Home Cosmetic Science Talk Formulating Cetyl PEG/PPG-10/1 Dimethicone

  • emma1985

    November 6, 2020 at 5:24 pm

    I highly recommend reducing oil phase to 17-18% if you want to avoid adding high melting point wax. Look at Evonik’s formulas, the only one with high oil phase has like 3% of high melting point waxes. That kills the texture completely (although it’s obviously makes it more stable). 1.5-2% Abil EM90, 0.5-0.75% Isolan GPS, 1-1.5% of either NaCl, or Mg Sulfate or Zn Sulfate (a must! for stability). If you use sodium lactate of Sodium PCA reduce salt to 1% but don’t remove it. Now, if it’s a cold process and you want a lighter gel like texture use Zn Stearate at 0.5-0.7% and something like hydrated silica or silica dimethyl silylate (sold in Italy and Greece) and keep Dimethicone at less than 20%. If its a hot process you can up oils but follow what Evonik suggested in the formula with 40% of oils where they added tons of waxes. It’s going to have long rheology and will be runny. You can try both options and see which you like best. And which one is more stable. W/Si are tricky beasts.

    Thank you so much!! This is incredibly helpful. I’m not ready for W/Si yet so I’ll stick with W/O with 17-18% oil phase.

    I will use 1.5% Abil EM90, 0.75% Isolan, 1% Magnesium Sulfate and 1% each of Sodium Lactate and PCA. Per your instructions.

    I found some USP Magnesium Sulfate, hope that will work fine (sold as Epsom Salt.)

    I will be heating the oil phase but not the water phase as discussed in my original post, per provided sample formulations.

    Thanks again!!

  • bill_toge

    November 7, 2020 at 6:40 pm
    hydrogenated castor oil gels the oil phase and makes it non-fluid at rest, which helps stabilise W/O emulsions
    magnesium sulphate increases the surface tension of the water phase, reducing the tendency of individual droplets to aggregate, also increasing the emulsion stability
    forming a W/O emulsion is working uphill against the laws of thermodynamics - you have to take as many advantageous measures as you can
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