Biocompatible lipid-based liquid crystals and emulsions.

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Biocompatible Formulations

Background:

• Glycerol trioleate/sodium oleate/water ternary systems are investigated for biocompatible applications.
• Understanding their phase behavior is crucial for formulation development in cosmetics, food, and pharmaceuticals.

Purpose of the Study:

• To characterize the phase behavior and internal structure of the glycerol trioleate/sodium oleate/water ternary system.
• To evaluate the stability and potential applications of emulsion regions within this system.

Main Methods:

• Optical microscopy was used to visualize the system's structure.
• Nuclear Magnetic Resonance (NMR) methods, including self-diffusion measurements of water and oil, were employed.
• Ternary phase diagrams were constructed to map different regions.

Main Results:

• The ternary diagram features extensive monophasic and biphasic regions, including a lamellar phase coexisting with isotropic phases.
• A significant emulsion region with small oil droplets dispersed in a lamellar phase was identified.
• NMR self-diffusion data provided insights into the internal structure and droplet sizing.
• Oil droplet size distribution followed a highly polydisperse log-normal distribution.
• Samples within the liquid crystalline phase region exhibited negligible changes in droplet size and no phase separation after months of storage at 25°C.

Conclusions:

• The glycerol trioleate/sodium oleate/water system forms stable emulsions stabilized by a liquid crystalline phase.
• These stable, biocompatible formulations are promising for cosmetic, food, and pharmaceutical applications.
• The liquid crystalline phase significantly enhances the long-term stability of the emulsions, preventing phase separation.