Green Clay Mask Formulation using Carbomer

Question

I want to make a Green Clay Mask formulation using `Carbomer` as the thickener. The formula should include ingredients like `Salicylic Acid`, `Centella Asiatica Extract`, and clays (`Green Clay`, `Kaolin`). How can I formulate this mask, especially considering the need to neutralize `Carbomer` and the pH sensitivity of `Salicylic Acid`? Please provide a detailed formula and method.

MySkinRecipes Expert · Accepted Answer

Green Clay Mask Formulation (with Carbomer)

Ingredient	Percentage (%)	Function	Notes
Water	43.2	Solvent	Purified water
Carbomer 940	0.8	Thickener, Gelling Agent	Requires neutralization with alkali
Glycerin	5.0	Humectant, Solvent	Helps hydrate skin and dissolve ingredients
Natural Betaine	3.0	Moisturizer, Anti-irritant, Solubility Aid	Helps dissolve Allantoin and Salicylic Acid, reduces irritation
Allantoin	0.5	Soothing, Skin Protectant	Helps reduce irritation
DMDM Hydantoin	0.5	Preservative	Broad-spectrum preservative
Cyclopentasiloxane	5.0	Emollient, Texture Enhancer	Provides smooth feel, evaporates quickly
Trilaureth-4 Phosphate	2.0	Emulsifier, Solubilizer	Helps blend oil/silicone phase into water phase, improves texture
Propylene Glycol	5.0	Solvent	Required to dissolve Salicylic Acid
Salicylic Acid	1.0	Exfoliant, Anti-acne	Needs to be dissolved in solvent; pH sensitive for efficacy
Triethanolamine	0.5 (approx.)	Neutralizer	Alkali needed to activate Carbomer; adjust for desired thickness/pH
Centella Asiatica Extract	1.0	Skin Conditioning, Soothing	Add in final step, pH sensitive
Tea Tree Oil (Water Soluble)	1.0	Active, Fragrance	Provides scent and benefits; water soluble type is easier to use
Green Clay	20.0	Absorbent, Colorant, Texture	Provides mask properties and green color
Kaolin	10.0	Absorbent, Texture	Helps absorb oil and refine texture
Total	100.0

Note: The percentage for Triethanolamine is an estimate. You will need to add it slowly and adjust based on the desired thickness and pH.*

Method for Making the Mask

Prepare Phase A (Water Phase):
- In a clean beaker or container, add the Water.
- Slowly sprinkle the Carbomer 940 powder onto the surface of the water while stirring gently to avoid clumping.
- Let the mixture sit for 15-30 minutes to allow the Carbomer to hydrate fully.
- Once hydrated, mix well to ensure the Carbomer is evenly dispersed.
- Add Glycerin, Natural Betaine, Allantoin, and DMDM Hydantoin to the water phase. Mix until all powders are dissolved and liquids are uniformly dispersed.
Prepare Phase B (Oil/Silicone Phase):
- In a separate container, combine Cyclopentasiloxane and Trilaureth-4 Phosphate. Mix well.
Prepare Phase C (Salicylic Acid Solution):
- In a small container, add Propylene Glycol.
- Add Salicylic Acid powder to the Propylene Glycol. Stir or gently warm (do not overheat) until the Salicylic Acid is completely dissolved. Ensure there are no solid particles remaining.
Combine Phases:
- Add Phase B (Oil/Silicone Phase) to Phase A (Water Phase) while mixing continuously.
- Then add Phase C (Salicylic Acid Solution) to the mixture while mixing.
Neutralization and Thickening:
- While mixing, slowly add Triethanolamine drop by drop.
- Continue adding Triethanolamine until the mixture begins to thicken and forms a smooth, creamy gel texture.
- Crucially, monitor the pH as you add the Triethanolamine. Carbomer requires a pH of 6-7 to fully gel. However, Salicylic Acid is most effective at a lower pH (around 3-4). Aim for a final pH around 5.5-6. This pH range is a compromise that allows the Carbomer to gel sufficiently while keeping the pH low enough for some Salicylic Acid activity, but it may not be ideal for maximum efficacy of both ingredients or long-term stability.
Add Actives and Fragrance:
- Once the desired consistency and pH are achieved, add Centella Asiatica Extract and Tea Tree Oil (Water Soluble).
- Mix thoroughly until these ingredients are evenly distributed. Avoid vigorous mixing that could incorporate too much air.
Add Clays:
- Gradually add Green Clay and Kaolin to the mixture while mixing.
- Continue mixing until the clays are fully dispersed and the mask has a smooth, uniform green color and texture.
Final Check:
- Check the final consistency and pH. Make minor adjustments if necessary, but significant changes after adding clays are difficult.

This method should result in a thick, soft cream mask with the ingredients you specified. Remember that careful pH control is essential when using Carbomer, especially in formulations containing acidic ingredients like Salicylic Acid.