Aged skin is generally characterized by loss of collagen, degeneration in the elastic fiber network, and loss of hydration. In addition to these common features, a study has revealed that aged skin also has higher stratum corneum pH, i.e. aged skin surface is less acidic than younger skin surface. This will affect some pH-sensitive enzymes, which are related to the stratum corneum integrity and skin barrier recovery capability.
This study has also discovered that topical application of hydroxyacids can normalize the impaired skin acidity and thus restore skin barrier recovery rates (they used 10% lactobionic acid at pH 2). So there will possibly be one more reason for us to use hydroxyacids. In addition to the traditional AHAs, continued research has led to more choices of hydroxyacids. The following are some of the hydroxyacids in skin care products.
- Alpha hydroxyacids (AHAs): glycolic acid, and lactic acid.
- Lipophilic AHAs: benzilic acid (diphenyl glycolic acid), and mandelic acid (phenyl glycolic acid). Combined with salicylic acid, they are used to treat oily or acne-prone skin.
- Beta hydroxyacid (BHA): salicylic acid.
- Polyhydroxy acids (PHAs): gluconolactone, and glucoheptonolactone.
- Polyhydroxy bionic acids (bionic acids): lactobionic acid, and maltobionic acid.
[…] Irritating Exfoliation By Chelsea Yan | Email this article to a friend In previous posts Aged Skin Is Less Acidic – Hydroxyacids Can Help and Exfoliation – PHA, I talked about some benefits of PHAs. You might be wondering which […]