title: High-throughput determination of atrasentan in human plasma by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.
abstract: Atrasentan (A-147627) is an endothelin antagonist receptor being developed at Abbott Laboratories for the treatment of prostate cancer. A quick and sensitive method for the determination of atrasentan in human plasma has been developed and validated using high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. A dual-column, single mass spectrometer system is used to provide a reliable and routine means to increase sample throughput. The analytical method involves liquid-liquid extraction and internal standard (A-166790). The plasma samples and internal standard are acidified with 0.3 M hydrochloric acid prior to being extracted into 1:1 (v/v) hexanes--methyl t-butyl ether. The organic extract was evaporated to dryness using heated nitrogen stream and reconstituted with mobile phase. Atrasentan and internal standard were separated with no interference in a Zorbax SB-C(18) analytical column with 2.1 x 50 mm, 5 microm, and a Zorbax C(8) guard column using a mobile phase consisting of 50:50 (v:v) acetonitrile--0.05 M ammonium acetate, pH 4.5, at a flow rate of 0.30 mL/min to provide 4 min chromatograms. For a 250 microL plasma sample volume, the limit of quantitation was approximately 0.3 ng/mL. The calibration was linear from 0.30 to 98.0 ng/mL (r(2) > 0.995). A significant advantage of the method is the ability to employ parallel HPLC separations with detection by a single MS/MS system to provide sensitivity and selectivity sufficient to achieve robust analytical results with a lower limit of quantitation of 0.30 ng/mL and high throughput.
authors.affiliation: Drug Analysis Department, Abbott Laboratories, R46W, AP9-1, 100 Abbott Park Rd, Abbott Park, IL 60064, USA. perry.wang@abbott.com
authors.forename: Perry G
authors.initials: PG
authors.lastname: Wang
authors.forename: Jack
authors.initials: J
authors.lastname: Wei
authors.forename: Min
authors.initials: M
authors.lastname: Chang
authors.forename: Tawakol
authors.initials: T
authors.lastname: El-Shourbagy
mesh_terms: D000970:Antineoplastic Agents / Q000097:blood* / Q000737:chemistry; D000077868:Atrasentan; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D019332:Endothelin-1 / Q000037:antagonists & inhibitors; D006801:Humans; D011759:Pyrrolidines / Q000097:blood* / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods* / Q000592:standards
chemical_list: D000970:Antineoplastic Agents; D019332:Endothelin-1; D011759:Pyrrolidines; D000077868:Atrasentan