The 500 Dalton Rule Molecules Too Large To Penetrate Skin
By Bill Soukup, Anti-Aging Extracts LLC
The human skin has numerous unique properties. The most important one, though, is functioning as a physicochemical barrier. When manufacturing cosmetics, it’s essential to take a look at the skin’s structure to understand better how it resists the absorption of some molecules while allowing others to pass. The 500 Dalton Rule states that the molecular weight of a compound should be under 500 Daltons for it to pass through the skin. This rule could have massive implications for how companies manufacture their cosmetics.
Which Molecules Can Pass-Through?
A molecule’s permeability depends on a variety of factors such as:
- What the pH and concentration values of all its components are
- How weak the concentration of acid is
- How stable the molecule is
- The solubility of the molecule
- The strength with which It can bind to other molecules
- Molecular weight less than 500 Daltons.
What Is the 500 Dalton Rule?
The 500-Dalton rule states that for a substance to be able to cross the skin barrier, it must have a molecular weight of fewer than 500 Daltons. Though there are certain exceptions to this rule, it is generally considered as a standard rule of thumb for cosmetic manufacturers.