Tannin microcapsules for synergy-enhanced sunscreen formulations

Salicylate and benzoate sunscreen agents have been encapsulated by the green, fast and robust ultrasound technique in tannin microcapsules (TMCs). The generated TMCs, obtained without use of cross linking agents, were fully characterised, including encapsulation efficiencies with respect to the encapsulated actives. Release kinetics of TMCs have been studied mimicking skin conditions. Body cream base samples containing specific concentrations of microcapsules filled with sunscreen actives were prepared and showed synergistic effects in terms of UV-protection abilities generated by the interplay between sunscreen actives and natural tannin polyphenols. The synergistic effect exerted by the tannin and the controlled active release allows to reduce the amount of synthetic sunscreens needed, and does thus contribute to the development of more sustainable and environmentally benign UV-protection systems.