Home Cosmetic Science Talk Formulating Separation of W/O emulsions

  • Separation of W/O emulsions

    Posted by attapol on April 7, 2014 at 11:36 pm

    Hi everyone,

    I try to make the BB cream which is W/O emulsion but it was separation after 2 weeks.
    I found that the separation is the oil phase so I think my problem might be the oil compatibility issue.
    Can anyone suggest which oil or other reason cause of that?.
    My formula is below.
    Part A
    Iron oxide 0.85%
    Tio2  13 %
    Methyl Methacrylate Crosspolymer 3%
    Ethylhexyl methoxycinnamate 7%
    Cyclomethicone 6%
    cetyl peg/ppg-10/1 dimethicone  3%
    dimethicone/vinyl dimethicone crosspolymer 7%
    Ethylhexyl Stearate  6%
    diethylhexyl carbonate 5%
    peg-10 dimethicone  3%

    Part B
    Water -qs to 100%
    Sodium choride 1%
    Butylene glycol 7%
    Phenoxyethanol 0.5%
    Perfume 0.2%


    1. Mix phase A and heat to 70c
    2. Mix phase B and heat to70c
    3. Add 2 into 1 slowly ,
    4. cool down
    Thank in advance,
    chemist77 replied 9 years, 7 months ago 4 Members · 8 Replies
  • 8 Replies
  • bill_toge

    April 9, 2014 at 3:54 pm

    when mixing the two phases together, do you use a high-shear mixer (e.g. a Silverson, or a Greaves)?

    in my experience W/O emulsions separate or Ostwald ripen if they’re not sheared enough, regardless of how well formulated they are

  • chemist77

    April 9, 2014 at 10:03 pm

    @attapol Have you considered using coated pigments?? They are preferred in such kind of w/o emulsions.

  • attapol

    April 10, 2014 at 1:24 am

    Thank you @Bill_Toge , I used the propeller mixer when add water to oil phase and homogenizer  at 1000 rpm when cooling down. When cooling down ,cream is so viscous and little bit diffcult to homogenize.

    May be homogenize 1000 rpm is not enough?.
    @milliachemist Yes, I used the coated pigments in this formula.
  • chemist77

    April 10, 2014 at 9:35 am

    going through the ing list i feel u already have enough oil phase to keep the viscosity low, try increasing the emulsifier and cut down a bit on peg10 dimethicone, dont see much use of it here. Maybe it will bring down the viscosity, as for separation yes it might be incompatibility of oil or less quantity of emulsifier.

  • Bobzchemist

    April 10, 2014 at 11:28 am
    1st question: How many different emulsifier levels have you tried?


    You will probably need to homogenize right from the beginning, and cool down with an anchor mixer. There’s no need for a propeller mixer at all.

    The RPM should be set only by visual observation - you want a speed just a little bit lower than the speed that aerates the batch - faster is always better, everything else being equal. This will need to be adjusted as each individual batch progresses - don’t fixate on keeping the same speed all the time - that’s an easy route to many, many failed batches.
    You might also want to switch your first surfactant to Gransurf W9, but calculate the amount you use so that you keep the Cetyl peg/ppg-10/1 dimethicone level the same.
    Lastly, you may want to hold off on adding the Dimethicone/vinyl dimethicone crosspolymer and/or the Methyl Methacrylate Crosspolymer until after the emulsion is formed and the batch is starting to thicken.
  • attapol

    April 12, 2014 at 9:08 am

    Thank you @milliachemist  and @Bobzchemist . Never  adjust the emulsifier level and I will try that .

  • attapol

    April 28, 2014 at 10:29 pm

    Hi all,

    I just would like you all to know my result.
    After tries the few batches, now my formula is stable ( pass 5 cycles of freeze-thraw and 45c for 3 weeks).
    This is my experimental.
    Trial A : increase cetyl peg/ppg-10/1 dimethicone in Part A from 3% to 5% and decrease water in Part B 2%
    Result : Separation
    Trial B : eliminate peg-10 dimethicone from the formula and increase water in Part B 3%
    Result : No seperation , pass stability test
    Trial C : eliminate Ethylhexyl methoxycinnamate from the formula and increase water in Part B 7%
    Result : No seperation , pass stability test
    So my hypothesis is that the ethylhexyl methoxycinnamate is incompatible with peg-10 dimethicone.

  • chemist77

    April 28, 2014 at 11:03 pm

    @attapol I think when you share such results it is quite helpful for us as well, good going.

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