A comparison of the effect of certain inorganic salts on suppression acute skin irritation by human biometric assay: A randomized, double-blind clinical trial

Strontium, zinc, and potassium salts have been demonstrated to inhibit irritation and infl ammation 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 eff ects of four inorganic salts and assign the ingredient which can suppress skin irritation due to chemical or environmental exposure, more eff ectively. We compared the anti-infl ammatory eff ects of SC, strontium nitrate (SN), KN, and zinc chloride (ZC).
This double-blind trial was conducted on 32 healthy volunteers with sensitive skin. Irritation was induced by 24 h and 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.
SC had a benefi cial eff ect that was signifi cant overall. All other treatments exert a protective eff ect in skin barrier function but not significantly. With the exception of ZC, all test substances improved skin hydration but the eff ect of SC was signifi cant. In respect of colorimetric assessment, all treatments, excluding ZC, reduced erythema significantly compared with an untreated control 7 days after treatment start. Th ere was no support for a dose-response eff ect.
Analysis of the biometric measurements revealed that the strontium salts are best, not treating is worst, and there is little diff erence between the other treatments. Hence, the skin care products containing SC and SN may reduce the signs and symptoms of irritant contact dermatitis.