Holmes and colleagues applied commercial sunscreen formulations that contain nano zinc oxide to human skin and tracked zinc. Zinc in the viable epidermis was not identified as nano zinc oxide particles. After 48 hours, zinc in the receptor solution is described as detected at a very low level, with the figure 0.07 µg/mL printed in that sentence. Zinc is the filter, not an impurity metal.
Key numbers
The receptor sentence prints 0.07 µg/mL after 48 hours. Comparisons of intact and impaired skin are given as fold changes in the text (about 3.5-fold in sweat and about 3-fold in CCT for zinc concentration within skin). Absolute concentrations that exist only in Table S1 or in an unread figure are not copied.
Methods (brief)
Just-accepted manuscript. Topical nano zinc oxide sunscreen, intact and impaired skin, receptor fluid at 48 hours. Analytical detail for particle versus dissolved zinc is the authors’ conclusion that viable-epidermis zinc was not nano zinc oxide.
Evidence fitness
The manuscript supports a dermal-penetration statement for zinc from mineral sunscreen. It does not support an impurity-metal occurrence table.
Limitations
Just-accepted text can differ from the version of record. Fold changes are not concentrations. The receptor value is a single low figure, not a distribution.
Related evidence
Update history
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