TLDR Medium lipophilic substances penetrate skin best, and adding ethanol can increase delivery to hair follicles.
In a study from 2002, researchers investigated the penetration and distribution of three fluorescent lipophilic probes (Oregon Green® 488, Bodipy® FL C5, and Bodipy® 564/570 C5) in human scalp skin using confocal laser scanning microscopy. After an 18-hour penetration period, the skin was imaged, and relative accumulation values were calculated. The findings showed that Bodipy® FL C5, with medium lipophilicity, had the highest overall penetration, while Bodipy® 564/570 C5, with high lipophilicity, had the lowest penetration but the highest relative accumulation within the hair follicle. Additionally, adding 30% ethanol to the donor phase increased follicular delivery for the substance with low lipophilicity. The study concluded that drug delivery to hair follicles can be enhanced by increasing the lipophilicity of the drug and optimizing the donor phase composition, but the specific transport route to the follicles remains unclear. The number of human subjects or skin samples used in the study was not specified.
182 citations
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January 2000 in “Drug Development Research” Ethosomal carriers improve drug delivery through the skin better than traditional methods.
37 citations
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January 1997 in “Journal of Pharmaceutical Sciences” Hairless rats absorb substances through their skin more easily than hairy rats.
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January 1994 in “Skin Pharmacology and Physiology” Hair follicles and glands significantly increase steroid absorption in skin.
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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.
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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.
Plant-based compounds can improve wound dressings and skin medication delivery.
January 2017 in “Journal of Investigative Dermatology Symposium Proceedings” The 2015 Hair Research Congress concluded that stem cells, maraviroc, and simvastatin could potentially treat Alopecia Areata, topical minoxidil, finasteride, and steroids could treat Frontal Fibrosing Alopecia, and PTGDR2 antagonists could also treat alopecia. They also found that low-level light therapy could help with hair loss, a robotic device could assist in hair extraction, and nutrition could aid hair growth. They suggested that Alopecia Areata is an inflammatory disorder, not a single disease, indicating a need for personalized treatments.
