Targeted delivery of drugs to the gastrointestinal tract

The oral route is attractive for drug administration because it is associated with patient acceptability, less stringent production conditions, and lower costs. However, gastrointestinal destruction of labile molecules and low levels of absorption generally render oral delivery of peptides and proteins ineffective. Several strategies have the potential to enhance the efficacy of orally administered drugs. Bioadhesion is an approach for increasing interaction between drugs and the mucosae. Bioadhesive systems can be nonspecific, achieving adhesion via mechanical processes or specific systems that recognize receptors on epithelial cells. Lectins are one group of specific bioadhesives with many suitable properties for targeting of cells in the gastrointestinal tract (GIT). This review assesses the potential of lectins in the delivery of drugs and vaccines to the GIT.