Site-Specific Drug Delivery to the Gastrointestinal Tract
There are many available routes for the administration of therapeutic agents, as denoted by the FDA’s recognition of over 100 different options for getting a drug into the body [1]. The oral (“per os” or PO) dosing of pharmaceutical products has a long and rich history in health care. This route of administering medications has several notable advantages, including the fact that it is relatively simple, it requires no additional equipment for patient administration (unlike injectable or inhaled agents), it is usually the least expensive option for both the manufacturer and the patient, and it is typically the safest route of getting a drug into the body (requiring no puncturing of body surfaces or membranes and the corresponding increased risk of disease transmission). Because of these and other advantages, the majority of currently used pharmaceutical agents are formulated and given as oral dosage forms. PO administration is also the preferred route for the treatment of diseases of the gastrointestinal tract, such as peptic/duodenal ulcer and inflammatory bowel diseases, because this technique puts the therapeutic agent at or near the desired site of action. In addition, the GI tract represents the major portal of entry of infectious agents into the body and the site at which most organisms exert their patho physiologic effects [2]. Due to this fact, one of the best ways to protect against infection would be the oral administration of vaccines to stimulate strong specific immunity in the gastrointestinal tract and other mucosal sites [3].