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.
C12-15 Alkyl Benzoate is mostly used as formulation component. It gives the product a soft and silky but non-greasy feeling. As for the skin benefits, it's an emollient – it makes the skin softer and more hydrated. It also helps to kill bacteria and increase the product’s shelf life.
Propylene Glycol is a useful componet with many positive effects. It’s a very good moisturizer. It helps to deliver ingredients into deeper layers of the skin. It creates a protective layer on the skin preventing water loss. The component is researched very well and doesn’t have notable side effects. It’s used even for making food.
Isododecane is an emollient and a good base for colorants. Very often used in powders and shades because it spreads on the skin nicely. It also helps to soften the skin and helps to lower water loss making all the moisturizing components work better.