title: Development and validation of a semi-automated assay for the highly sensitive quantification of Biolimus A9 in human whole blood using high-performance liquid chromatography-tandem mass spectrometry.
abstract: Drug-eluting stents are sustained-release intra-coronary devices that are usually coated with a few hundred micrograms of drug. Measuring the drugs that are released over weeks in order to assess human pharmacokinetics is a challenge that requires assays with high sensitivity. We developed and validated a semi-automated LC-MS/MS assay for the quantification of Biolimus A9, a proliferation signal inhibitor that was specifically developed for coating on drug-eluting stents in human EDTA blood. The only manual step was the addition of a zinc sulfate/methanol protein precipitation solution which included the internal standard. Samples were injected into the HPLC and extracted online. The assay had the following performance characteristics: range of reliable response 0.01-100 ng/mL (r(2)>0.99), inter-day accuracy (0.033 ng/mL): 111.7%, and inter-day precision: 8.6%. There was no ion suppression, matrix interferences or carry-over. Extracted samples were stable in the autosampler at +4 degrees C for at least 24 h and could undergo three freeze-thaw cycles. The assay, with a lower limit of detection of 333 fg/mL and a lower limit of quantitation of 10 pg/mL, was sufficiently sensitive and robust for quantifying Biolimus A9 in clinical trials after i.v. injection and after stent implantation.
authors.affiliation: Clinical Research & Development, Department of Anesthesiology, University of Colorado Denver, Aurora, CO 80045-7503, USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Clavijo
authors.forename: Tobin
authors.initials: T
authors.lastname: Strom
authors.forename: Vanessa
authors.initials: V
authors.lastname: Moll
authors.forename: Ronald
authors.initials: R
authors.lastname: Betts
authors.forename: Yan Ling
authors.initials: YL
authors.lastname: Zhang
authors.forename: Uwe
authors.initials: U
authors.lastname: Christians
authors.forename: Jamie
authors.initials: J
authors.lastname: Bendrick-Peart
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D054855:Drug-Eluting Stents; D006801:Humans; D015203:Reproducibility of Results; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000097:blood; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C518022:umirolimus; D020123:Sirolimus