A review on orally disintegrating films (ODFs) made from natural polymers such as pullulan, maltodextrin, starch, and others

In recent years, orally disintegrating films (ODFs) have been studied as alternative ways for drug administration. They can easily be applied into the mouth and quickly disintegrate, releasing the drug with no need of water ingestion and enabling absorption through the oral mucosa. The ODFs matrices are typically composed of hydrophilic polymers, in which the natural polymers are highlighted since they are polymers extracted from natural sources, non-toxic, biocompatible, biodegradable, and have favorable properties for this application. Besides that, natural polymers such as polysaccharides and proteins can be applied either alone or blended with other synthetic, semi-synthetic, or natural polymers to achieve better mechanical and mucoadhesive properties and fast disintegration. In this review, we analyzed ODFs developed using natural polymers or blends involving natural polymers, such as maltodextrin, pullulan, starch, gelatin, collagen, alginate, chitosan, pectin, and others, to overview the recent publications and discuss how natural polymers can influence ODFs properties.