Aim: Human 14C radiotracer studies provide information-rich data sets that enable informed decision making in clinical drug development. These studies are supported by liquid scintillation counting after conventional-sized 14C doses (50–200 μCi) or complex accelerator mass spectrometry (AMS) after microtracer-sized doses (∼0.1–1 μCi). Mid-infrared laser-based ‘cavity ring-down spectroscopy’ (CRDS) is an emerging platform for the sensitive quantitation of 14C tracers. Results & methodology: We compared the total 14C concentrations in plasma and urine samples from a microtracer study using both CRDS and AMS technology. The data were evaluated using statistical and pharmacokinetic modeling. Conclusion: The CRDS method closely reproduced the AMS method for total 14C concentrations. With optimization of the automated sample interface and further testing, it promises to be an accessible, robust system for pivotal microtracer investigations
Keywords:
- accelerator mass spectrometry
- ADME
- clinical
- CRDS
- laser
- mass balance
- microtracing
- pharmacokinetics
- tracer