Answer to Questions about Serum Formulation

Here are the answers to your questions regarding serum formulation, based on product information and recommendations:

1. Adding Fragrance to Silky Serum Base:

   • You can add fragrance oil directly to Silky Serum Base.
   • However, it should be added in a very small amount, not exceeding 1% of the total formula.
   • This is because Silky Serum Base (such as Silky Serum Base or Silky Serum Base Plus) is not designed to effectively emulsify oils, and most fragrances are oils. Adding too much can cause the formula to separate.
   • If your formula contains a significant amount of oil, you should consider using Silky Serum Base Plus, which has better oil-emulsifying capabilities.

2. Calculating EDTA Percentage:

   • The recommended usage rate of 0.2% for Disodium EDTA is indeed 0.2% of the distilled water portion, or the total water phase, in the formula.
   • Disodium EDTA acts as a chelating agent, binding to metal ions in water to prevent them from interfering with other ingredients and to enhance formula stability.

3. Using EDTA with Green Tea Extract and DI Water:

   • Theoretically, if you are using Green Tea Extract and highly pure DI water, adding Disodium EDTA might not be strictly necessary.
   • However, in practice, the absolute purity of the water used cannot always be guaranteed.
   • Adding a small amount of Disodium EDTA (0.1-0.2%) provides added assurance for formula stability and helps prevent potential metal ions in the water from affecting other ingredients, such as Green Tea Extract, which can be sensitive to certain metal ions.
   • Therefore, even when using DI water and including Green Tea Extract in your formula, it is still recommended to consider adding Disodium EDTA for maximum stability.

Hope this information is helpful for your formulation work.