Mixing Glycolic Acid and Lactic Acid & Ingredient Solubility

Mixing Glycolic Acid and Lactic Acid

Yes, you can mix Glycolic Acid (100% Powder) and Lactic Acid (88%) in a formulation. Combining different AHAs like Glycolic Acid and Lactic Acid is a common practice to leverage their combined benefits, such as enhanced exfoliation and hydration.

Your proposed concentrations of 5% Glycolic Acid and 5% active Lactic Acid (which requires 5.68% of the 88% Lactic Acid solution) result in a total active AHA concentration of 10%. This concentration is generally within the typical limits for consumer cosmetic products, provided the final formulation's pH is correctly adjusted.

The most crucial step when formulating with AHAs is to ensure the final pH of your product is appropriate for both efficacy and safety. For a 10% total AHA product, the pH should ideally be between 3.5 and 4.0. You must use a pH meter to measure the pH and adjust it if necessary, for example, by adding a small amount of Lactic Acid if the pH is too high.

Dissolving Oil-Soluble Solids in Other Solvents

Whether a solid ingredient that dissolves in oil can also dissolve in other solvents like glycols depends entirely on the specific chemical properties of that ingredient.

Solubility is specific to the interaction between the solute (the ingredient) and the solvent (like oil or glycol). While some substances may be soluble in both oils and certain glycols, this is not universally true. Glycols are chemically different from oils and may not be able to dissolve all the same substances.

To determine if a specific oil-soluble solid ingredient will dissolve in a glycol or other non-oil solvent, you would need to consult the ingredient's technical data or perform a solubility test.