Rheological Assessment for Determining Form Stability of Wound Dressings

The classification of wound care products as form-stable dressings remains challenging due to the lack of objective and quantitative, material-science-based criteria. This study introduces a rheological testing framework to determine form stability of wound dressing materials. Using dynamic, oscillatory shear rheology, we evaluated the viscoelastic properties and responses of two tube-dispensed model dressings and compared them to those of honey, a high-viscosity liquid used in wound ointments. Measurements of the material storage modulus, loss modulus and phase angle demonstrated that both model dressings exhibit predominantly solid-like responses, confirming their classification as form-stable wound dressings despite being applied from a tube. The notably low phase angles of these dressings indicate structural integrity, which is essential for the mechanical protection of wounds; honey exhibited a liquid response and a high phase angle, without structural integrity. The reported laboratory method and findings support the implementation of rheological classification as a standardised, objective and quantitative approach for wound care product categorisation, independent of the packaging or application mode. Importantly, this study establishes a foundation for a material-science-driven classification framework, with implications for informed clinical decision-making and reimbursement policies.