Development and evaluation of mucoadhesive buccal films for sustained release of glipizide using natural proteins.

Purpose: To address the challenges of frequent glipizide dosing, including its variable bioa-vailability and gastrointestinal side effects, this study developed and evaluated mucoadhesive buccal films using natural proteins (albumin, gelatin, casein) combined with HPMC E15 to achieve sustained drug delivery.

Methods: Nine formulations (F1-F9) were prepared using solvent casting technique and sys-tematically characterized. Comprehensive evaluations included: (1) drug-polymer compatibil-ity studies (FT-IR, DSC), (2) physicochemical characterization (thickness, weight uniformity, swelling index, moisture content, folding endurance, surface pH), (3) ex-vivo permeation studies through sheep buccal mucosa, and (4) stability assessments to determine film longevi-ty.

Results: Compatibility studies utilizing FT-IR and DSC confirmed no significant incompati-bility between glipizide and the excipients. Some of the important physicochemical character-istics recorded for different formulations were surface pH (6.6 - 6.8), folding endurance (72 - 184), moisture content (5.66 - 12.54%), thickness (0.171 - 0.236 mm), weight (0.150 - 0.238 mg), and swelling index (15.8% after 1 hour to 86.6% after 5 hours). Furthermore, neg-ligible variation was observed in these characteristics when stability studies were conducted after 3 months. The ex-vivo permeation studies demonstrated a sustained release of glipizide over 8 hours, with release percentages ranging from 80.94% to 90%. Formulation F6, which achieved an 8-hour release of 89.29%, was identified as optimal. Kinetic analysis revealed zero-order release kinetics for all formulations.

Conclusion:  The developed mucoadhesive buccal films exhibited excellent sustained-release properties, representing a significant improvement over conventional dosage forms. This in-novative delivery system shows strong potential for enhancing diabetes management through improved bioavailability and patient compliance, while minimizing gastrointestinal side effects.