Vitamin C Serum Formulation: Mixing and Stability

Hello,

Regarding the latest Vitamin C serum formula proposed by you, tanareenook, which includes:

• Silky Serum Base Plus 15%
• L-ascorbic acid 15%
• Cyclomethicone 7%
• Vit E 0.5 %
• Distilled Water 55.4 %
• Glutathione 1.5%
• Ferulic Acid 0.5%
• Ethoxydiglycol 5%
• EDTA 0.1%

Our team has reviewed it and found that this formula can be mixed together, as it contains water (Distilled Water), which is necessary for dissolving L-ascorbic acid.

Further Recommendations on Formulation and Mixing Procedure:

1. Ingredient Percentages:

   • The percentages you proposed add up to 100%, which is a good starting point.
   • The concentrations of the main active ingredients, such as L-ascorbic acid 15%, Glutathione 1.5%, and Ferulic Acid 0.5%, are considered high and potent for skin benefits.
   • The amounts of Distilled Water (55.4%), along with Silky Serum Base Plus (15%) and Cyclomethicone (7%), will be the main components determining the texture and feel of the serum. Ethoxydiglycol (5%) acts as a solvent and helps deliver active ingredients. EDTA (0.1%) helps improve formula stability.
   • You can adjust the percentages of the base and solvent components (e.g., Distilled Water, Silky Serum Base Plus, Cyclomethicone, Ethoxydiglycol) to achieve your desired serum texture (e.g., lighter or richer feel), while keeping the percentages of the active ingredients (L-AA, Vit E, Glutathione, Ferulic Acid) and EDTA at your desired levels.

2. Mixing Procedure:

   • Phase 1 (Water Phase): In a clean beaker, combine Distilled Water, L-ascorbic acid, Glutathione, Ferulic Acid, and EDTA. Stir or use a stirrer until all solid ingredients are dissolved. Gentle warming (e.g., placing the beaker in a warm water bath) can help dissolve Ferulic Acid, but be careful not to overheat (recommended below 40°C) to preserve the quality of L-ascorbic acid. Once dissolved, let it cool down.
   • Phase 2 (Oil/Silicone Phase): In a separate beaker, combine Cyclomethicone, Vit E, and Ethoxydiglycol. Mix well.
   • Combining Phases: Slowly pour the mixture from Phase 2 into the mixture from Phase 1 while stirring continuously at a moderate speed until all components are well combined and the mixture appears homogeneous.
   • Add Base: Add Silky Serum Base Plus to the mixture. Continue stirring or mixing until the Silky Serum Base Plus is fully incorporated and the serum texture is uniform.
   • Add Preservative: It is crucial to add a preservative to the formula to prevent microbial growth, which can degrade the product and make it unsafe for use. We recommend choosing a preservative suitable for water-containing formulas and using it at the supplier's recommended usage rate (generally around 0.5-1% depending on the type of preservative). Phenoxyethanol (ID 155) is one commonly used option. Add the preservative to the serum and mix thoroughly.
   • Check pH: For optimal efficacy of L-ascorbic acid and to reduce degradation, it is important to check and adjust the pH of the serum to the appropriate range (generally L-AA is most effective at a pH of approximately 2.5-3.5). However, a very low pH can cause skin irritation. pH adjustment should be done carefully using an appropriate pH adjuster.

3. Stability Testing:

   • As you mentioned, tanareenook, stability testing of the formula is very important, especially if you plan to make it for long-term personal use or for commercial purposes. You should observe changes in the product's texture, color, odor, and separation when stored under different conditions (e.g., room temperature, in the refrigerator, or under accelerated conditions like high temperature).

We hope this advice is helpful in developing your Vitamin C serum formula. If you have any further questions, please feel free to ask.

Thank you,
Staff - MySkinRecipes