Formulation Review and Recommendations

Here is a review of your serum formulation:

Compatibility

The ingredients in your formula are generally compatible for creating an oil-in-water serum using Silky Serum Base Plus. The water-soluble ingredients (Double Hyaluron Liquid, Panthenol, Safe-B3) can be dissolved in the water phase, and the oil-soluble ingredients (Retinal, Vitamin E, Shea Butter Light Oil) can be combined with the Silky Serum Base Plus in the oil phase. The total oil phase percentage is within the recommended range for the Silky Serum Base Plus.

Viscosity

Based on the proportions of water, oil phase, Double Hyaluron Liquid, and Silky Serum Base Plus, the resulting serum is expected to have a moderate to thick viscosity, likely feeling like a thicker serum or a light cream rather than a thin liquid.

Mixing Steps

The general steps of creating a water phase, an oil phase, emulsifying them, and adding the preservative at the end are correct. However, there are a few points to refine based on the specific ingredients:

• Retinal: The description for Retinal recommends avoiding heat if possible, as heat can cause it to deteriorate. Instead of using heat to dissolve Retinal, try dissolving it in the oil phase at room temperature. If heating the oil phase is necessary for other ingredients, add the Retinal after the oil phase has cooled down before combining it with the water phase.
• Emulsification with Silky Serum Base Plus: The description for Silky Serum Base Plus suggests adding the water phase slowly to the oil phase (containing the base) while stirring or blending. Adding the water phase all at once can make it harder to form a stable emulsion, especially without a high-speed blender.
• Preservative Addition: Ensure the temperature of the mixture is below 60°C when adding Phenoxyethanol SA, and that the final pH of the serum is within the effective range of the preservative (pH 2.0-6.0). The pH should also be suitable for the other actives, particularly Retinal (pH 3.5-6.5) and Safe-B3 (optimal pH 4.0-7.0). Aiming for a final pH between 3.5 and 6.0 would be ideal.

Recommended Adjustments

To improve the stability and efficacy of your serum, consider the following adjustments:

• Retinal Stability: Retinal is sensitive to light and oxidation. While Vitamin E offers some antioxidant protection, it is highly recommended to include a dedicated stabilizer for Retinal, such as Protec™ OX, UV, SQ, or Bakuchiol, as suggested in the Retinal product description. This will help maintain the potency and shelf life of the Retinal.
• pH Adjustment: Check the pH of your final serum and adjust it to be within the optimal range (ideally 3.5-6.0) for the stability and effectiveness of Retinal, Safe-B3, and the preservative.
• Formula Stability: The Silky Serum Base Plus description recommends adding 1-2% Magnesium Sulfate to the water phase to help improve the stability of the emulsion and prevent separation. Consider adding this to your formula.
• Mixing Technique: Follow the recommended mixing technique for Silky Serum Base Plus by slowly adding the water phase to the oil phase while stirring.

By making these adjustments, you can create a more stable and effective serum formulation.