Troubleshooting Ethylcellulose (100 cps.) Dissolution in Lip Jelly

Thank you for reaching out regarding the issue with dissolving Ethylcellulose (100 cps.) in your lip jelly formulation. It sounds frustrating to have undissolved particles even after heating for so long.

Based on the properties of Ethylcellulose (100 cps.), it is an oil thickener designed to dissolve in polar oils and ethanol when heated to 70-85°C. The recommended method is to first disperse the powder thoroughly in the oil at room temperature, and then heat the mixture until it becomes clear.

Given that you heated to 85-90°C for 3 hours and still have undissolved particles, here are the most likely reasons and how to address them:

1. Oil Type: Ethylcellulose requires a polar oil to dissolve properly. If you are using a non-polar oil (like mineral oil, squalane, or pure hydrocarbons), it will not dissolve correctly, regardless of heat or time. Ensure the oil phase of your lip jelly uses polar oils (e.g., Caprylic/Capric Triglyceride, ester oils, castor oil).
2. Dispersion Before Heating: It is crucial to fully disperse the Ethylcellulose powder in the oil before applying heat. If the powder is added to hot oil or not fully dispersed initially, the outer layer can gel or clump, preventing the heat and oil from reaching the inner particles, leading to undissolved lumps.

Recommendations:

• Check your oil phase: Confirm that the primary oils used are polar and suitable for dissolving Ethylcellulose.
• Improve dispersion: In your next attempt, add Ethylcellulose (100 cps.) to your oil phase at room temperature. Stir or mix vigorously until the powder is completely wetted and evenly dispersed with no visible dry clumps before you begin heating.
• Heat correctly: Once dispersed, heat the mixture to the recommended 70-85°C and maintain the temperature while stirring until the mixture turns clear. The time required depends on the batch size and stirring efficiency, but once clear, it should be fully dissolved.

Your usage rate of 5.5% is within the recommended range (0.5-20%), so the concentration itself is unlikely to be the primary issue if the oil type and dispersion are correct.

For the current batch with undissolved particles, it might be difficult to fully salvage, but you could try reheating it after ensuring it is thoroughly dispersed, focusing on the 70-85°C range. However, for best results, preparing a new batch with proper oil selection and dispersion technique is recommended.

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