Zonula occludens toxin: an innovative method of oral drugs delivery

Conventional forms of administration of nonabsorbable drugs and peptides often rely on parenteral injection, because the intestinal epithelium represents a major barrier to the oral absorption of these therapeutical agents into the systemic circulation. Recently, a number of innovative drug-delivery approaches have been developed, including drug entrapment within small vesicles or the passage of the therapeutic molecules through the space between adjacent intestinal cells. This article reviews some of the most promising techniques currently available for oral delivery and their possible practical applications for the delivery of vaccines and drugs for the treatment of clinical conditions that require frequent, chronic parenteral administration.