Bioadhesives are natural polymeric materials that act as adhesives. Bioadhesion is the adhesion between two materials where at least one of the material is of biological origin. In mucoadhesion, the material of biological origin is the mucous membrane. In this PowerPoint presentation, we will discuss the various theories of mucoadhesion. Further, we will discuss in-depth the factors involved in Buccal Drug Delivery Systems like the structure of oral mucosa, buccal environment, mechanism of permeation and basic formulation components. This presentation was created by me to discuss with my pharmaceutical colleagues about various concepts of mucoadhesion and buccal drug delivery. However, the concepts remain same hence people from any Lifesciences background can refer to this.