Use of Caco-2 Cell Monolayers to Study Drug Absorption and Metabolism

The Caco-2 cell culture model is used to determine the absorption potentials of drug candidates and the transport and metabolism mechanisms of drugs and dietary chemicals. The Food and Drug Administration (FDA) recognized the model system as useful in classifying a compound’s absorption characteristics in the Biopharmaceutics Classification System. In addition to its usefulness as an absorption model, the Caco-2 cells are useful for studying the metabolism of drugs. More recently, they have been used to determine the efflux mechanisms of phase II conjugates of drugs and natural products. However, Caco-2 cells do not always express appropriate amounts of transporters or enzymes, which may introduce bias in the determination of their transport via a carriermediated process or their metabolism via a particular pathway. Additional genetic manipulation of the Caco-2 cells will be needed to further advance the utility of this model in the drug development process and to ultimately establish this model as the “gold standard” for studying intestinal disposition of drugs.