Development and validation of an high performance liquid chromatography-tandem mass spectrometry method for the determination of imatinib in rat tissues.

An high performance liquid chromatography-tandem mass-spectrometry (HPLC-MS/MS) method was developed and validated for the determination in rat heart and liver of the tyrosine kinase inhibitor imatinib (IM), an anticancer drug approved for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. Extraction of the drug from tissues was performed by solvent extraction and the obtained extracts were analyzed by HPLC-MS/MS in selected reaction monitoring mode. The developed method was validated according to the criteria for bioanalytical method, showing good performances in terms of lower limit of quantification (LLOQ=0.02μgml(-1)), linearity (R(2)=0.998), repeatability (RSD<3%), reproducibility (RSD<13%) and recovery (RR>89%). The developed method was then applied to the analysis of heart and liver of rats treated with different doses of IM, with and without the simultaneous administration of carvedilol, a beta-blocking agent with cardioprotective effect, in order to evaluate tissue levels of the tyrosine kinase inhibitor. The obtained results revealed that the amount of IM in the rat heart was significantly affected by the administered dose, whereas carvedilol had no effect on IM concentrations. Thus, we have developed a method that allows the detection of IM traces in complex tissues such as the heart and liver and that may be proposed for the determination of the drug in other clinically relevant biological samples.