316 citations,
June 2004 in “The journal of investigative dermatology/Journal of investigative dermatology” Microspheres about 1.5 micrometers in size can best penetrate hair follicles, potentially reaching important stem cells.
The skin is a complex barrier for drug penetration, but understanding its structure and interactions can improve drug delivery methods.
128 citations,
July 2009 in “International Journal of Pharmaceutics” PEVs improve minoxidil skin penetration, increasing 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.
54 citations,
October 2002 in “Journal of controlled release” Medium lipophilic substances penetrate skin best, and adding ethanol can increase delivery to hair follicles.