Adding Xanthan Gum and Homogenizer Speed in Vitamin C Serum Formulation

Question

I have the following serum formulation. Could you advise on when to add Xanthan gum and what speed to use with a homogenizer?

Formula:

Phase A:
- Distilled Water: 43.7g
- Triethanolamine (TEA): 2.5g (for pH adjustment to approx. 3.7)
- Ferulic Acid: 0.5g (Antioxidant, helps stabilize LAA Vitamin C)
- Panthenol (Pro Vitamin B5): 0.5g (Skin moisturizer)
Phase B:
- Ethoxydiglycol: 20g (Solvent, penetration enhancer)
- Propylene Glycol: 10g (Solvent, lubricant)
- glycerin: 3g (Lubricant, moisturizer, provides slip)
- Laureth-23: 3g (emulsifier)
- d-Alpha Tocopherol (Vitamin E): 1g (Helps stabilize Vitamin C, antioxidant)
Phase C:
- L-ascorbic acid (Vitamin C): 15g

Questions:

When should I add Xanthan gum to this formula?
What speed should I use with a homogenizer?

MySkinRecipes Expert · Accepted Answer

Based on the formula you provided, which includes a water phase (Phase A) and other ingredients, Xanthan gum, which is a water-soluble thickener, should typically be added to the water phase (Phase A).

To prevent clumping, it's best to first disperse the Xanthan gum in a small amount of liquid from Phase A (like distilled water) or in the glycerin from Phase B before adding this dispersion to the rest of Phase A while stirring continuously. Ensure it is fully hydrated and lump-free before proceeding.

Regarding the homogenizer speed, the optimal speed depends on the specific homogenizer model and the desired viscosity and stability of your final serum. Generally, you would start with a lower speed to incorporate the phases and then gradually increase it as needed to achieve a smooth, stable emulsion or dispersion. Avoid excessively high speeds initially, which can sometimes introduce air bubbles. You may need to experiment to find the best speed for your equipment and formulation.