title: The effect of volatility on percutaneous absorption.
abstract: BACKGROUND
  Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy.
  
  
  METHODS
  A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption.
  
  
  RESULTS
  A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs.
  
  
  CONCLUSIONS
  Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.
authors.affiliation: a Department of Osteopathic and Neuromuscular Medicine , Western University of Health Sciences COMP , Pomona , CA , USA and.
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Rouse
authors.affiliation: b Department of Dermatology , University of California , San Francisco , CA , USA.
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D003358:Cosmetics / Q000008:administration & dosage; D006801:Humans; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D014835:Volatilization
chemical_list: D003358:Cosmetics
keywords: Dermatology; efficacy; evaporation; exposure; pharmacology; safety; toxicity