Under-Eye Serum Formulation with Vitamin C Derivatives

Yes, you can definitely use Vitamin C derivatives like Sodium Ascorbyl Phosphate (SAP) or Magnesium Ascorbyl Phosphate (MAP) in an under-eye serum formulation. These forms of Vitamin C are known for their stability and are water-soluble, making them suitable for serum formulations.

Recommended Usage and Formulation Tips:

• Usage Rate: Both SAP and MAP can be used at concentrations ranging from 0.5% to 10%. A commonly recommended concentration for good efficacy is 3%. Using concentrations higher than 8% might lead to solubility issues in the formula.
• pH Requirement: SAP and MAP are alkaline forms of Vitamin C. Your serum formulation should have a pH in the range of 7-9 for optimal stability and effectiveness. The ideal pH range is typically 7-8.
• Stability: To further enhance the stability of SAP or MAP in your formulation, it is recommended to include Disodium EDTA at a concentration of around 0.05%. This helps chelate metal ions that could degrade the Vitamin C derivative.
• Mixing Method: Mix SAP or MAP into the water phase of your formulation. Avoid heating the mixture above 60°C.
• Storage: For long-term stability, store the finished product in the refrigerator and protect it from sunlight and humidity.

Basic Serum Formulation Structure (Example):

A simple serum base can include:

1. Water Phase: Purified Water (ส่วนของน้ำ)
2. Humectants: Glycerin, Butylene Glycol, Propanediol (สารให้ความชุ่มชื้น)
3. Gelling Agent/Thickener: Carbomer, Xanthan Gum, or other suitable thickeners to create serum texture (สารสร้างเนื้อเจล/ข้น)
4. Active Ingredient: Sodium Ascorbyl Phosphate (SAP) or Magnesium Ascorbyl Phosphate (MAP) at your desired concentration (e.g., 3%)
5. Stabilizer: Disodium EDTA (สารช่วยเพิ่มความคงตัว)
6. pH Adjuster: Sodium Hydroxide or Triethanolamine solution to adjust pH to 7-9 (สารปรับค่า pH)
7. Preservative: Suitable broad-spectrum preservative (สารกันเสีย)

Remember to mix ingredients properly, ensuring the Vitamin C derivative is fully dissolved, and adjust the pH to the correct range after adding all ingredients (except the preservative, which is usually added last).