Microneedles allow transdermal delivery of skin-impermeable drugs by creating transient micropores in the skin through which drug can diffuse into the systemic circulation. Micropore lifetime after microneedle application may be a limiting step for a successful microneedle delivery strategy, and this has not been broadly studied in skin of color. In this work we hypothesized that race/ethnicity and/or skin characteristics may influence micropore lifetime after solid microneedle treatment. We explored this hypothesis in a sample of 111 healthy human subjects in six racial/ethnic categories (self-identified by the subjects). Our data demonstrate for the first time that micropore lifetime differs in human subjects of different ethnic/racial backgrounds, with longer micropore lifetime observed in skin of color. Our findings suggest that objectively measured skin color, rather than self-identified ethnic/racial group, may be a better predictor of micropore lifetime.
Describe the uses of microneedles for drug delivery purposes, including current and future applications
Understand the importance of epidermal micropores, and micropore closure kinetics, for a successful microneedle delivery strategy
Understand the differences in objectively measured epidermal characteristics in various human skin types
Understand how micropore lifetime can be predicted using a simple modeling approach
Quantify micropore closure time among human subjects of different racial/ethnic backgrounds and correlate with objective measurements of skin color, rather than self-identified ethnic/racial group