P78-2 Automatic Quantification Analysis of Amrubicin and Amrubicinol Using LC-MS/MS

Amrubicin (AMR) is an active drug in patients with relapsed or refractory small cell lung cancer. Severe neutropenia is often observed, and in some patients, subsequent treatment delay and/or dose reduction is often required. We clarified the relationship between the absolute neutrophil count-time profiles and the pharmacokinetic properties of AMR and its active metabolite amrubicinol (AMR-OH) previously, and a therapeutic drug monitoring (TDM) study is ongoing. We have developed and validated a fully-automated analytical method for the measurement of AMR and AMR-OH concentrations in human plasma using LC-MS/MS which can be applied simply to TDM. Extraction Procedures, including protein precipitation, extraction and collected extract, were performed automatically by the automated sample preparation system (CLAM-2030, Shimadzu) connected to a triple quadrupole mass spectrometer (LCMS-8050, Shimadzu). The collected extract was injected and separated using an octadecylsilane column on reversed phase mode. The method was validated in terms of selectivity, linearity, accuracy, and precision according to Guidance for Industry, Bioanalytical Method Validation by FDA. The total run time was 5.2 min. The method showed satisfactory results in selectivity for AMR and AMR-OH on testing for interference using 6 blank plasma samples. The method was linear in the range of 5-1000 ng/mL for AMR and AMR-OH, with correlation coefficient values of 0.999 and 0.999, respectively. The accuracy and precision were -10.7∼8.0%, and 2.1∼7.0% for AMR, and -9.8∼5.0% and 1.9∼5.0% for AMR-OH. These results met the criteria of the validation guidance. This fully-automated method is able to quantify human plasma AMR and AMR-OH concentration. Once samples are loaded into the automated sample preparation system, no further human intervention is required. This could be applied to a clinical pharmacokinetic study in lung cancer patients.