Chapter 1: INTRODUCTION Mucoadhesion is due to strong interaction between chemical groups of polymers and mucosal lining of the tissues. Mucin, the principal component of mucus, is responsible for the gel-like properties of the mucus. Mucin, basically glycoproteins, which consist of a protein core covalently attached over its length with carbohydrate chains. Mucus helps in protecting the tissues from chemical and mechanical damages using its lubrication properties. Mucoadhesive interactions achieved mainly by hydrogen bonding of carboxyl, hydroxyl and other hydrogen bonding groups between glycoprotein and mucin.1 Transmucosal delivery of therapeutic agents attained much attention compared to other methods of drug delivery in recent days. Transmucosal …show more content…
However, typical controlled release formulations are limited by insufficient retention in the stomach. The strategies which are developed to overcome this includes, (a) low density floating DDS b) high density DDS retains in the lower part of the stomach, (c) mucoadhesive delivery systems, (d) swellable which unfolds in the stomach to hinder its escape through the pyloric sphincter. An alternative strategy which combines bioadhesion with the ability to expand by swelling, would be beneficial. This may overcome challenges for oral mucoadhesive systems such as harsh environment of the stomach, which, due to its low pH, results in an inactivation of a wide range of drugs. And also, it prevents the low residence time of the drug at the site of absorption due to wash out effect in the GI tract due to the intestinal motility. Mucoadhesive controlled drug delivery systems are very beneficial, since they provide a controlled drug release over time and localize the drug to a specific site of the body. The prolonged residence time of the drug in the body is believed to prolong duration of