Mucoadhesion and rheology characterization in topical semisolid formulations: An AQbD-driven case study

This study outlines a framework for developing a texture analyzer-based mucoadhesion method integrated with rheology analysis for evaluating ointment formulations. Using an Analytical Quality by Design (AQbD) approach, key sources of variability affecting critical method variables (CMVs) were identified. A Box-Behnken design evaluated applied force, contact time, and trigger force, with optimal conditions selected via response surface methodology (RSM) within the method operable design region (MODR). The final conditions—2 N applied force, 60 s contact time, and 0.05 N trigger force—ensured compliance with the analytical target profile (ATP). Incorporating mucin dispersion revealed significant rheological synergism, validating the optimized method. The framework adheres to ICH guidelines, demonstrating robust and reproducible performance.