Serum Mixing Instructions and pH

Here are the recommended mixing steps and optimal pH for your serum formula containing Water, L-Ascorbic Acid, Lactic Acid, Zinc Sulfate, Phenoxyethanol, Bioflavonoids, and Sodium Hyaluronate.

Mixing Steps

1. Prepare the Water Phase: Start with the water component of your formula.
2. Add Water-Soluble Ingredients: Add ingredients like Sodium Hyaluronate, Zinc Sulfate, Bioflavonoids, and Phenoxyethanol to the water phase. Mix thoroughly until they are fully dissolved or dispersed.
3. Incorporate Lactic Acid: Add the Lactic Acid to the water phase and mix.
4. Adjust pH: This is a critical step. Before adding L-Ascorbic Acid, adjust the pH of your mixture. Use a suitable pH adjuster (like a dilute solution of Sodium Hydroxide or Citric Acid, depending on whether you need to raise or lower the pH) to bring the pH into the desired range.
5. Check Temperature: Ensure the temperature of the mixture is below 30°C before proceeding.
6. Add L-Ascorbic Acid: In the final step, add the L-Ascorbic Acid powder. Mix gently but thoroughly until it is completely dissolved. Adding it last helps minimize its exposure to water and air during the mixing process, which can help with stability.
7. Final Check: Perform a final pH check. Minor adjustments can be made carefully if needed, but significant changes after adding L-Ascorbic Acid should be avoided.

Recommended pH

The optimal pH range for a serum containing L-Ascorbic Acid and Lactic Acid is typically between 3.5 and 4.0.

• L-Ascorbic Acid is most effective and stable in acidic conditions, ideally below pH 4.0. The FDA requires cosmetic products applied to the skin to have a pH of at least 3.5.
• Lactic Acid also functions best as an exfoliant at a low pH, ideally below 4.0.

Maintaining the pH within the 3.5-4.0 range helps ensure the efficacy and stability of both L-Ascorbic Acid and Lactic Acid while complying with regulatory guidelines for cosmetic products.