Emulsion Instability question

DungngoDungngo Member
edited November 20 in Formulating
Hi everyone

I created this moisturizer 2 days ago. The cream texture seemed fine and smooth at first so I put them into jars ,closed the lid and left them at room temperature (75 F) for 2 days . After 2 days, I opened the jars and the texture seems like foam. Anybody experienced this before and know how to fix ? I was blending quite carefully but no idea why the texture changed within 2 days. I know the emulsion got problem with stablity but couldn't figure out why. I was blending using hand blender and homogenizer for 30-40 mins. Below is my formula and pictures :
Formula : 
Water 34.8%
Rose hydorsol 10%
solagum AX 0.3%
glycerin 1%
Sodium gluconate 0.1%
Potassium sorbate 0.2%
Sodium pca 4%
Olivem 1000 8%
Cetyl Alcohol 3%
Shea butter 10%
Isopropyl Myristate 5%
Squalene 4%
Olive oil : 4%
Sea buckthorn oil : 1%
Bisabolol 1.5%
Colloidal oat powder 2%
Honey powder 2%
Sepilift 2%
Tetrapeptide 2%
Vit E 0.6%
Urea 1%
EO Ylang Ylang 1%
Geogard ECT 1%
pH adjustor 1%

I boil water+ gum+ +glycerin , stir, then add rose hydrosol, sodium,potassium to finish water phase, then boil olivem+shea butter+ cetyl alcohol, blend them with water phase above , stir and homogenize, then add isopropyl,squalene,oils,bisabolol,colloidal,honey, then blend and homogenize them again, then add sepilift,tetrapeptide,vit E, urea, EO and preservative and pH adjustor. Blend and homigenize. 
2 days later ( Day 3), the emulsion becomes instable like this


Comments

  • Bill_TogeBill_Toge Member, Professional Chemist
    it looks like a lot of air was trapped within it during the manufacturing process, and it's now starting to come out
    high-shear mixing is best kept to the absolute minimum necessary to form the emulsion, and it's best to keep the head of the mixer entirely below the surface of the liquid, or else you end up with problems like this
    UK based formulation chemist. Strongest subjects: hair styling, hair bleaches, hair dyes (oxidative and non-oxidative) I know some stuff about: EU regulations, emulsions (O/W and W/O), toothpaste, mouthwash, shampoos, other toiletries
  • Thanks Bill_Toge. Question : Should I limit the times of switching between homogenizer and blender ? Like do all the blending first and homogenizing later then I can limit the air trap problem ? And do you know if there is any way I can save this batch ? Thanks !
  • You can increase the batch size.

    What size do you make now and what homogenizer?

    If using stick blender the head should never come out of the liquid
  • @Dungngo Why don't you add isopropyl myristate, squalene, oils and bisabolol as part of your oil phase? In that way, you could homogenize only once which would also reduce the aeration. After homogenizing, the mixing should be reduce (this will also help you get rid of part of the air) 'till you finish your batch.
  • A few things.....

    Is Olivem 1000 enough to emulsify that large of an oil phase? Why not use Glyceryl Stearate & PEG 100 Stearate or some other emulsifier or co-emulsifier..?

    Also, is Geoguard enough to preserve the hydrosol, colloidal oatmeal powder and honey powder...? Those can be some pretty tasty bug food and can be difficult to preserve effectively, especially with "natural" preservatives...

    What PH Adhuster are you using at 1%? Seems a bit high to me ..🤷‍♀️
  • Abdullah : My batch size is 300 grams. I use this homogenizer : 
  • DungngoDungngo Member
    edited November 22
    Ketchito : Yeah I am gonna add them into oil phase to reduce the times of switching between blender to homigenizer. I was trying to make sure that all is blended well , that's why I blend just a few ingredients first. Btw, do you think the Olivem 1000 is too weak to emulsifier such high % of oil phase ( shea butter is up to 10%). I have never used such high % of shea butter in emulsion so I'm not quite sure if part of the problem comes from the emulsifier.

    Thanks
  • Abierose : I combine Olivem 1000 with Cetyl Alcohol. I thought Cetyl alcohol could help in stabilizing the emulsion a bit. I used to try Olivem 1000 with 25% oil phase ( all oils, no shea butter) and it worked just fine !. Since this time i used a lot of shea butter so I think I'm gonna switch it with other stronger emulsifier. Do you recommend any natural emulsifier that can handle 25% or more oil phase ? 
    Also for the preservative, I'm not sure if it can handle that much hyrosol + powder so I'll reduce them ! Thanks for noticing me !
    I used citric acid as pH adjustor and it reduces the pH to around 4.8 to 5. Not a fixed number as the pH keeps drifting. I don't know why pH keeps drifting though
  • Urea will cause drift.

    Does this product feel good to you?

  • Dungngo said:
    Ketchito : Yeah I am gonna add them into oil phase to reduce the times of switching between blender to homigenizer. I was trying to make sure that all is blended well , that's why I blend just a few ingredients first. Btw, do you think the Olivem 1000 is too weak to emulsifier such high % of oil phase ( shea butter is up to 10%). I have never used such high % of shea butter in emulsion so I'm not quite sure if part of the problem comes from the emulsifier.

    Thanks
    @Dungngo I agree with @abierose, try to switch from Olivem 1000 to something like Glyceryl Stearate & PEG 100 Stearate. Olivem 1000 might not be too adequate to give you a solid O/W emulsion with the types of oils you're using.
  • Urea will cause drift.

    Does this product feel good to you?

    Thanks ! Will take note of that. The moisturizer has a very smooth feel due to the shea butter I put it so I really like it.
  • @ketchito : Thanks ! I’ll try it !
  • Dungngo said:
    Urea will cause drift.

    Does this product feel good to you?

    Thanks ! Will take note of that. The moisturizer has a very smooth feel due to the shea butter I put it so I really like it.
    Interesting that you like the feel of Shea butter. I use it at 0.5% only because i have purchased 25kg of it and have to use it in some way. I will not purchase it again. 
  • Abdullah said:
    Dungngo said:
    Urea will cause drift.

    Does this product feel good to you?

    Thanks ! Will take note of that. The moisturizer has a very smooth feel due to the shea butter I put it so I really like it.
    Interesting that you like the feel of Shea butter. I use it at 0.5% only because i have purchased 25kg of it and have to use it in some way. I will not purchase it again. 
    I try NOW's shea butter. It's a bit different from regular shea butter. They bring about very smooth feel.
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