Formulation of mucoadhesive buccal films using pregelatinized cassava starch phthalate as a film-forming polymer

Objective: This study aimed to compare the characteristics of four buccal films formulated with phthalylated cassava starch and their drug delivery potentials. Methods: An alternative to conventional (oral) drug administration is to administer drugs in a buccal film; however, the required dosage must be dissolved in a film-forming polymer with suitable mechanical and mucoadhesive characteristics. Previous studies have produced excipients by physically and chemically modifying starch, such as by completely pregelatinization and phthalylation it in an aqueous medium under alkaline conditions (pH 8-10). This produced a pregelatinized cassava starch phthalate (PCSPh) powder with a high degree of substitution (0.0541±0.0019), thus giving it different physical, chemical, and functional characteristics than unphthalated PCS. Results: PCSPh in 4.5% and 6% (w/w) concentrations was used as excipients for producing four formulations of buccal film. One film had the most suitable characteristics, with an ex vivo mucoadhesion time of 57.1±20.3 min, tensile strength of 0.84±0.02 N/mm², and a more rapid drug release profile than two of the other film types produced. Our tests also revealed that the best film tended to not change physically when moistened (percentage moisture absorption was 139% and moisture loss was 65%). Conclusion: Thus, we predict that PCSPh could be adequately formulated to provide mucoadhesive buccal films with an appropriate drug release profile.