Integrating automation and LC/MS for drug discovery bioanalysis.

A novel, integrated approach for automated sample handling in drug discovery bioanalysis is described. The process includes aspects of animal study design, biological sample collection, sample processing and high-throughput APILC/MS operating in under multiple reaction monitoring (MRM). A semi-automated 96-well liquid-liquid extraction technique for biological fluid sample preparation was developed and used in conjunction with the integrated sample-handling approach. One plate of samples could be prepared within 1.5 h compared with 4 h for a manual approach, and the resulting 96-well plate of extracts was directly compatible with the LC/MS. Feasibility studies for the development of the process included sample collection map generation and information management, sample collection formatting, evaluation of alternative dilution schemes for high-concentration samples, choice of biological fluid, and evaluating the capabilities of the two liquid-handling workstations. Numerous comparisons between the new approach and conventional sample-handling approaches gave equivalent drug-quantitation results for several example compounds. This new sampling process has approximately doubled the efficiency (as measured by studies assayed per month) of drug discovery bioanalysis in our laboratory. The approach was also used in conjunction with time-of-flight mass spectrometry instrumentation (LC/TOF/MS) to quantify and characterize the disposition of simultaneously dosed example drug compounds in the rat. Likely strategies for future automated sample preparation workstations are described.