Developing Safe Organohydrogel Sunscreens Using Polyelectrolyte-Betaine Surfactant Complexes.

Area of Science:

• Materials Science
• Cosmetic Science
• Nanotechnology

Background:

• Oil-in-water emulsions are common in skincare but lack targeted delivery for sunscreen actives.
• Developing effective sunscreen delivery systems with enhanced UV absorption and minimal skin penetration remains a challenge.

Purpose of the Study:

• To create a novel organohydrogel sunscreen via physical cross-linking of a nanoemulsion.
• To investigate the UV-blocking capacity, water resistance, and skin penetration of the developed organohydrogel sunscreen.

Main Methods:

• Preparation of an oil-in-water nanoemulsion containing active sunscreen ingredients using coconut oil, lauramidopropyl betaine, and glycerol.
• Physical cross-linking of the nanoemulsion with chitosan under neutral pH conditions to form an organohydrogel.
• Evaluation of UV-blocking efficiency, water resistance, ease of removal, and skin penetration.

Main Results:

• The nanoemulsion effectively emulsified sunscreen ingredients, enhancing ultraviolet light absorption.
• A facile pH-triggered interfacial cross-linking transformed the nanoemulsion into a stable organohydrogel sunscreen.
• The organohydrogel sunscreen demonstrated efficient UV-blocking, water resistance, simple removal, and minimal skin penetration.

Conclusions:

• A scalable and facile method for producing organohydrogel sunscreens was established.
• The developed organohydrogel sunscreen is highly suitable for safe and effective application.
• This approach offers a promising pathway for advanced sunscreen formulations.