Mixing Instructions for Your Serum Formula

Hello,

Here is a suggested method for mixing your serum formula, taking into account the specific requirements of Ascorbyl Glucoside and Hydroxyethylcellulose:

Mixing Procedure

1. Prepare the Water Phase (Heated): Take about 75% of the total water (approximately 60.75g if making 100g) and heat it to around 70°C.
2. Disperse Hydroxyethylcellulose: Slowly sprinkle the Hydroxyethylcellulose (3g) into the heated water while stirring continuously with a mixer until it is fully dispersed and starts to form a gel. Continue stirring while the mixture cools down.
3. Dissolve Allantoin: In a separate small container, take a portion of the remaining water (e.g., 5g) and heat it slightly to help dissolve the Allantoin (0.5g). Once dissolved, add this solution to the main water/HEC phase when it has cooled below 75°C. Continue stirring.
4. Prepare Ascorbyl Glucoside Solution: In the remaining water (approximately 15.25g), dissolve the Ascorbyl Glucoside (10g). It is highly recommended to first add a pH buffer like L-Arginine (at a ratio of 1 part L-Arginine to 2 parts Ascorbyl Glucoside, e.g., 5g L-Arginine for 10g Ascorbyl Glucoside - Note: L-Arginine is not in your formula, you would need to add it or use a Citrate Buffer as mentioned in the Ascorbyl Glucoside description. If you don't add a buffer, the pH will drop very low initially, which can degrade the Ascorbyl Glucoside.). Add the Ascorbyl Glucoside to this buffered water and stir until dissolved.
5. Combine Phases: Once the main water/HEC/Allantoin phase has cooled below 50°C, add the Ascorbyl Glucoside solution. Mix thoroughly.
6. Add Sodium Lactate and Lactic Acid: Add the Sodium Lactate (3g) and Lactic Acid (5g) to the mixture and stir well.
7. Adjust pH: Measure the pH of the final mixture. Ascorbyl Glucoside is most stable at pH 6.5-6.8. Lactic Acid is most effective below pH 4.0. Your formula combines a high percentage of both, which have conflicting optimal pH ranges. Sodium Lactate will provide some buffering. To ensure the stability of 10% Ascorbyl Glucoside, it is recommended to adjust the final pH to the range of 6.5-6.8 using an alkali solution (such as Triethanolamine or Sodium Hydroxide solution). Be aware that at this pH, the exfoliating effect of Lactic Acid will be significantly reduced. If you prioritize the exfoliating effect of Lactic Acid, you would need to target a lower pH (below 4.0), but this will compromise the stability of Ascorbyl Glucoside. You may need to decide which active is more important for your desired product outcome or consider adjusting the concentrations.
8. Add Preservative: Once the mixture has cooled below 60°C, add the Phenoxyethanol (0.5g) and mix until fully incorporated.

Potential Adjustments

• Concentrations: The concentrations of Ascorbyl Glucoside (10%) and Lactic Acid (5%) are quite high, especially in combination. This might cause irritation, particularly for sensitive skin. You might consider reducing one or both concentrations.
• Hydroxyethylcellulose: 3% HEC will create a very thick gel. If you prefer a lighter texture, you can reduce the percentage of HEC.
• pH Conflict: As noted in the mixing steps, the optimal pH for Ascorbyl Glucoside stability (6.5-6.8) and Lactic Acid efficacy (below 4.0) are different. You will need to decide on a target pH based on the primary function of your product. Adjusting to 6.5-6.8 favors Ascorbyl Glucoside stability, while a lower pH favors Lactic Acid exfoliation but risks Ascorbyl Glucoside degradation.
• Buffering for Ascorbyl Glucoside: As mentioned in step 4, using a buffer like L-Arginine or Citrate Buffer when dissolving Ascorbyl Glucoside is highly recommended to prevent degradation during the initial acidic phase.

Always perform a small test batch first to ensure compatibility and desired texture.