Development and validation of a high-throughput assay for quantification of the proliferation inhibitor ABT-578 using LC/LC-MS/MS in blood and tissue samples.

We report here a specific, automated LC/LC-MS/MS assay for the quantification of ABT-578 in human and rabbit blood and rabbit tissues for drug-eluting stent development. After protein precipitation, samples were injected into the HPLC system and extracted online using a high flow of 5 mL/min. The extracts were then backflushed onto the analytic column. The [M+Na] of ABT-578 (m/z 988.6-->369.4) and its internal standard sirolimus (m/z 936.5-->409.3) were monitored. Extraction and analysis took 4 minutes. The assay was validated following the US Food & Drug Administration guidelines. Linearity was 0.025-25 ng/mL for most matrices. In human blood, interday accuracies were 81.8% (at 0.025 ng/mL), 91.0% (1 ng/mL), and 99.5% (50 ng/mL), and interday precisions were 10.7% (0.025 ng/mL), 3.0% (1 ng/mL), and 1.8% (50 ng/mL).