Home Cosmetic Science Talk Formulating Why is my foundation formula separating?

  • Why is my foundation formula separating?

    Posted by Unknown Member on February 21, 2024 at 1:20 pm

    I’m trying to make a comfortable wear, dewy foundation using the Kobogel light I inherited from a friend who got it as a sample and couldn’t use it, and it’s just seemingly not very compatible with the formulae I’ve tried.

    This is the formula:


    Cetearyl alcohol, ceteareth-20 (4.5)

    SynKos 2050 (3)

    Lauryl laurate (2.5)

    Kester Wax K-82 (0.6)

    Cyclomethicone (3)


    Water (57.8)

    Glycerin (3)

    Xanthan gum (0.8)

    Optiphen (1.5)


    diphenylsiloxy phenyl trimethicone (5)

    Chione SVA (1)

    KoboGel (to 100)

    (Kobogel contains TiO2, iron oxides, Isododecane, isohexadecane, and lecithin)

    Method: combine A and heat to 85C. Combine B and heat to 85C

    Combine C

    Add C to B, keeping hot

    Add BC to A under propellor stirring, slowly cooling. At 65C, homogenize under high shear for 60 seconds.

    It’s doing this weird separation thing. The homogenizing did bring it together visually (it had looked like a broken emulsion initially), but when I rub the foundation on skin, it breaks dramatically right away, leaving water phase and spots of thicker o/s phase that have to be rubbed in after the water phase. Should I have done the emulsion more slowly? Or is there an incompatible ingredient in there? Can it be saved? Thanks!

    ketchito replied 2 months ago 2 Members · 1 Reply
  • 1 Reply
  • ketchito

    February 22, 2024 at 7:21 am

    Disregarding the issues formulators have using Optiphen in emulsions, you also have more than 3% of waxes, and they are hard to emulsify. Also, 0.8% of xanthan gum can gel your water phase which can also disbalance your emulsion. I’d replace your two waxes by some cetearyl alcohol (1-2%), and reduce the xanthan gum to around 0.3%.

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