Background: The growing need to use sunscreens is a concrete reality, and it is associated with the increase in the population's awareness of the ultraviolet (UV) radiation damage. Inorganic UV filters promote the formation of particles/pigments film over the skin surface, reflecting, dispersing, and absorbing the radiation. Investigations of this class of filters demonstrate the emergence of alternative ingredients and new technologies.
Aims and methods: In this review, we presented potential candidates for alternative UV inorganic filters, such as hydroxyapatite, cerium dioxide, and hydrotalcite.
Results: Specialized literature identified hydroxyapatite and cerium dioxide as actives with good performances, with a broad spectrum of absorption against UV radiation. Both of them were considered safe against degradation and skin erythema formation. Inorganic compounds as an alternative to circumvent degradation problems of organic UV filters containing PABA were also analyzed, with hydrotalcite having a good performance in improving the performance of classic ingredients, bypassing photoinstability, and improving safety, in addition to preventing skin irritability.
Conclusion: Further investigations of these ingredients and interactions with sunscreen formulations are necessary to overall explore their safety and efficacy, encouraging future researches for more inorganic UV filters.
Keywords: UV filter; delivery/vectorization/penetration; formulation/stability; inorganic UV filter; safety; sunscreen.
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