Microdialysis can reveal pharmacokinetics and physiological changes in tissue.
By Benjamin Kuzma, Long Island University, and Nimita Dave, AbbVie
Microdialysis is a powerful semi-invasive technique that enables continuous measurement of local drug, metabolites, or neurochemical concentration changes over time in the extracellular space in vivo. The technique of microdialysis employs perfusion of an isotonic physiological liquid through the microdialysis probe. The analyte(s) of interest diffuses through a semi-permeable membrane of the probe, implanted at the site of interest, into the perfusate. Pharmacological activity depends on the concentration of the drug at the target site. Plasma pharmacokinetic profiles, which are more commonly analyzed, are only surrogates in our efforts to understand exposure-response relationships. The biggest advantage of microdialysis is that it measures the unbound concentrations of the analyte(s) at the target tissue site over a period of time. Recent advances in bioanalytical techniques such as liquid chromatography-tandem mass spectrometry have further increased the versatility of this technique. Microdialysis is extensively applied in the brain, skin, adipose tissue, and muscles.