NOVEL PARADIGMS IN MUCOADHESIVE DRUG DELIVERY SYSTEM

Mucoadhesion is a field of current interest in the design of drug delivery systems. Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Mucoadhesive drug delivery system may be designed to enable prolonged residence time of the dosage form at the site of application or absorption and facilitate an intimate contact of the dosage form with the underline absorption surface. Extending the residence time of a dosage form at a particular site and controlling the release of drug from the dosage form are useful especially for achieving controlled plasma level of the drug as well as improving bioavailability. Application of these dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The present review describes mucoadhesion, mucoadhesive polymers and use of these polymers in designing different types of mucoadhesive gastrointestinal, nasal, ocular, vaginal and rectal drug delivery systems. The research on mucoadhesives, however, is still in its early stage, and further advances need to be made for the successful translation of the concept into practical application in controlled drug delivery.