TLDR The dye quickly penetrates hair follicles, mainly through the gap, not the surrounding skin.
The study utilized on-line confocal laser scanning microscopy (CLSM) to visualize the diffusion of a lipophilic dye, Bodipy® FL C5, into the hair follicle of fresh, unfixed human scalp skin. This method allowed for real-time imaging every 30 minutes over 16 hours, revealing that the dye penetrated quickly into the hair follicle gap and stained the cuticle, primarily from the gap rather than the surrounding epidermis. The technique overcame limitations of increased scattering and absorption in deeper skin layers and provided a new tool for monitoring distribution profiles in skin layers, aiding in the optimization of drug formulations for local delivery to the pilosebaceous unit.
405 citations
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January 2004 in “Journal of Investigative Dermatology” Hair follicle size and distribution vary significantly across different body sites.
44 citations
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April 2003 in “European journal of pharmaceutical sciences” Lipophilic dyes accumulate more in hair follicles when delivered with surfactant-propylene glycol solutions.
54 citations
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October 2002 in “Journal of controlled release” Medium lipophilic substances penetrate skin best, and adding ethanol can increase delivery to hair follicles.
82 citations
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January 2002 in “Journal of drug targeting” Drugs penetrate scalp skin better than abdominal skin, with scalp hair follicles aiding in higher drug delivery.
44 citations
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April 2003 in “European journal of pharmaceutical sciences” Lipophilic dyes accumulate more in hair follicles when delivered with surfactant-propylene glycol solutions.
1 citations
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July 2005 in “Drugs and the pharmaceutical sciences” Targeting drugs to hair follicles can treat skin conditions, but reaching deep follicle areas is hard and needs more research.
54 citations
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October 2002 in “Journal of controlled release” Medium lipophilic substances penetrate skin best, and adding ethanol can increase delivery to hair follicles.
4 citations
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March 2013 in “InTech eBooks” Confocal Laser Scanning Microscopy (CLSM) is a useful tool for studying how drugs interact with skin and diagnosing skin disorders, despite some limitations.
February 2024 in “Pharmaceutical research” Hair follicles affect how well small molecules can pass through the skin, and this varies depending on the molecule's features.
