Pranshu Tangri

Since, the last four decades, the concept of mucoadhesion has achieved a much valuable interest in the various fields of pharmaceutics. There are many advantages of mucoadhesive buccal drug delivery system that made this a novel drug delivery system for the local as well as systemic delivery of various drugs. The main advantage of this drug delivery system is that it prolongs the residence time of the dosage form at the site of application. Due to the high blood supply and relatively high permeability of the buccal mucosa, the buccal cavity is the best option for both local as well as systemic delivery of various drugs. The main prospect of writing this review article is to present comprehensive information related to mucoadhesion and mucoadhesive drug delivery systems. The article has highlighted all the aspects of mucoadhesive drug delivery systems which will be helpful for researches and academics. The article includes detailed information about mucosa- the anatomy and physiology, the mechanisms and theories related to mucoadhesion, evaluation parameters of mucoadhesive dosage forms, mucoadhesive polymers and novel approaches related to mucoadhesive drug delivery system. Drug actions can be improved by new drug delivery system, such as mucoadhesive system. This system remains in close contact with the absorption tissue, the mucous membrane, releasing the drug at the action site leading to improvement in both local and systemic effects. The potential merits and demerits of mucoadhesive drug delivery as well as that of the polymers are also discussed. It helps enhance the bioavailability through bypassing the first-pass metabolism effect. The mucosal surface better absorption and prolong resident time. Bioadhesion can be defined as the phenomenon of interfacial molecular attractive force in midst of the surface of the biological substrate and the natural or synthetic polymers, which allows the polymers to adhere to the biological surface for an extended period of time.

  Many therapeutic drugs are difficult to reach the central nervous system (CNS) from the systemic blood circulation because the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB) form a very effective barrier which prevents most molecules from passing through. BBB allows a selective entry of nutrients and minerals across it and limits the entry of foreign substances like drugs as well as neuropharmaceutical agents. To bypass BBB, drugs can be delivered through olfactory region for nose-to-brain targeting. . Intranasal administration of therapeutic agents (i.e., drug delivery via the nose) offers several advantages over oral, intravenous, and other routes of administration. Drugs can be rapidly absorbed through the large surface area of the nasal mucosa. Intranasal delivery is also non-invasive and essentially painless.  This review provides an overview of strategies to improve the drug delivery to the brain via the nasal mucosa and recent advances in the field.