Oil Soap Formulation Issues: Rancidity, Salicylic Acid, Hyaluronic Acid, pH, and Odor Masking

Asked by: best_singnontad On: November 13, 2017 Product Type: Cosmetics

Question

I am developing an oil soap formulation and have some questions regarding specific ingredients and adjustments:

  1. I plan to use several natural oils in the formula. Will oils like Avocado Oil, Cherry Seed Oil, and Flaxseed Oil cause issues with rancidity?
  2. I want to include Salicylic Acid (Ingredient #5). How should I incorporate it into the oil base to ensure it dissolves properly?
  3. I also plan to add Hyaluronic Acid (Ingredient #6). Will this ingredient provide any benefit in a wash-off product like liquid soap, or should it be removed?
  4. To adjust the pH to 5, I plan to use Glycolic Acid + Water (Ingredients #10 + #11). I estimated needing around 3.5% of Glycolic Acid. Is this percentage correct, or is a much lower amount needed?
  5. To mask the rancid smell from the oils, I thought about using Melon Flavor. Will this be effective, or should I use a fragrance or essential oil instead? Are there other recommended odor masking agents like Citromask?

Answer

Based on the staff's response regarding your proposed oil soap formula:

  • Certain oils like Avocado Oil (#91), Cherry Seed Oil (#1249), and Flaxseed Oil (#1319) are prone to developing rancid odors over time.
  • For Salicylic Acid, it is recommended to use the liquid, timed-release version (e.g., #1372, #229) to ensure it dissolves properly in the oil base.
  • Hyaluronic Acid (#1351, #189) is not expected to provide significant benefits in a wash-off product like soap because it is rinsed off before it can effectively absorb or coat the skin. The staff recommends removing it from the formula.
  • To adjust the pH to 5 using Glycolic Acid (#660), a very low concentration is likely needed, estimated around 0.1-0.2%, not 3.5%.
  • To mask the rancid smell from the oils, you should use a fragrance (น้ำหอม) or essential oil. Melon Flavor is not suitable as it is a flavor and not strong enough to mask the odor. The staff also suggested trying Citromask (#1501), which helps mask odors and can also help reduce body odor when used in a wash-off product.