ABSTRACT
Topical delivery to the oral cavity is used to treat localized conditions of the mouth, such as aphthous ulcers, fungal infections, and periodontal disease. However, the oral cavity can also be used to achieve the systemic delivery of a drug, i.e., oral transmucosal delivery. As described in Chapter 7, the peroral (i.e., via the gastrointestinal [GI] tract) route remains the preferred route for the administration of therapeutic agents because of its low cost, ease of administration and high level of patient compliance. However, this route of administration also has disadvantages, such as hepatic rst-pass metabolism and acidic and enzymatic degradation within the GI tract, which often prohibits its use for certain drug classes, including peptides and proteins. Consequently, other absorptive mucosa (i.e., the mucosal linings of the nasal, rectal, vaginal, ocular, and oral cavity) are often considered as an alternative site for drug administration. One such alternative route is oral transmucosal drug delivery, which offers many distinct advantages over peroral administration for systemic drug delivery, including the avoidance of the hepatic rst-pass effect and presystemic elimination within the GI tract.
