Bioadhesive or Mucoadhesive Drug Delivery System: A Potential Alternative to Conventional Therapy

The term bioadhesive describes materials that bind to biological substrates, such as mucosal membranes and in bioadhesive drug delivery systems, the term bioadhesion is used to describe the bonding or adhesion between a synthetic or natural polymer and soft tissues such as epithelial cells. The bioadhesive drug delivery formulation highlights the fact that readily accessible sites are utilized with the eye, oral cavity and vegina being targeted. The GI tract and the nasal cavity have also been extensively examined as a site for bioadhesive drug delivery. The term mucoadhesion is the subgroup of bioadhesion and in the mucoadhesion formulation attaches with the mucus membrane. The mucoadhesion can be defined as the adhesion between the two materials in which one is biological material and other one is polymeric materials with the help of interfacial forces to increase the residence time. Over the past few decades, mucosal drug delivery has received a great deal of attention. The mucoadhesion drug delivery system is better than the traditional drug delivery systems. Mucoadhesion is a useful strategy for drug delivery systems, such as tablets, patches, gels, liposomes, micro/nanoparticles, nanosuspensions, microemulsions and colloidal dispersions. The mucoadhesion bypasses the first pass metabolism and used for localized delivery of biomolecules such as peptides, proteins and oligonucleotides. Mucoadhesion drug delivery system engages much attention due to their benefits such as prolong retention time, fast uptake and increased bioavailability of active substance. Application of 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 mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, theories of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, mucoadhesive polymers and herbal drugs. Keywords: Bioadhesive, bioadhesive drug delivery, Mucoadhesion, Patches, Herbal drugs