title: Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of ARQ 501 (beta-lapachone) in plasma and tumors from nu/nu mouse xenografts.
abstract: A sensitive and specific LC-MS/MS method employing positive electrospray ionization for the determination of ARQ 501 (beta-lapachone) in (nu/nu) mouse plasma and tumor tissue is described. Samples were processed using protein precipitation with acetonitrile. A d6 analog of ARQ 501 was used as the internal standard (IS). The analytes were separated using a Zorbax SB8 column (30 mm x 2.1 mm i.d. 5 microm particle size) and analyzed in the multiple reaction monitoring (MRM) mode using mass transitions of 243>159 and 249>159 m/z for ARQ 501 and d6-ARQ 501, respectively. The lower limit of quantitation (LLOQ) for ARQ 501 was 3.0 ng/mL. The calibration curve was linear in the range of 3.0-2000 ng/mL with a correlation coefficient better than 0.99. Intra- and inter-batch precisions were within 8.4% for plasma and 11.8% for tumor samples. Accuracy expressed as percentage relative error (%R.E.) ranged from -9.0 to 7.7 for both plasma and tumor samples. Recovery was between 106 and 113% for both ARQ 501 and its d6 analog. Plasma pharmacokinetic data of ARQ 501 in mouse from intraperitoneal (IP) dosing at 60 mg/kg obtained using this validated method is presented along with tumor concentration data. The C(max), AUC(0-infinity), t(1/2), Cl/F, and V(d)/F were determined to be 4016 ng/mL, 4392 h ng/mL, 3.9 h, 13.7 L/h/kg, and 76.5 L/kg, respectively. Tumor tissue concentrations were in the range 1-2 microM for approximately 2 h post-dose.
authors.affiliation: Preclinical Development Department, ArQule Inc., 19 Presidential Way, Woburn, MA 01801, USA. savagero2005@yahoo.com
authors.forename: R E
authors.initials: RE
authors.lastname: Savage
authors.forename: T
authors.initials: T
authors.lastname: Hall
authors.forename: K
authors.initials: K
authors.lastname: Bresciano
authors.forename: J
authors.initials: J
authors.lastname: Bailey
authors.forename: M
authors.initials: M
authors.lastname: Starace
authors.forename: T C K
authors.initials: TC
authors.lastname: Chan
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D009285:Naphthoquinones / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D009374:Neoplasms, Experimental / Q000378:metabolism*; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014183:Transplantation, Heterologous
chemical_list: D009285:Naphthoquinones; C014638:beta-lapachone