Home Cosmetic Science Talk Formulating how to change o/w to w/o?

  • how to change o/w to w/o?

    Posted by cherri on March 28, 2014 at 1:15 pm

    happy Friday everyone!
    quick question.. how do I change my o/w formula to w/o?
    I have water phase, oil phase, actives, and preservative.
    the original comes out as gel type white cream and I want to try w/o… any help?
    I used kappa, cetyl oh, wheat germ oil, ptc, stearyl oh, and my water phase is with xanthan gum.

    any help will be appreciated. thank you!

    chemist77 replied 9 years, 8 months ago 5 Members · 13 Replies
  • 13 Replies
  • chemist77

    March 28, 2014 at 1:23 pm

    kappa???? Carrageenan grade you mean???

  • Bobzchemist

    March 28, 2014 at 3:19 pm

    A complete formula with percentages would be needed before we could help you. INCI names would be useful too.

  • MakingSkincare

    March 28, 2014 at 7:34 pm

    cherri, here’s an article from a supplier - MakingCosmetics.com:-


    You will want to make quite a few changes to your formula incl using a low HLB emulsifier and add epsom salt to stabilize etc
  • cherri

    March 31, 2014 at 9:18 am

    GLYCERIN @ 3%
    XANTHAN GUM @ 0.3%
    SHEA BUTTER @ 3%
    SOY BEAN OIL @ 5%

    I switched from emulium kappa to montanov 68… so how do I change o/w to w/o? any help will be appreciated thanks so much!

  • chemicalmatt

    March 31, 2014 at 10:09 am

    Before you get too far using that article linked from makingcosmetics.com, cherri, be advised there are glaring misrepresentations in that article about inverse-phase emulsions. Do not add polymeric thickeners to the internal (water) phase - ever - unless you really want to drive yourself crazy. I don’t know where they came up with that one, but it is categorically wrong. (Who writes this stuff?) Also, magnesium sulfate works better than NaCl in stabilizing W/O emulsions about 90% of the time, so start with epsom salt always.  That article also fails to mention the best W/O emulsifiers in existence, the silicone-based ones.  See Evonik, Siltech and Dow-Corning product guidelines for these. In case you haven’t deduced this yet: you have to begin from scratch here; you cannot simply “change” from O/W to W/O.

  • chemist77

    March 31, 2014 at 11:32 am

    @Cherri I agree with chemicalmatt, totally clueless how to change this one to w/o but yeah if you start from scratch and wanna some help on w/Si emulsion then let me know DC have some very good w/Si emulsifiers though I have used NaCl to thicken my formula. As per the crazy request of customer I had to incorporate 3% perfume oil as well into this formula and it came out wonderful.

  • Bobzchemist

    March 31, 2014 at 11:38 am

    You may not have to start “completely from scratch - but you can’t keep all that much of your original formula either:

    Phase A
    ABIL® EM 90 2.0 % 
    Behenyl Alcohol 0.5 % 
    Cetyl Alcohol 0.5 % 
    Shea Butter 3.0%
    Soybean Oil 10.5 % 
    Wheat Germ Oil 5.0 % 
    Cyclomethicone 6.0 % 
    Tocopheryl Acetate 0.5 % 
    Phase B
    Magnesium Sulfate 0.5 % 
    Glycerin 3.0 % 
    Water 63.5 % 
    Phase C  
    Alcohol 5.00 % 
    Preservative, Parfum q.s. 
    -Heat Phase A and B to at least 70C
    -Homogenize A and B for 20 minutes
    -Cool to 50C
    -Add Phase C and then anchor mix to RT
    You could say that you “changed” from a o/w to a w/o - or you could say that you started over.
    Either way, what you had to do was:
    1. Remove all water phase thickeners
    2. Remove all o/w emulsifiers and emulsion stabilizers
    3. Use a w/o emulsifier
    4. Increase oil phase
    5. Add magnesium sulfate
  • MakingSkincare

    March 31, 2014 at 1:51 pm

    Some great advice here.

    Bob - I see you added 5% alcohol??
  • Bobzchemist

    March 31, 2014 at 2:24 pm

    It was in Evoniks starting formula…

    But it’s not needed for the formula, it’s just in there for skin feel and possibly to assist the preservative, as far as I can tell.
    And I left out that you have to start out homogenizing Phase A and slowly add the water.
  • MakingSkincare

    March 31, 2014 at 2:45 pm

    Ah, that explains it, I was wondering where the 5% alcohol had appeared from!!

    If only homogenizers were cheap - I know w/o really needs it.  cherri do you have access to one??

  • Bobzchemist

    March 31, 2014 at 4:27 pm

    How cheap do homogenizers need to be?

  • cherri

    March 31, 2014 at 6:18 pm

    @Bobzchemist, chemicalmatt, milliachemist , MakingSkincare thanks all for your help.

  • chemist77

    March 31, 2014 at 9:59 pm

    @Bobz does the addition of water need to be slow and in parts as needed for W/Si emulsion? Because you mentioned homogenization so I am guessing all at once.

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