GASTRORETENTIVE DRUG DELIVERY SYSTEM: STOMACH SPECIFIC MUCOADHESIVE TABLET

Abstract

The current article focuses on the principles of mucoadhesive drug delivery systems based on adhesion to biological surfaces that are covered by mucus. Bioadhesion can be defined as the process by which a natural or a synthetic polymer can adhere to a biological substrate. When the biological substrate is a mucosal layer then the phenomena is known as mucoadhesion. Drug actions can be improved by developing new drug delivery systems, such as the mucoadhesive system. These systems remain in close contact with the absorption tissue, the mucous membrane, releasing the drug at the action site leading to a bioavailability increase and both local and systemic effect. Mucoadhesion is defined as the ability of material adheres to biological tissue for an extended period of time. Mucoadhesive dosage forms extend from the simple oral mucosal delivery to the nasal, vaginal, ocular and rectal drug delivery systems. The success and degree of mucoadhesion bonding is influenced by various polymer-based properties. Evaluation of such mucoadhesive formulations has transgressed from first-generation charged hydrophilic polymer net-works to more specific second generation systems based on lectin, Thiol and various other adhesive functional groups. Various theories are consider like Electronic theory, Wetting theory, Absorption theory, Fracture theory in mucoadhesion. Various In vitro and In vivo tests carried out for determination of mucoadhesion.