The research explores the development and evaluation of mucoadhesive buccal films for the sustained release of diclofenac sodium, a widely used non-steroidal anti-inflammatory drug (NSAID) for pain relief. Mucoadhesive buccal films are an innovative drug delivery system designed to adhere to the mucous membrane in the oral cavity, enabling the controlled release of drugs directly into the bloodstream, bypassing first-pass metabolism and improving therapeutic outcomes. These films provide sustained release, localized action, and improved compliance, making them more convenient for patients. Mucus membranes, which are moist surfaces lining body cavities, are the main components of mucus gels. The wetting theory applies to mucoadhesion, which involves the release of mucus from the mucosal surface into the bloodstream. The study aims to develop a more efficient and effective method for the controlled release of diclofenac sodium, a potent anti-inflammatory and analgesic drug.