ABSTRACT
Bioadhesive drug delivery systems have been widely studied in the past two decades. Primarily, the application of bioadhesion to drug delivery involves the process of mucoadhesion, a “wet-stick” adhesion requiring, primarily, spreading of the mucoadhesive on a mucin-coated epithelium, followed by interpenetration of polymer chains between the hydrated delivery system and mucin. An alternative mechanism can involve the use of specific bioadhesive molecules, notably lectins, primarily for oral drug delivery applications. The most notable applications of mucoadhesive systems to date remain those involving accessible epithelia, such as in ocular, nasal, buccal, rectal, or intravaginal drug delivery systems. The ancillary effects of certain mucoadhesive polymers, such as polycations, on promoting drug penetration of epithelial tissues, may be increasingly important in the future, particularly for the transmucosal delivery of therapeutic peptides and other biomolecules.
