Cutaneous Irritation to Sodium Lauryl Sulfate and Sodium Lauroyl Glutamate

Lee, Kyung Ywal; Shin, Kyung Yul; Park, Chun Wook; Lee, Cheol Heon

Abstract

BACKGROUND: Sodium lauryl sulfate(SLS) is the most widely utilized model for studying acute and cumulative irritation. Sodium lauroyl glutamate(SLG) has exhibited a low irritation potential and an anti-irritating effect on other anionic surfactants.
OBJECTIVE
Our study was done to compare the skin irritancy of SLS and SLG using non-in- vasive techniques.
METHODS
Patches with 1% SLS and SLG solution were applied to the volar forearm of 20 healthy volunteers for 24 h. Finn chambers with 8mm(20pl) and 12mm(60pl) inner diameters were used. Visual scores, transepidermal water loss(TEWL) and an erythema(E)-index were measured at 30 min after removal of the patches, and every 24hours(h) up to 4 days.
RESULTS
The results are summarized as follows. 1. Visual scores were 0.20+0.30(8mm) and 0.73+0.34(12mm) at 24 h after removal of 1% SLS and were 0.15+0.29(8mm) and 0.30+0.41(12mm) at 24 h after removal of 1% SLG. They were increased at 30 min and 24 h after removal and decreased towards normal at 4 days after removal. By chamber size, the skin response with large Firin chamber(12mm) increased more significantly than with the small Finn chamber(8mm). In the small Finn chamber, there were no significant differences in the skin response between 1% SLS and 1% SLG. In the large Finn chamber, the skin response with 1% SLS increased more significantly than with 1% SLG. 2. TEWL values were 11.14+4.77(8mm) and 20.48+10.61(12mm) at 24 h after removal of 1 % SLS and were 10.38+3.99 and 14.87+7.46 at 24 h after removal of 1% SLG. They were increased at 30 min after removal and decreased towards normal 4 days after removal. By chamber size, their results were the same as the visual scores. Also, on comparison between 1% SLS and 1% SLG, their results were the same as the visual scores. 3. E-index was 10.05+2.70(8mm) and 11.15+2.56(12mm) at 24 h after removal of 1% SLS and was 10.15+2.16 and 10.60+2.26 at 24 h after removal of 1% SLG. They were increased at 30 min after removal and decreased towards normal 4 days after removal. By chamber size, their results were the same as the visual scores. In the small and large Finn chamber, there were no significant differences in the skin response between 1% SLS and 1% SLG.
CONCLUSION
SLS is more irritating than SLG. The large Finn chamber may be more suitable to yield positive irritant reactions than the small Finn chamber. Also, TEWL measurements may be a more accurate and sensitive method than the E-index.