Development and in vitro evaluation of buccoadhesive tablets using a new model substrate for bioadhesion measures:...

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Mucoadhesive drug delivery systems enhance oral drug absorption and prolong residence time.
• Gelatin and cellulose derivatives (HPC, HPMC, NaCMC) are common polymers for mucoadhesive tablet formulation.

Purpose of the Study:

• To formulate and characterize mucoadhesive tablets using gelatin combined with different cellulose derivatives.
• To evaluate the in vitro bioadhesive properties and drug release mechanisms of these formulations.

Main Methods:

• Mucoadhesive tablets were prepared by direct compression using gelatin/HPC, gelatin/HPMC, and gelatin/NaCMC blends.
• In vitro bioadhesion was assessed using a tensile tester with polypropylene and eggshell membranes.
• Drug release kinetics were studied for metronidazole and benzydamine.

Main Results:

• Bioadhesive properties were significantly influenced by the substrate used for evaluation (polypropylene vs. biological membrane).
• Eggshell membrane provided more reliable bioadhesion data compared to polypropylene.
• All formulations exhibited an anomalous (non-Fickian) erosion-diffusion release mechanism.

Conclusions:

• Gelatin-based mucoadhesive tablets with HPC, HPMC, and NaCMC are feasible for oral drug delivery.
• The choice of substrate is critical for accurate in vitro bioadhesion assessment.
• The observed erosion-diffusion release mechanism is characteristic of swellable mucoadhesive systems.