Comparison of dermal absorption of zinc from different sunscreen formulations and differing UV exposure based on stable isotope tracing

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• 作者：Brian Gulson^a ; ^b ; ^{brian.gulson@mq.edu.au} ; Herbert Wong^a ; Michael Korsch^b ; Laura Gomez^a ; Philip Casey^c ; Maxine McCall^d ; Malcolm McCulloch^e ; Julie Trotter^e ; Jenny Stauber^f ; Gavin Greenoak^g
• 关键词：Human ; in vivo ; Nanoparticles ; Sunscreen ; Zinc isotopes ; Zinc oxide
• 刊名：Science of the Total Environment
• 出版年：2012
• 出版时间：15 March, 2012
• 年：2012
• 卷：420
• 期：Complete
• 页码：313-318
• 全文大小：1087 K

文摘

In a pilot study to determine if zinc (Zn) from zinc oxide nanoparticles in sunscreen can penetrate human skin in vivo, nanoparticles (~ 30 nm) of a stable isotope (52 % ⁶⁸Zn enrichment) were incorporated into an essentially phytochemical-based formulation and applied to the backs of 3 human subjects twice daily for 5 days during the Southern Hemisphere winter. Blood and urine were collected prior to application and at regular intervals and up to 50 days. As observed in a larger outdoor trial following this pilot study but with a different formulation and with UV exposure: values of ⁶⁸Zn in blood continued to increase beyond the 5 day application phase with the highest measurement at 14 days after the first application; variable amounts of the ⁶⁸Zn tracer were observed in urine; and the amounts of extra Zn added to blood were small and indicate very low levels of absorption (minimal estimate < 0.01 % of the applied dose) through the skin. Reasons for differences in absorption detected in the stable isotope trials and previous investigations include: the sensitivity of the stable isotope method; the duration of the investigations; the number of applications of sunscreen formulation; in vitro methods with excised skin; lack of measurement of blood and urine; no skin flexing; and lack of UV exposure.