(T1230-02-09) Establishing Linear Viscoelastic Region and Gelation Dynamics in Anhydrous Intra Nasal Gel: Rheological Insights toward Optimized Patient-Centric Formulations

Purpose: Anhydrous nasal gels represent an emerging class of intranasal drug delivery systems, offering the dual benefits of improved residence time and enhanced mucosal adhesion. This study aimed to establish the rheological behavior, specifically the linear viscoelastic region (LVR) and gel point of a sprayable, anhydrous nasal gel system to inform its structural robustness and patient usability.

Methods: Oscillatory rheological measurements were performed to determine the LVR using frequency sweep tests, followed by gelation kinetics and mechanical strength assessments at physiologically relevant temperatures. The gel point, identified via the crossover of storage modulus (G') and loss modulus (G"), served as a critical indicator of microstructural transitions that directly impact sprayability and in situ performance.

Results: The formulation exhibited a well-defined LVR with minimal structural breakdown under moderate strain, suggesting excellent mechanical stability during actuation and post-administration. The identified gel point aligned with optimal viscoelastic balance, providing insight into microstructural integrity and formulation resilience under dynamic shear conditions. Additionally, the observation that the loss modulus and storage modulus exhibited a linear relationship without a crossover point during frequency sweep testing for a hydrogel indicated that the material predominantly behaved as a viscous liquid, with energy dissipation proportional to energy storage across the frequency range.

Conclusion: These rheological findings establish a robust framework for fine-tuning gel properties critical for nasal delivery—balancing mechanical strength, sprayability, and patient comfort. Understanding the viscoelastic and gelation characteristics ensures reliable dosing, prolonged mucosal retention, and enhanced patient adherence, making this approach pivotal in the rational design of next-generation intranasal therapeutics.


Equilibrium Flow Curve-Shear rate Vs Shear viscosity chart for Anhydrous Intranasal Gel


Equilibrium Flow Curve-Shear rate Vs Shear viscosity table for Anhydrous Intranasal Gel