Quantitation of dolastatin-10 using HPLC/electrospray ionization mass spectrometry: application in a phase I clinical trial.

Journal Article

A highly sensitive and specific assay for the quantitation of the anticancer agent dolastatin-10 (DOL-10) in human plasma is described. The method was based on the use of electrospray ionization-high-performance liquid chromatography/mass spectrometry (ESP-LC/MS). The analytical procedure involved extraction of plasma samples containing DOL-10 and the internal standard (DOL-15) with n-butyl chloride, which was then evaporated under nitrogen. The residue was dissolved in 50 microl mobile phase and 10 microl was subjected to ESP-LC/MS analysis using a C18 microbore column. A linear gradient using water/acetonitrile was used to keep the retention times of the analytes of interest under 5 min. The method exhibited a linear range from 0.005 to 50 ng/ml with a lower limit of quantitation (LLQ) at 0.005 ng/ml. Absolute recoveries of extracted samples in the 85-90% range were obtained. The method's accuracy (< or =5% relative error) and precision (< or =10% CV) were well within industry standards. The analytical procedure was applied to extract DOL-10 metabolites from samples obtained following incubation of the drug with an activated S9 rat liver preparation. Two metabolic products were detected and were tentatively identified as a N-demethyl-DOL-10 and hydroxy-DOL-10. Structural assignments were made based on the fragmentation patterns obtained using the electrospray source to produce collision-induced dissociation (CID). The method was also applied to the measurement of DOL-10 in the plasma of patients treated with this drug. Preliminary investigation of the pharmacokinetics suggested that drug distribution and elimination may be best described by a three-compartment model with t1/2alpha = 0.087 h, t1/2beta = 0.69 h and t1/2gamma = 8.0 h. Plasma clearance was 3.7 l/h per m2.

Full Text

Duke Authors

Cited Authors

  • Garteiz, DA; Madden, T; Beck, DE; Huie, WR; McManus, KT; Abbruzzese, JL; Chen, W; Newman, RA

Published Date

  • January 1998

Published In

Volume / Issue

  • 41 / 4

Start / End Page

  • 299 - 306

PubMed ID

  • 9488599

Electronic International Standard Serial Number (EISSN)

  • 1432-0843

International Standard Serial Number (ISSN)

  • 0344-5704

Digital Object Identifier (DOI)

  • 10.1007/s002800050743

Language

  • eng