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

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.

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.

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.

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.