Rheological and Viscoelastic Analysis of Hybrid Formulations for Topical Application

Area of Science:

• Materials Science
• Pharmaceutical Sciences
• Biomedical Engineering

Background:

• Ultradeformable liposomes (UDL) are advanced delivery systems for both lipophilic and hydrophilic compounds.
• UDLs have significant applications in pharmaceutical and cosmetic topical formulations.
• Understanding formulation rheology is critical for predicting skin penetration and stability.

Purpose of the Study:

• To characterize the rheological and viscoelastic properties of hybrid topical formulations containing UDL.
• To assess the impact of UDL incorporation on formulation behavior.
• To evaluate the influence of temperature and aging on these properties.

Main Methods:

• Flow analysis using the Herschel-Bulkley model for non-Newtonian behavior.
• Identification of linear viscoelastic regions (LVR).
• Frequency sweep tests to determine G' and G″ moduli at varying temperatures and aging times.

Main Results:

• Formulations displayed non-Newtonian, pseudoplastic behavior, significantly altered by UDL incorporation.
• Predominantly elastic solid behavior (G' > G″) was observed across different conditions.
• Tan δ values confirmed the dominant solid-like characteristics over liquid behavior.

Conclusions:

• UDL incorporation influences the rheological profile of topical vehicles.
• The formulations exhibit robust viscoelastic properties, indicating suitability for topical applications.
• Careful selection of vehicles and formulation components is essential for optimizing UDL-based delivery systems.