Sorbitan oleate is a monoester of oleic acid and hexitol anhydrides derived from sorbitol. Oleic acid is a monounsaturated omega-9 fatty acid that can be obtained from natural sources such as olive oil, peanut oil, and sunflower oil. Sorbitol is a sugar alcohol that is primarily made from corn syrup.
Sorbitan oleate has a structure with one hydrophilic (water-loving) end and one lipophilic (oil-loving) end, which allows it to function as both a surfactant and emulsifier in cosmetics and personal care products. Surfactants attract and suspend oil, dirt, and other impurities on the skin and wash them away. Due to these properties, sorbitan oleate can be found in many different cleansers and body washes.
Sorbitan oleate can be used as an emulsifier in formulations that contain both water and oil components. Mixing water and oil together creates a dispersion of oil droplets in water (and vice versa). These two phases can separate if the product is left to settle. To address this problem, an emulsifier can be added to help the droplets remain dispersed. With an HLB value of 4.3, sorbitan oleate is soluble in oil and gives rise to water-in-oil emulsions.