March 2012 in “Korean Journal of Microscopy” Quantum dot nanoparticles can penetrate skin and reach sebocytes through hair follicles.
106 citations
,
June 1990 in “Journal of Investigative Dermatology”
162 citations
,
August 2005 in “The journal of investigative dermatology/Journal of investigative dermatology” The new "differential stripping" method effectively measures how much substance gets into hair follicles.
15 citations
,
October 2020 in “European journal of pharmaceutics and biopharmaceutics” Caffeine penetrates skin quickly through open hair follicles, but less through closed ones, with levels becoming equal after 22 hours.
82 citations
,
May 2009 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Caffeine penetrates human skin in lab tests similarly to real-life conditions, but actual skin use is still essential for accurate results.
82 citations
,
January 2002 in “Journal of drug targeting” Drugs penetrate scalp skin better than abdominal skin, with scalp hair follicles aiding in higher drug delivery.
67 citations
,
January 2012 in “Biological and Pharmaceutical Bulletin” Nanoparticles don't penetrate intact skin but can enter through pores or damaged skin.
3 citations
,
April 2015 in “International research journal of pharmacy” Gentamicin penetrates pig skin better through open hair follicles than blocked ones.
2 citations
,
November 2025 in “Pharmaceutics” Moderately lipophilic dyes penetrate skin deeply, while highly hydrophobic or lipophilic dyes stay on the surface.
Folate salts penetrate skin well and improve wound healing, suggesting potential for skin treatments.
36 citations
,
July 2004 in “Journal of Controlled Release” The dye quickly penetrates hair follicles, mainly through the gap, not the surrounding skin.
128 citations
,
March 2016 in “Advanced Pharmaceutical Bulletin” Smaller nanoparticles penetrate skin better, especially through hair follicles.
90 citations
,
November 2014 in “Journal of Biomedical Optics” Silver nanoparticles can penetrate porcine skin up to about 15.6 μm, possibly through hair follicles.
21 citations
,
November 2020 in “European Journal of Pharmaceutics and Biopharmaceutics” Low-frequency skin massage helps nanoparticles penetrate hair follicles better.
19 citations
,
December 2013 in “European journal of pharmaceutics and biopharmaceutics” Encapsulated Garcinia mangostana extract in cream penetrates skin better than other forms.
1 citations
,
November 2004 in “International Journal of Cosmetic Science” External agents penetrate skin more easily in areas with fewer lipids, especially through hair follicles.
264 citations
,
January 2008 in “Journal of biomedical optics” Zinc oxide nanoparticles in sunscreen do not penetrate deep into the skin.
69 citations
,
January 2002 in “Journal of biomedical optics” Dyes can penetrate human skin and hair follicles up to 1.2 mm deep and the sebaceous gland can store dye; Indocyanine Green lotion was made for safe dyeing and monitoring.
54 citations
,
October 2002 in “Journal of controlled release” Medium lipophilic substances penetrate skin best, and adding ethanol can increase delivery to hair follicles.
29 citations
,
September 2024 in “AAPS PharmSciTech” Transcutol® helps drugs penetrate the skin more effectively in various formulations.
15 citations
,
February 2023 in “Colloids and surfaces. B, Biointerfaces” Smaller curcumin nanocrystals penetrate skin better, but additives and particle size affect absorption and accumulation.
14 citations
,
November 2019 in “Materials” Diamond nanoparticles can penetrate skin and reach hair follicles, useful for imaging applications.
April 2021 in “bioRxiv (Cold Spring Harbor Laboratory)” Topical folates can penetrate skin and enhance wound healing.
45 citations
,
August 1954 in “Experimental Biology and Medicine” Vitamin A penetrates guinea pig skin quickly in alcohol, affects skin thickness, but doesn't impact hair growth.
122 citations
,
April 2011 in “European Journal of Pharmaceutics and Biopharmaceutics” Particles around 100 nm can penetrate and stay in hair follicles without passing through healthy skin, making them safe for use in topical products and useful for targeted drug delivery.
40 citations
,
March 2019 in “Pharmaceutical development and technology” Smaller particles of the drug carrier penetrated skin better, with 300 nm size being best for targeting hair follicles.
8 citations
,
April 2012 in “Laser Physics Letters” Antiseptic particles penetrate deeper into hair follicles than non-antiseptic ones.
July 2022 in “International Journal of Applied Pharmaceutics” The optimized caffeine formula improved hair growth and penetrated all skin layers.
1 citations
,
January 2025 in “Molecules” More research is needed to effectively measure how well GHK–Cu in liposomes penetrates the skin.
60 citations
,
August 1969 in “British Journal of Dermatology” Germicides mostly stay on the skin's surface, but some penetrate deeper depending on the product used.