Saturday, January 7, 2012

Lactic Acid 40 % Gel

Lactic Acid is an alpha hydroxy acid often used as a moisturizing ingredient as well as a gentle exfoliator. Most often lactic acid is purchased in a saturated liquid form, however that is not necessary if you have the 99% pure form available.

Ingredients Percent
Lactic Acid 40 %
Distilled water 40%
Sclerotium gum 2% stock sol'n20%


1. Prepare your tools and ingredients. 

2. Weigh your ingredients.
3. Combine your lactic acid with your water.

4.a.  Blend/ vigorously stir the lactic acid and water, it will be creamy white. 


4.b. There may be tiny grains, that is undesirable, to get it all into solution, place in the hot water bath and blend.

5. When the lactic acid has gone into solution, add the sclerotium gum and continue blending till homogeneous.

6. Remove and allow to cool while stirring.

7. Check the pH.
8. Your 40% lactic acid gel is quite thick and easy to work with. It can be used as a peel with greater control. No fear of watery acids running  and collecting/ pooling on the skin.

Please note pH and pKa.The gel is well below the pKa of 3.86 of Lactic acid. It is close to 100 % free acid.


To buffer the solution, use 0.5 M NaOH. Test it. When you buffer/ neutralize the solution you will reduce the free acid and the efficacy. 

TEST PATCH before using.