Troubleshooting Serum Formulations: Yellowing in Water-Based and Separation in Silicone Serum

Asked by: at.leonidas.37 On: May 19, 2014 Product Type: Cosmetics

Question

I have two serum formulations that are experiencing issues and would like advice:

  1. Water-based serum that turned yellowish: My serum with a water base has turned a light yellowish color. The formula contains ingredients like Ferulic acid and a lotus fragrance. I've been advised that Ferulic acid is not water-soluble and the fragrance (possibly containing vanillin) might cause the color change. I am concerned about the stability and efficacy of the product.
  2. Silicone serum that separated: My silicone serum has separated into layers. The formula includes silicone gel, dimethicone, isododecane, IPM, and water-based extracts (Delentigo, Nanowhite, tomato extract). I understand this is likely due to the lack of an emulsifier. I received advice to use SiliSolve at 1.5-2.0% by mixing it with the silicone/oil phase (silicone gel, dimethicone, isododecane, IPM) first, then combining with the water phase (extracts). It was also suggested to consider removing IPM or replacing it with cyclomethicone as IPM is an oil and might complicate emulsification.

Could you confirm the causes of these issues and the suggested solutions?

Answer

Based on the conversation provided, here is a summary of the issues and advice for your two formulations:

Formulation 1: Water-based serum that turned yellowish

  1. Undissolved Ferulic Acid: As the staff mentioned, Ferulic acid is not water-soluble and requires a solvent like ethoxydiglycol. It likely did not dissolve properly in your formula, contributing to instability or color change.
  2. Fragrance: User C7 suggested that the fragrance, especially if it contains vanillin compounds (even in a lotus scent, depending on its composition), can cause yellowing over time.
  3. Efficacy: The color change indicates instability. While the color itself might be harmless, the underlying reactions causing it could potentially affect the long-term efficacy and stability of other ingredients. The undissolved Ferulic acid is not effectively active.
  • Recommendations for Formulation 1:*

  • Remove the Ferulic acid or filter it out.

  • If using Ferulic acid, reformulate with a suitable solvent.
  • Consider if the fragrance contains vanillin notes.

Formulation 2: Silicone serum that separated

  1. Lack of Emulsifier: User C7 explained that separation occurs because there is no ingredient to emulsify the silicone/oil phase with the water-based ingredients.
  2. Recommended Solution: Use SiliSolve at 1.5-2.0% as an emulsifier. Mix SiliSolve with the silicone/oil phase first, then combine with the water phase.
  3. IPM: C7 suggested removing IPM temporarily as it might complicate emulsification. Cyclomethicone was suggested as an alternative.
  • Recommendations for Formulation 2:*

  • Incorporate SiliSolve (1.5-2.0%) as an emulsifier.

  • Follow the recommended mixing method.
  • Consider removing IPM or replacing it with cyclomethicone.

Regarding SiliSolve availability, I do not have access to real-time stock information.