defender of system stability – silicone emulsifier
silicone emulsifiers are often used in w/o emulsification systems. generally, emulsifiers with strong emulsifying ability have a relatively large molecular weight, large hydrophilic and lipophilic groups, and a thicker skin feel when used. emulsifiers with relatively small molecular weights will have weaker emulsifying power and stability, but will have a refreshing skin feel when used, so they need to be used in conjunction with formula design.