The oral route is one of the most important routes for local and systemic drug delivery, as it has a large surface, high permeability, and rich blood supply. Mouth dissolving films, are now becoming more popular than fast-dissolving tablets. The films are designed to disintegrate quickly when they come into touch with a surface that contains water, such the tongue. This allows the consumer to consume the product without the use of water. It can boost patient compliance and provide you a marketing advantage. The polymer used in mouth dissolving films is crucial to their quick dissolution and disintegration. The polymer must be non-toxic, non-irritating, flavorless, and simple to use. Natural and synthetic polymers are the two types of polymers that are employed. Natural polymers used in formulation of film include chitosan, gaur gum, xanthan gum, soy polysaccharide, gellan gum, locust bean gum, maltodextrin, and rosin. Hydroxypropyl cellulose, polyvinyl pyrrolidone, Hydroxypropyl Methylcellulose, Polyethylene Oxide, and Polyvinyl Alcohol are synthetic polymers that are frequently used to make films. The current overview gives a description of the numerous polymers that are utilized to make films that dissolve in the mouth.

Hydrogels are the three-dimensional hydrophilic network which is crosslinked physically or chemically. Hydrogels are also called as hydrophilic gels because they absorb considerate amount of water. The characteristic properties of hydrogels are swelling, mechanical properties, biodegradable, elasticity, biocompatible, easy to modify, flexibility, etc. They are classified based on source, polymeric composition, biodegradability, configuration, cross linking, physical appearance, chemical charges, and drug release. Hydrogels can be synthesized from natural, synthetic, semisynthetic polymers via physical, chemical crosslinking, through grafting, coacervation and polymerization. The hydrogels are useful in daily life and their major applications are drug delivery to oral cavity, GI tract, rectal, ocular, protein, subcutaneous, transdermal, controlled drug delivery, preparation of contact lenses, wound healing, tissue engineering, biosensing, bacterial culture preparation, and various other fields like agriculture, electronics, cosmetics, gene delivery, perfume delivery, regenerative medicine, plastic surgery, sealant adhesive, watering beads for plant and water purification.