Formulating gels for decreased mucociliary transport using rheologic properties: polyacrylic acids

Area of Science:

• Pharmacology
• Biomaterials Science
• Rheology

Background:

• Mucociliary clearance is a crucial defense mechanism in the respiratory tract.
• Bioadhesive polymers are explored for drug delivery applications, but their impact on mucociliary clearance needs characterization.

Purpose of the Study:

• To determine the specific rheologic properties of polyacrylic acid gels required for optimal reduction of mucociliary clearance.
• To assess the in vitro mucociliary transport of polycarbophil and carbopol polymers.

Main Methods:

• In vitro assessment of mucociliary transport using bovine tracheal explants.
• Measurement of polymer gel viscoelastic properties using controlled stress rheometry in the presence of mucus.
• Correlation analysis between rheologic parameters and mucociliary transport rate (MTR).

Main Results:

• Apparent viscosity (eta) and complex modulus (G*) were identified as key parameters for predicting the effect of polyacrylic acid formulations on MTR.
• A specific range of eta and G* values was found to effectively reduce MTR while maintaining suitable fluidity for intranasal administration.
• Correlations established for polycarbophil gels were used to identify other polyacrylic acid gels with desirable mucociliary clearance properties.

Conclusions:

• In vitro rheologic testing can effectively guide the optimization of polyacrylic acid formulations for reduced mucociliary clearance.
• Specific rheologic profiles (eta and G*) are critical for developing effective intranasal mucoadhesive drug delivery systems.
• The findings provide a framework for designing polyacrylic acid-based formulations with controlled mucoadhesive properties and optimized drug delivery kinetics.