Fujii M, Inoue M, Fukami T
Department of Molecular Pharmaceutics, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan.
Milott Cosmetic Corporation, 2976-12 Sugetacho, Yokohama, Kanagawa, 221-0864, Japan.
Int J Cosmet Sci. 2017 Oct;39(5):556-563. doi: 10.1111/ics.12414. Epub 2017 Aug 15.
Quaternary ammonium cationic surfactants (ACSs) and N-[3-alkyl(12,14)oxy-2-hydroxypropyl]-l-arginine hydrochloride (N-AOHPA) were used to emulsify silicone. The potential of the resulting emulsions in hair conditioning products was investigated.
The emulsions were prepared using a homogenizer and/or high-pressure homogenizer. ACSs and N-AOHPA were used as silicone emulsifiers. The stability of the emulsions was evaluated by measuring particle sizes, creaming fractions, polydispersity indexes and zeta potentials. Moreover, the N-AOHPA-stabilized emulsion was compared with the ACS-stabilized emulsion to evaluate the adsorption amount of silicone on healthy and bleached hair surfaces and the inhibitory effects on amino acid dissolution from bleached hair. The adsorption site of the N-AOHPA-stabilized emulsion was observed using a scanning electron microscope.
For all surfactants, the silicone emulsions prepared using the high-pressure homogenizer were more stable than those prepared using the homogenizer. When N-AOHPA was used as the surfactant, the silicone emulsion was especially stable. Furthermore, the d50 value of the N-AOHPA-stabilized emulsion was smaller than that of the ACS-stabilized emulsion. The adsorption behaviour of the silicone droplets in the different emulsions varied depending on the nature of the surfactant and the preparation method. The amount of ACS-stabilized silicone adsorbed on healthy hair was higher than that adsorbed on bleached hair, especially when the emulsion was prepared using the homogenizer. In contrast, the amount of N-AOHPA-stabilized silicone adsorbed on bleached hair was high, and no differences were observed between the N-AOHPA-stabilized emulsions prepared using the homogenizer and high-pressure homogenizer. The emulsified droplets, especially the N-AOHPA-stabilized droplets prepared using the high-pressure homogenizer, prevented amino acid dissolution from bleached hair. It was concluded that the silicone droplet adsorption site affected the dissolution process because the small N-AOHPA-stabilized droplets adsorbed at cuticle edges.
This study shows that N-AOHPA has good potential for use as an emulsifier in products used for improving the condition of damaged hair.
使用季铵阳离子表面活性剂（ACSs）和N-[3-烷基（12,14）氧基-2-羟丙基]-L-精氨酸盐酸盐（N-AOHPA）乳化硅氧烷。研究所得乳液在头发调理产品中的应用潜力。
使用均质器和/或高压均质器制备乳液。ACSs和N-AOHPA用作硅氧烷乳化剂。通过测量粒径、乳析率、多分散指数和zeta电位来评估乳液的稳定性。此外，将N-AOHPA稳定的乳液与ACS稳定的乳液进行比较，以评估硅氧烷在健康和漂白头发表面的吸附量以及对漂白头发中氨基酸溶解的抑制作用。使用扫描电子显微镜观察N-AOHPA稳定乳液的吸附位点。
对于所有表面活性剂，使用高压均质器制备的硅氧烷乳液比使用均质器制备的乳液更稳定。当使用N-AOHPA作为表面活性剂时，硅氧烷乳液特别稳定。此外，N-AOHPA稳定乳液的d50值小于ACS稳定乳液的d50值。不同乳液中硅氧烷液滴的吸附行为因表面活性剂的性质和制备方法而异。ACS稳定的硅氧烷吸附在健康头发上的量高于吸附在漂白头发上的量，尤其是当使用均质器制备乳液时。相比之下，N-AOHPA稳定的硅氧烷吸附在漂白头发上的量很高，并且使用均质器和高压均质器制备的N-AOHPA稳定乳液之间没有观察到差异。乳化液滴，尤其是使用高压均质器制备的N-AOHPA稳定液滴，可防止漂白头发中的氨基酸溶解。得出的结论是，硅氧烷液滴吸附位点影响溶解过程，因为小的N-AOHPA稳定液滴吸附在角质层边缘。
本研究表明，N-AOHPA在用于改善受损头发状况的产品中具有良好的作为乳化剂的应用潜力。
