34 citations
,
July 2010 in “Expert Opinion on Drug Delivery” The document concludes that there is no agreed-upon best method for measuring drug delivery within hair follicles and more research is needed to validate current techniques.
11 citations
,
February 2012 in “International journal of pharmaceutics” Ultrasound increases skin permeability but blocks hair follicles.
42 citations
,
January 2007 in “Pediatric dermatology” Low-potency steroids can cause serious side effects in people with skin conditions like Netherton syndrome.
52 citations
,
February 1985 in “Archives of Dermatology” Minoxidil absorbs poorly through skin, with low risk of side effects at 1-2% concentration.
94 citations
,
May 2011 in “BJCP. British journal of clinical pharmacology/British journal of clinical pharmacology” Hair follicles greatly increase caffeine absorption through the skin shortly after it's applied.