Tannic Acid as a Degradable Mucoadhesive Compound

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Effective mucoadhesive polymers are crucial for site-specific pharmaceutical delivery.
• Existing mucoadhesives like thiolated polymers have variable efficacy and require harsh synthesis conditions.
• Pyrogallol-based molecules show promise as adhesives, but their in vivo mucoadhesion is unproven.

Purpose of the Study:

• To investigate the mucoadhesive properties of a novel pyrogallol-rich formulation for potential pharmaceutical applications.
• To evaluate the efficacy and characteristics of tannic acid (TA) and poly(ethylene glycol) (PEG) composite (TAPE) for esophageal mucoadhesion.

Main Methods:

• Preparation of TAPE via a simple physical mixture of tannic acid (TA) and poly(ethylene glycol) (PEG).
• Assessment of TAPE's mucoadhesion duration on esophageal mucus layers after oral administration.
• Investigation of the pH-dependent mucoadhesion mechanism involving polyphenol-mucin interactions and ester linkage hydrolysis.

Main Results:

• TAPE demonstrated superior mucoadhesive properties, remaining on esophageal mucus for several hours (<8 h).
• Mucoadhesion was attributed to intermolecular interactions between TA's polyphenols and mucin.
• Adhesion strength showed pH dependency, being strong in neutral conditions and weak in acidic conditions.

Conclusions:

• TAPE, a physically blended TA-PEG composite, exhibits significant and long-lasting esophageal mucoadhesion.
• The pH-dependent mucoadhesion mechanism offers potential for controlled drug release applications.
• TAPE presents a promising candidate for developing advanced mucoadhesive drug delivery systems.