Mucoadhesive drug delivery systems have emerged as an advanced strategy to enhance drug residence time, bioavailability, and controlled release through various mucosal routes. These systems utilize natural and synthetic polymers capable of adhering to mucosal surfaces, thereby improving drug absorption and therapeutic efficiency. Buccal drug delivery is considered the most promising route due to its accessibility, high vascularization, and avoidance of first-pass metabolism. This review highlights the principles of mucoadhesion, mechanisms of adhesion, influencing factors, and various theories governing polymer-mucus interactions. It also discusses buccal drug delivery systems, formulation components, dosage forms, and evaluation techniques used to assess mucoadhesive performance. The challenges and future perspectives of mucoadhesive systems in pharmaceutical applications are also emphasized. Overall, mucoadhesive drug delivery systems offer a reliable approach for improving drug efficacy, especially for drugs with poor oral bioavailability.
