Water-Free Vitamin C Serum Formulation Issues and Alternatives

Question

How can I formulate a water-free serum containing 20% L-ascorbic acid powder using ingredients like Ethoxydiglycol, Propylene Glycol, Glycerin, or Silicone? Is L-ascorbic acid soluble in these bases, and what are the potential issues like precipitation? What alternative methods are recommended for a stable water-free L-ascorbic acid formulation?

MySkinRecipes Expert · Accepted Answer

Water-Free Vitamin C Formulation

Based on the information, your proposed formula for a water-free Vitamin C serum using L-ascorbic acid powder with Ethoxydiglycol, Propylene Glycol, and Glycerin is not feasible.

Here's why:

Solubility: L-ascorbic acid does not dissolve well in Glycol or Glycerin. At a concentration of 20%, it will not dissolve completely and will likely leave a precipitate in the formula.
Silicone: Silicone does not dissolve L-ascorbic acid.

Recommended Alternative Approach:

A recommended method for a water-free Vitamin C formulation is to disperse L-ascorbic acid Ultra-Fine powder in a water-free gel base, such as Silicone Gel (Vinyl Dimethicone Crosspolymer). The powder will remain suspended in the gel and will dissolve on the skin upon application, using the skin's moisture.

Preservative:

In a completely water-free formulation like the suggested Silicone Gel base, a traditional preservative against microbial growth is generally not necessary.