Solid emulsion gel as a novel construct for topical applications: synthesis, morphology and mechanical properties

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Hydrogels and emulsions are widely used in biomedical applications.
• Developing novel composite materials with tunable properties is crucial for advanced therapies.

Purpose of the Study:

• To synthesize and characterize novel solid emulsion gels (SEGs) with varying oil content.
• To investigate the swelling, mechanical, and skin hydration properties of SEGs.
• To explore the potential of SEGs for transdermal drug delivery.

Main Methods:

• Polycondensation reaction between poly(ethylene glycol) and protein-stabilized emulsions.
• Characterization of swelling behavior, morphology, and mechanical properties.
• In vivo skin hydration and mechanical testing.

Main Results:

• SEGs synthesized with oil volume fractions from 0-50%.
• Swelling degree decreased with increasing oil content.
• Increased oil content reduced stiffness but enhanced extensibility (Young's moduli 9-15 kPa, elongation at break 120-220%).
• Demonstrated positive skin hydration effects.

Conclusions:

• SEGs exhibit a unique combination of hydrogel and emulsion characteristics.
• Mechanical properties can be tuned by adjusting oil content, following a rule of elasticity mixture.
• SEGs show promise for biomedical applications, particularly in transdermal drug delivery.