With respect to drug absorption, transport and metabolism, Ussing chambers are recognized as the gold standard in vitro method. By allowing investigations in living tissues, our ADME/DMPK assays models can accurately predict drug behavior in humans.
Oral bioavailability is dependent not only on liver metabolism but also, critically, on absorption through the gastrointestinal tract, where passive and active absorption and metabolism via brush-border enzymes are key. Alternative in vitro methods, such as Caco-2 cells or intestinal microsomes, are useful for either permeability or metabolism experiments, but not for both. This is because they don't express the correct levels of transporters or enzymes; only human fresh tissues reflect the true biology.
Moreover, as many animal species used in preclinical species differ significantly in their patterns of gastrointestinal permeability or metabolism, using human fresh gastrointestinal tissue avoids species differences when predicting oral bioavailability.
Diagram showing the typical setup of an ADME/DMPK experiment in our Ussing Chamber model.