15% Water added in Cooldown Phase, Separates @ 40c

Hi all,

I have a formula that is very stable at room temperature. But 15% of another material, mostly water, is added to the product afterwards.
When put into a pump and raised to 40c, the water that was added to the formula separates and leaks.

What do you recommend to have higher stability when heated?

Details on the formula:

Emulsifying System:
Emulsifying Wax NF (Cetearyl Alcohol, Polysorbate 60/ CAS 9005-67-8)
Cetyl Alcohol

Water 32%
Aloe Vera Liquid 15%
Glycerin 3%

Avocado Oil 6%
Menthol 2.5%
Sweet Almond Oil 6.5%
Emulsifying Wax NF 5%
Cetyl Alcohol 3%
Shea Butter 6%
Cocoa Butter 1%
Perservative 1.5%
Extracts/Marketing 3%
Tocopherol 0.5% 

Then 15% of a water-based material is added after many days later when the product is cooled.... and that seems to be fine, but when heated to 40c, separation occurs and the product leaks.

After doing a lot of research, water phase thickeners seem to be an idea.

Any other ideas or specifics on the best way to compliment this formula to provide higher stability at increased temperatures?

Thank you!



  • Hi all,

    A quick update. It seems as though the product is completely separating at 40~c. (Not just the 15%).
  • I’ve heard people say that you cannot add more than 10% liquids to an emulsion after it’s cooled down and emulsified.

    How sensitive are the ingredients you’re adding? And what are they exactly? are they electrolyte rich? Why not add them in the cool down phase at or below 40C? A full formulation would be ideal to get good feedback.

    Usually you will want a gum or polymer in your dispersed phase which will help stabilize your emulsion, basically by slowing down coalescence. 0.1-0.5% Xanthan Gum of your total formulation would be enough. I do 0.3% for a lotion with 70% water.

  • Thanks @letsalcido,

    Extra info: Because of the smaller volume in R&D, these samples are being agitated by a stick blender.

    Do you think the extra 15% added post-formulation could result in the entire water/oil phase separation?

    I am trying to isolate whether the formula breaks on its own at 40c because of lack of a water phase thickener like Xanthan Gum, or because the 15% was too much and broke the entire emulsification system.

    I don't believe the 15% substance is rich in electrolytes. It's mainly water, with a small percent of an oil extract. (It's its own emulsion).

    They can't be added in the cooldown phase due to legality of where the original cream is originating, and where it's being sent and having that 15% added.

  • EVchemEVchem Member
    Aloe Vera Liquid 15% is quite a bit and usually has its own electrolytes to complicate things.

    If you're going to post add 15% I'd recommend using some polymeric emulsifiers rather than traditional waxes. You could try anything from carbomer (though it's in short supply rn), sepimax zen, sepiplus 400, aristoflex avc, etc. Personally I wouldn't trust a gum for this situation.
  • @EVchem, that sounds like a good idea. Would you recommend keeping my existing waxes at their current levels, but replace some water phase with the polymeric emulsifiers?

    Would adding much more Polysorbate 60, for example, help with this? I am going to do a lot of testing.
  • edited August 2020
    Hi all,

    A quick update. I did about 6 samples so far. The best so far has been Xanthan Gum at 0.5%, with PEG-40 at 3% to assist with emulsion.

    Still doing some heat studies... there are some very specific heat requirements due to the geographic area where the product is going and the storage conditions.

    HEC did quite well, but Xanthan Gum did better. I tried combining the two but XG and PEG-40 have worked the best so far. It passed the initial 40c tests and moving forward to higher temperatures.

    Thanks for your assistance, I will be posting photographs of the different samples and separations to assist anyone else who may have this issue in the future.


    PS The pH is quite low (in the 3's/4's). Do you think this could be contributing to the separation?
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