title: A comparison of the effect of certain inorganic salts on suppression acute skin irritation by human biometric assay: A randomized, double-blind clinical trial.
abstract: BACKGROUND
  Strontium, zinc, and potassium salts have been demonstrated to inhibit irritation and inflammation when applied topically. Particularly, strontium chloride (SC) and potassium nitrate (KN) are reported to reduce skin and tooth sensitivity. The aim of the present study was to compare the anti-irritant effects of four inorganic salts and assign the ingredient which can suppress skin irritation due to chemical or environmental exposure, more effectively. We compared the anti-inflammatory effects of SC, strontium nitrate (SN), KN, and zinc chloride (ZC).
  
  
  METHODS
  This double-blind trial was conducted on 32 healthy volunteers with sensitive skin. Irritation was induced by 24 h exposure with 1.0% sodium lauryl sulfate on arms. Treatments were applied by an ointment of SN, SC hexahydrate, KN, and ZC and their 1%, 3%, and 5% (w/v) concentrations were prepared. The dosage was twice daily for 6 days to the irritated areas. Skin reactions were evaluated instrumentally.
  
  
  RESULTS
  SC had a beneficial effect that was significant overall. All other treatments exert a protective effect in skin barrier function but not significantly. With the exception of ZC, all test substances improved skin hydration but the effect of SC was significant. In respect of colorimetric assessment, all treatments, excluding ZC, reduced erythema significantly compared with an untreated control 7 days after treatment start. There was no support for a dose-response effect.
  
  
  CONCLUSIONS
  Analysis of the biometric measurements revealed that the strontium salts are best, not treating is worst, and there is little difference between the other treatments. Hence, the skin care products containing SC and SN may reduce the signs and symptoms of irritant contact dermatitis.
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sayedali
authors.initials: S
authors.lastname: Fatemi
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Jafarian-Dehkordi
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Valiollah
authors.initials: V
authors.lastname: Hajhashemi
authors.affiliation: Department of Dermatology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Asilian-Mahabadi
authors.affiliation: Department of Cell and Molecular Biology, Royan Institute for Animal Biotechnology, Isfahan, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Nasr-Esfahani
keywords: Anti-irritation; contact dermatitis; potassium nitrate; sensitive skin; strontium chloride