To develop a popular sunscreen formula, the following technical points are generally considered: the selection and compatibility of sunscreen agents and oils; the combination of sunscreen synergists and film-forming agents; the selection of emulsification systems; the addition of skin texture adjustment ingredients, etc. So, what role do silicone materials play in sunscreen formulas?
Refreshing effect – volatile silicone oil
Sunscreen agents with strong sun protection capabilities are usually in a solid state. When designing refreshing sunscreen formulas, liquid oil sunscreen agents with moderate solubility need to be combined with highly volatile silicone oil to provide a refreshing skin feel, especially in W/ O formula system.
Sun protection and waterproofing – silicone film former
Use W/O system sunscreen, because most of the sunscreen is in the external oil phase, and the sunscreen ingredients can be spread continuously, while the oil-soluble sunscreen in the O/W system stays in the oil phase, and the sunscreen is easily dispersed and discontinuous after application, creating a “window” effect”, thereby reducing the effectiveness of sun protection. Therefore, it is necessary to use water-soluble sunscreen agents and add film-forming agents to enhance the waterproof and sunscreen effects of the formula.
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 and need to be used together when designing formulas.
Skin texture regulator – silica micropowder
The birth of powder raw materials provides sunscreen products with more skin feel styles. Commonly used powder raw materials include: microsilica powder, which can improve the smoothness of the skin; compound silica powder, which makes the skin feel softer and closer to the skin.
Improve compatibility and skin fit – phenyl silicone oil, alkyl silicone wax
The molecular polarity of organic sunscreen agents is generally high, so when choosing oils, you should choose oils with medium to high polarity. Phenyl silicone oil and alkyl silicone wax are polymers with a hydrocarbon branched chain structure connected to the silicone oil chain. It has good compatibility with highly polar oils. Adding phenyl silicone oil and alkyl silicone wax can increase the compatibility between oils in the oil phase system and improve the skin fit of the product.
