Record number :
1470476
Title of article :
Determination of unbound fraction of imatinib and N-desmethyl imatinib, validation of an UPLC–MS/MS assay and ultrafiltration method
Author/Authors :
Arellano، نويسنده , , Cécile and Gandia، نويسنده , , Peggy and Lafont، نويسنده , , Thierry and Jongejan، نويسنده , , Rutchanna and Chatelut، نويسنده , , Etienne، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2012
Pages :
7
From page :
94
To page :
100
Abstract :
Imatinib is a small-molecule tyrosine kinase inhibitor with large inter-individual but low intra-individual pharmacokinetic variability with consistent concentration–efficacy and concentration–toxicity relationships. For these reasons imatinib therapeutic drug monitoring is based on total plasma concentrations. However, since a significant impact of unbound imatinib concentrations on clinical response and/or toxicity evaluation has been suggested, the quantification of free fraction of imatinib and its active metabolite are of interest for therapeutic monitoring. Hence a reliable method for both separation and assay of the free fraction is needed. Using plasma samples spiked with imatinib (from 1000 to 7500 ng/mL) and its metabolite (from 1000 to 2500 ng/mL), an ultrafiltration procedure and an UPLC assay which give reproductive values for unbound fractions of imatinib (mean 3.0 ± 1.0%) and metabolite N-desmethyl imatinib (3.6 ± 1.8%) have been developed. The validation of the analytical UPLC–MS/MS method associated to ultrafiltration for quantification of imatinib and N-desmethyl imatinib was reported. The LOQ was set at 10 ng/mL for imatinib and 20 ng/mL for N-desmethyl imatinib, intraday CV (%) ranged from 2.7 to 4.8% for imatinib and from 5.4 to 12.4% for N-desmethyl imatinib and interday CV (%) ranged from 5.6 to 6.5% for imatinib and from 5.4 to 16.1% for N-desmethyl imatinib. Methodological modifications were attempted to overcome non specific binding (NSB) on the ultrafiltration device. Two types of devices previously used for unbound determination of drugs were tested. Our results clearly showed that the methodology and the features of devices used for ultrafiltration could totally compromise the determination of unbound concentrations of a drug.
Keywords :
Imatinib , N-Desmethyl imatinib , Unbound fraction , Ultrafiltration , UPLC–MS/MS
Journal title :
Journal of Chromatography B
Serial Year :
2012
Link To Document :
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