Local delivery of imiquimod in hamsters using mucoadhesive films and their residence time in human patients

Objective. To investigate the ability of mucoadhesive films to locally deliver an immune response modifier (imiquimod) to oral mucosa. Study Design. After determining the residence time of films in hamster cheek pouches, drug-loaded films and commercially available imiquimod cream were tested for localization of drug in mucosal tissue. The residence time of drug-free films at different locations was also tested in humans. Results. Mucoadhesive films delivered imiquimod to the buccal mucosa with no measureable amounts in blood. In contrast, although the cream formulation resulted in higher tissue levels, it also led to significant systemic distribution of imiquimod. In humans, the films resided on tissue for up to 4 hours, increasing in the order of tongue < cheek < gingiva. Conclusion. Preclinical findings of localized imiquimod delivery in animals and residence in humans support future investigations of the mucoadhesive system in controlled clinical trials for treating oral precancerous lesions.