The transporters of intestinal tract and techniques applied to evaluate interactions between drugs and transporters

Most drug products on the global pharmaceutical market are administered orally. The absorption of oral drug in the intestine is an important factor to determine the drug bioavailability. There are many intestinal transporters expressed on the small intestine and the transporters can be classified into two major families, SLC family and ABC family. They mediate drug absorption, distribution, excretion and drug–drug interaction. Understanding the transport mechanism can improve the effectivity and safety of drug and guide clinical rational use of drugs. The roles of drug transporters can be assessed in vitro and in vivo, using techniques spanning from cellular expression systems to gene knockout animals. The purposes of this article were to introduce the main transporters in the intestinal tract, to explain the transport mechanism and to compare the limitations and applications of techniques used to evaluate interactions of drugs and transporters.