Title : Design and characterization of gum arabic buccal films for protein drug delivery
Abstract:
Oral mucoadhesive drug delivery systems, particularly buccal films, have gained increasing attention as promising alternatives to conventional dosage forms. These flexible systems adhere to the oral mucosa for extended periods without causing discomfort, thereby enhancing the absorption of poorly permeable drugs. In addition, they can protect sensitive biomolecules, such as peptides and proteins, from degradation while enabling controlled drug release. Buccal administration bypasses hepatic first-pass metabolism, resulting in rapid onset of action, improved bioavailability, and better patient compliance.
The present study focuses on the development and characterization of gum arabic (GA)-based mucoadhesive buccal films for protein delivery, using lyophilized egg white lysozyme as a model compound. The work addresses key challenges associated with oral macromolecule delivery, including enzymatic degradation, poor gastrointestinal stability, limited epithelial permeability, and extensive first-pass metabolism. Natural carbohydrate polymers, such as GA, are particularly attractive due to their biocompatibility, biodegradability, and safety.
Lysozyme-loaded GA films were prepared using a solvent casting method and optimized through a 2³ full factorial design. Spray-dried GA (Acacia senegal) was used as the film-forming polymer, while propylene glycol served as a plasticizer, citric acid as a cross-linker, and sorbitol as a stabilizer and sweetener. The films were characterized by evaluating biological activity, mechanical strength, mucoadhesion, moisture content, water uptake, disintegration time, as well as Raman, FT-IR, and thermal analyses, alongside drug release studies.
Results showed that GA is an effective multifunctional film-forming polymer. Lysozyme retained high biological activity (86–93%), indicating that the polymer matrix preserves protein structure during processing. Raman mapping confirmed uniform drug distribution. The films exhibited suitable mechanical strength (10–17 N) and strong mucoadhesion, ensuring proper handling and application. Rapid disintegration supports fast drug release initiation.
Thermal and spectroscopic analyses confirmed the absence of significant chemical interactions and demonstrated adequate stability. Dissolution studies revealed a biphasic release profile, with an initial burst followed by sustained release, attributed to hydration and swelling of the hydrophilic matrix.
Overall, this study provides the first systematic evaluation of GA as a film-forming biopolymer for protein-loaded buccal films. The findings highlight its potential as a safe and versatile excipient for stabilizing biopharmaceuticals and enabling controlled drug delivery, supporting the development of innovative mucosal drug delivery systems.
