Thickening a Vitamin C Serum Formula
Question
I have the following formula for a Vitamin C serum:
Group A
- Distilled Water 43.7g
- Triethanolamine (TEA) (Alkaline, used to adjust pH to approximately 3.7) 2.5g
- Ferulic Acid (Antioxidant, helps stabilize Vitamin C LAA) 0.5g
- Panthenol (Vitamin B5, helps moisturize skin) 0.5g
Group B
- Ethoxydiglycol (Solvent and penetration enhancer) 20g
- Propylene Glycol (Solvent and lubricant) 10g
- Glycerin (Lubricant, moisturizer, provides a smooth feel on skin) 3g
- Laureth-23 (Emulsifier or water-oil binder, solid type, easy to use) 3g
- d-Alpha Tocopherol (Vitamin E, helps stabilize Vitamin C and provides antioxidant benefits for skin) 1g
Group C
- L-ascorbic acid (Our main active ingredient, Vitamin C) 15g
Group D
- Hyaluronic Acid Standard (Provides moisture) 0.3g
- Hyaluronic Acid Nano (Provides moisture) 0.5g
(Note: The reason Skinceuticals includes Hyaluronic Acid is likely to enhance skin hydration, as Vitamin C doesn't provide this benefit.)
I would like to know if there are any ingredients I can add to make the texture of this formula thicker, similar to a gel or cream, without causing the Vitamin C to degrade. Please provide recommendations. Thank you.
Answer
Thickening a Vitamin C Serum Formula
To increase the viscosity of your L-ascorbic acid serum formula to a gel or cream-like texture without compromising the stability of Vitamin C, you can incorporate specific thickeners that are compatible with acidic environments.
Based on your formula and the need for acid compatibility, here are some suitable thickeners:
- CreamMaker Acid™: This ingredient is specifically designed for low pH formulations and works well as an emulsifier and thickener in acidic systems like those containing L-ascorbic acid. It can help achieve a creamy texture.
- Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer: This thickener is effective over a wide pH range (3-12), making it suitable for your acidic formula. It can help create gel or serum textures.
- Sepimax Zen: Known for its high tolerance to salts and varying pH levels, Sepimax Zen can be used to thicken the water phase of your formula and create a gel texture.
When adding any thickener, start with a low percentage (e.g., 0.1-0.5%) and gradually increase it while observing the texture and stability of the formula. It is crucial to perform stability testing to ensure the L-ascorbic acid remains stable over time after adding the thickener.
Always follow the supplier's recommended usage rate and mixing instructions for the specific thickener you choose.
Related Products Mentioned
Vitamin E (Tocopheryl Acetate)
Pure-Ferulic Acid™
Vitamin C (L-ascorbic acid) (Ultra-Fine)
Vitamin C (L-ascorbic acid) (Fine)
Vitamin E (dl-alpha tocopherol)
Ethoxydiglycol (e.q. Transcutol)
Propylene Glycol (USP)
Triethanolamine 99%
Laureth-23
Glycerin (USP/Food Grade)
Sepimax Zen
