摘要
Exenatide is the first approved glucagon-like peptide 1 receptor agonist subcutaneously or intramuscularly injected for the treatment of type 2 diabetes mellitus.Typical therapeutic plasma concentrations are in the low pg/mL range,therefore requiring ultra-sensitive quantification.To enable the accurate evaluation of pharmacokinetic studies,we established a UPLC-MS/MS assay with a lower limit of quantification(LLOQ)of 5 pg/mL(1.2 pM)using 200μL of plasma,validated acco rding to FDA's and EMA's pertinent guidelines.Exenatide was isolated from plasma with solid phase extraction utilizing anionexchange sorbent.Quantification was performed with positive electrospray ionization tandem mass spectrometry in the selected reaction monitoring mode.The calibrated concentration range of 5-10,000 pg/mL was linear showing co rrelation coefficients>0.99.Interday and intraday accuracy ranged from 97.5%to 105.4%with corre sponding precision of<10.9%.Accuracy at the LLOQ ranged from 93.0%to 102.5%with corresponding precision of<15.9%.Because of the validity of a 10-fold dilution QC(accuracy 111.2%),the assay is suitable for exenatide quantification up to 100,000 pg/mL.The ultra-sensitive assay's applicability was demonstrated by the quantification of exenatide plasma concentrations and pharmacokinetics after intravenous and nasal administration to beagle dogs.
基金
funded in part by the German Federal Ministry of Education and Research(BMBF,grant number 03VP03980)
supported in part by the Physician Scientist Program of the Faculty of Medicine of Heidelberg University。
