Beta‐Hydroxy Acids from a Formulation Point of View

Abstract

The difference from a formulation point of view between a di‐carboxylic acid and its two related hydroxy acids with one and two hydroxy groups was investigated by comparing the structure of their emulsions with a simple nonionic surfactant as stabilizer and the changes taking place during evaporation.

The results showed that the introduction of a hydroxy group into the structures has radical impact on the structure of the emulsion, especially the changes during evaporation.

An evaluation of the volume fraction of vesicles in the emulsion showed these to occupy a larger volume than is intuitively assumed.

Keywords:

• Alpha and beta hydroxy acid
• emulsion
• evaporation
• vesicles
• formulation