Abstract:
The mix surfactant systems which gave the larger micelles size were developed to reduce Sodium Lauryl Sulfate (SLS) irritation. Sodium Cocoamphoacetate, Cocamidopropyl Betaine, Decyl Glucoside and Cocamide DEA were chosen to combine with SLS. The concentration of SLS were prepared at 34.7 mM while co-surfactants were varied from 8.7, 23.2 and 34.7 mM, respectively. The 13 in 15 systems showed significant higher foam volume than SLS alone (more than 5% w/w). Systems which gave larger micelles size compared to SLS (5.07 ± 0.73 nm) were SLS/AMP2C, SLS/AMP2/NON1 and SLS/AMP2/NON2 (10.67 ± 0.25, 28.04 ± 1.96 and 19.16 ± 1.29 nm, respectively). The irritation test by measuring the increasing pH after protein incubation showed that these mix surfactant systems increased lower than that of SLS (1.31 ± 0.02). The collagen swelling also lower in SLS/AMP2C (9.08 ± 0.04) and SLS/AMP2/NON1 (9.03 ± 0.24) compared to SLS (11.45 ± 0.16). Irritation test in 4 male, 16 female by taking 10 ml of samples to test on volunteers forearm repeated 3 times for 3 minutes each and evaluation the erythema index showed that SLS/AMP2C (41.31 ± 19.87) and SLS/AMP2/NON1 (47.53 ± 25.04) gave a smaller difference than SLS (65.96 ± 22.58). These mix surfactant systems with larger micelles size caused lower irritation than SLS.