plasma concentration was 92.7 microM, which is approximately 1-log higher than the effective in vitro mast cell inhibitory concentrations of WHI-P131. The drug absorption was rapid with an absorption half-life of only 2.9 min and the estimated time to reach the maximum plasma concentration was 8.3 min. WHI-P131 was cleared with an apparent systemic clearance rate of 2586 ml/h/kg and an elimination half-life of 1.8 h. An intracellular exposure level (AUC) of 55 microM x h was obtained after in vitro treatment of RBL-2H3 mast cells with WHI-P131 at a 33.6 microM final concentration in culture medium. The availability of the described quantitative HPLC detection method for WHI-P131 provides the basis for further development of WHI-P131 as an anti-allergic drug through detailed pharmacodynamic studies in preclinical animal models.
authors.affiliation: Department of Pharmaceutical Sciences, Hughes Institute, St. Paul, MN 55113, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Malaviya
authors.forename: H
authors.initials: H
authors.lastname: Chen
authors.forename: X P
authors.initials: XP
authors.lastname: Liu
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000493:pharmacokinetics* / Q000494:pharmacology; D019540:Area Under Curve; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006207:Half-Life; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010865:Pilot Projects; D011799:Quinazolines / Q000493:pharmacokinetics* / Q000494:pharmacology; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D018926:Anti-Allergic Agents; D011799:Quinazolines; C116180:WHI P131