- Skin and cosmetics

Skin cells are arranged like a neat pile of blocks structures. Water and oil ingredients can be like brick of cement. It is common knowledge that water and oil do not mixed at all. How immiscible substances could fill the intercellular space? According to the recent study from Biotech, immiscible water and oil within intercellular space have been shown layer upon layer structure like water-oil-water-oil layer. In particular, oil layers structure has similar components and has actually similar structure with cell membrane.

Liposomes and skin delivery system

There are two ways to permeate active ingredient through skin. One way is directly permeate through cells and the other is by intercellular. The pore of the skin is expected to permeate active ingredient well, but actually pore of skin can permeate only about 1% of effectiveness components. In fact, pore of skin release sebum and sweat from the body. Instead of effectiveness components are permeated well via intercellular. Since skin intercellular is filled with mortar as can be seen in the picture, only liposome can be passed without any irritation because it has similar compound and structure with mortar layer.

When you want to deliver beneficial ingredients to dermis layers or deep into skin, technical development might be difficult without understanding of skin structure. The current cosmetic manufacturing methods have various formulation technologies however mostly depend on surfactant method. The lotion is made by suitable ratio of water, oil and surfactant; surfactant help felicitously mix water and oil. Furthermore, increasing viscosity of the lotions is just creamy. Unfortunately, some cosmetic companies use low quality of synthetic oil or synthetic surfactants for reducing their manufacturing cost.

If oil is felicitously mixed water, oil forms micelle. Typically, micelles have crystal-like structure and differ in size from 1μm to several μm. Micelles cannot easily pass through the skins intercellular even though the size of skin intercellular is from 30μm to 100μm. Thus, even though good ingredient for our skin has been developed as cosmetics product, it is difficult to expect significant effect with the common cosmetic formulation. To rectify this problem, several cosmetic companies have been studied about permeation to maximize effectiveness of components in skin intercellular for several years. In summary, hydrophilic than hydrophobic substances and small particle than big particle substances can be permeate into the skin better. Moreover liposome is optimized technology that active ingredients permeates into intercellular without any irritations and safety issues.

However, liposome needs to satisfy several conditions such as expensive manufacture cost; required to 3 to 5 times more than normal cost in terms of proficient experts and specific equipment. It is almost impossible to satisfy all conditions and mass production at the same time. For this reason, liposome is used widely in raw material stage and a few companies apply liposome skills to finished product at present.

Finally, skin has cognitive functions of external environment and reactions. Nerves are distributed in the skin to detect external environment changes. The primary functions of the skin are sense of pain, touch, pressures and so on. Sense of nerve endings receptor is evenly distributed throughout the skin therefore it can deliver information to brain to plan next reaction under the changed environment by detecting pain, hot, cold, soft and rough feelings.