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Published on: August 19, 2025
[Ultraviolet absorption of prescription sunblocks in Mexico]
Juan Pablo Castanedo-Cázares1, Bertha Torres-Alvarez, Cuauhtémoc Araujo-Andrade
1Departamento de Dermatología, Hospital Central "Ignacio Morones Prieto", Facultad de Medicina, Universidad Autónoma de San Luis, Potosí, México.
Background:
An appropriate sunscreen should provide high and broad ultraviolet protection both for the B and A range. The objective was quantify the ultraviolet absorption spectrum in sunscreens available for medical prescription, and analyze its relationship with the labeled Sun Protection Factor (SPF).
Material And Methods:
Thirty-nine sunscreens were analyzed in vitro using ultraviolet spectroscopy following exposure to simulated solar irradiation.
Results:
Fifty-six percent of sunscreens absorbed 90% or more of ultraviolet radiation. Seventy-five percent (n = 34) absorbed more than 95% of ultraviolet B radiation, and 46% (n = 18) more than 90% of ultraviolet A. There was no significant association between ultraviolet absorption and SPF.
Conclusion:
We were unable to estimate ultraviolet absorption only by its SPF. Protection differed considerably among products with similar SPF. Our study highlights regulation deficiencies in marketing practices of these products.
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