Understanding the White Clumps in Your Cream Formulation

The white clumps you observed in your cream formulation, which dissolve upon rubbing, are likely due to MSH White (Undecylenoyl phenylalanine) precipitating out of the emulsion. While MSH White is soluble in the heated oil phase, it appears to be losing its solubility or failing to remain stably dispersed when introduced into the cooler water phase and the final emulsion structure.

Here's a breakdown of the likely causes and how to address them:

Potential Causes

1. MSH White Solubility and Temperature Shock: MSH White requires heat (at least 60°C, you used 80°C which is sufficient) to dissolve in oil. When this heated oil phase is added to the cooler water phase, the rapid temperature drop can cause the MSH White to crystallize or precipitate before the emulsion fully forms and stabilizes it. Although it dissolves on skin due to body heat and rubbing, it indicates instability in the cream matrix itself.
2. Emulsification Method: Satin Cream Maker is a cold-process emulsifier designed to be added to the water phase first, followed by the oil phase. Introducing a hot oil phase into a cooler water phase containing the emulsifier, even if the emulsifier is heat-tolerant, can disrupt the formation of a stable emulsion and lead to dispersion issues with solid components like MSH White.
3. Satin Cream Maker Concentration: While 1% Satin Cream Maker is within the recommended range for your total oil content (6%), the presence of a solid active like MSH White at 2% in the oil phase might require a slightly higher emulsifier concentration for robust stability and dispersion.
4. pH of the Final Formulation: The description for MSH White suggests optimal stability at pH 4-5, although it's soluble at higher pH. The final pH of your cream could potentially affect the long-term stability and solubility of MSH White within the emulsion.

Recommendations to Prevent Clumping

To achieve a smooth, uniform cream, consider adjusting your process:

1. Adjust Mixing Temperature and Method:
   • Try bringing both the water phase (containing Satin Cream Maker and water-soluble ingredients) and the oil phase (containing Safflower Seed Oil and dissolved MSH White) to a similar temperature, ideally around 70-75°C, before slowly adding the oil phase to the water phase while stirring continuously. This minimizes temperature shock.
   • Alternatively, follow the recommended method for Satin Cream Maker: Add Satin Cream Maker to the water phase and mix well. Then, slowly add the heated oil phase (with dissolved MSH White) to the water phase while mixing. Ensure continuous and adequate mixing during the addition and cooling phases to properly form the emulsion.
2. Increase Satin Cream Maker: Consider increasing the concentration of Satin Cream Maker slightly, for example, to 1.5%, to provide stronger emulsification and better suspend the MSH White particles.
3. Optimize MSH White Dissolution: Ensure the MSH White is completely and clearly dissolved in the Safflower Seed Oil at 80°C before combining the phases.
4. Verify Final pH: After the cream has cooled, measure the pH. If it's outside the optimal range of 4-5 for MSH White and Phenylethyl Resorcinol, carefully adjust it using a suitable acid or base, ensuring compatibility with all ingredients.
5. Consider Adding MSH White Post-Emulsification: Although the description suggests dissolving in oil, if the clumping persists, you could explore if MSH White can be effectively dispersed into the finished cream after emulsification and cooling, perhaps as a pre-dispersion in a small amount of a compatible solvent or oil, although this may affect stability.

By carefully controlling the temperature during mixing and ensuring adequate emulsification, you should be able to prevent the MSH White from precipitating and achieve a smooth, stable cream.