Hello
I want to formulate a serum to be applied on skin where pigmentations are seen. I want to apply this before applying night serum with moisturizing properties.
It might be easier if you add these
whitening ingredients into your night serum so you don't have to separate the formulation.
You are using very high concentration of 1,3-
Propanediol . We aren't sure what's intention of using such high conc as 3-5% would be sufficient for most formulations. If you are ex
Pectin g it to help penetrating the skin, you already have
Ethoxydiglycol which should be enough. We've seen some research showing that using very high polyols intending to help penetrate the skin gives negative result as it creates "reservoir" effect on the skin and the active ingredients stays in the reservoir instead of penetrate with good flux. 2. 2.5% is enough.