Water is a great solvent. It’s neutral and doesn’t provide any strong positive or negative effects. It just helps components to mix better and to transport active components.
Gluconolactone belongs to poly hydroxy acids (PHA). It’s very similar to AHAs chemically, that’s why it is usually presented as a «Next Generation AHA». It has all the benefits of AHA but it doesn’t irritate the skin. It’s a strong natural antioxidant which is as strong as Tocopherol or Ascorbic Acid.
Propanediol is a good solvent, emollient and humectant. It helps to moisturize the skin and prevent moisture loss. In haircare products, it conditions hair and improves absorption of the product.
Silica is used for improving texture of the product. It helps the product to spread out evenly. Very often it’s used in different exfoliants as an abrasive. It's safe and non-toxic.