Overview on natural polymers: A promising pharmaceutical excipient in mucoadhesive drug delivery system

This review aims to compile the current literature with a perspective on the role of natural polymers or polysaccharides in mucoadhesive drug delivery systems. Natural polymers are basically polysaccharides, biocompatible, non-toxic, stable, and economical. Polymers play an important role as excipients in designing the dosage form and influence drug release without any side effects. Natural polymers are of growing interest in the utilization of mucosal drug delivery as a novel technique due to their ability to interact with the mucosal layer of the body, improve the effectiveness of the drug, and prolong the residence time of the dosage form at the site of absorption. The bioadhesive polymers can exert control over the rate and extent of drug release and are selected in the formulation of mucoadhesive drug delivery systems. This review article discusses several aspects of mucoadhesive drug delivery, including the mechanism of mucoadhesion, mucus layer, and mucoadhesive polymers, with special reference to natural-based polysaccharides, as well as their applications and roles in different formulations developed by using polysaccharides in various dosage forms.