Troubleshooting Cloudiness in Surfactant and Zinc Ricinoleate Solution

Question

I would like to ask how to resolve a cloudiness issue in a solution. The ingredients were mixed into water at room temperature in the following order:

Sodium Laurylglucosides Hydroxypropylsulfonate 3.5 mL
Decyl Glucoside 2.5 mL
Cocamidopropyl PG-Dimonium Chloride Phosphate 0.5 mL
Soyethyl Morpholinium Ethosulfate 1 mL
Zinc Ricinoleate (30% Solution) 1 mL

The resulting solution is turbid. How can I fix this problem?

MySkinRecipes Expert · Accepted Answer

The cloudiness in your formulation is likely caused by two main factors: the interaction between anionic and cationic surfactants and the solubility requirements of Zinc Ricinoleate. Potential Causes Surfactant Incompatibility: You are mixing Sodium Laurylglucosides Hydroxypropylsulfonate (anionic) with Soyethyl Morpholinium Ethosulfate (cationic). These oppositely charged molecules can form a complex that is insoluble in water, leading to turbidity or precipitation. Zinc Ricinoleate Solubility: Zinc Ricinoleate (30% Solution) often requires a solubilizer and a specific pH range (typically 7.5–11) to remain clear in an aqueous system. pH Level: Decyl Glucoside has a very high pH (around 11.5). If the overall pH of the formula is not properly balanced, it can affect the clarity and stability of other ingredients. Recommended Solutions Use a Solubilizer: To achieve a clear solution, especially when using Zinc Ricinoleate, it is highly recommended to add a solubilizer such as Ultra Solve (PEG-40 Hydrogenated Castor Oil). Add Glycols: Adding Propylene Glycol or Butylene Glycol (around 5-10%) can help improve the clarity and stability of the mixture. Adjust the Mixing Order: Step 1: Mix Zinc Ricinoleate (30% Solution) with the solubilizer (Ultra Solve) and glycols first. Step 2: Dissolve this premix into the water. Step 3: Add Decyl Glucoside and Cocamidopropyl PG-Dimonium Chloride Phosphate. Step 4: Slowly add the remaining surfactants. Check and Adjust pH: Ensure the final pH is within the stable range for Zinc Ricinoleate (7.5–11). If the formula needs to be more skin-friendly (pH 5.5), you may need a different form of Zinc Ricinoleate or accept a cloudy appearance. Chelating Agent: Adding Disodium EDTA (0.1%) can help stabilize the formula and maintain clarity. What I need from you to confirm: What is the final pH of your current mixture? Are you aiming for a completely water-clear product? Do you have a solubilizer available in your current inventory?