Microencapsulation and Its Application in Sunscreens

Sunscreen is one of the best-known methods for protecting the skin from the effects of ultraviolet radiation. In recent years, rising awareness of the need for UV protection has fueled growing demand for sunscreens that are fit for daily use, not just outdoor recreation. For daily use, consumers want a sunscreen that offers a clean, pleasant skin feel as well as high UV protection. Generally, sunscreens made in the form of W/O (water-in-oil) emulsions have higher and longer-lasting UV protection, but they also leave a greasy feeling on the skin. On the other hand, O/W (oil-in-water) emulsions offer a more comfortable, moisturizing texture but are difficult to formulate with a high concentration of UV scattering agents, and their protection tends to wear off faster.

Kao’s answer to this dilemma was to develop a new emulsion technology, C-P/O/W (encapsulated powder-in-oil-in-water). In this type of emulsion, hydrophobic UV scattering agents in powder form (P) is dispersed in an oil phase (O), which is in turn surrounded by a water phase (W). The interface between the oil phase and the surrounding water phase forms a shell of tight multilayer structure around the oil phase, in other words, forms a capsule (C). By applying this C-P/O/W technology, we have been able to provide consumers with a sunscreen that is pleasant and safe to use on a daily basis while providing a high level of UV protection.

C-P/O/W (encapsulated-P/O/W) emulsion