Home Cosmetic Science Talk Formulating Weak Emulsion

  • Weak Emulsion

    Posted by prow18 on April 6, 2021 at 7:21 pm

    Hi everyone, I’ve been working on a formulation and am having difficulty with the emulsion separating after going through stability testing. After a few heat/cools water will form at the bottom. Any help pointing me in the right direction would be appreciated! I’ve tried a bunch of different variations of emulsifiers and nothing seems to work… 

    Thanks in advance! 

    Batch Process: 
    Heat Water and Oil Phase to 180f and mix 3 minutes 

    Add cool down phase and mix another 3 minutes. 

    Mixer: Overhead propeller mixer 

    Water Phase
    Water 42.17%
    propylene glycol 3.33%
    Potassium Sorbate 0.82%
    pvp 1.09%
    pvp/va copolymer 8.76%
    Oil Phase
    Petrolatum 5.41%
    Oil Lanolin 3.83%
    Wax Lanolin 3.28%
    Cetyl Alcohol 2.47%
    Stearyl Alcohol 2.47%
    ozokerite 2.19%
    carnuba wax 3.00%
    Mineral Oil 1.96%
    Peg 40 castor oil 3.33%
    Steareth -21 3.59%
    PEG-7 Glyceryl Cocoate 2.48%
    Ceteareth 25 4.83%
    Lauryl Laurate 0.99%
    Cool Down Phase
    Fragrance 2.38%
    Phenoxyethanol 1.05%
    Citric Acid 0.56%
    Abdullah replied 2 years, 11 months ago 5 Members · 15 Replies
  • 15 Replies
  • singhc10

    Member
    April 7, 2021 at 11:52 am

    @prow18 is this a hair curl cream formula? Anyway, I recommend using a blend of ethoxylated emulsifiers, due to their oligomeric distribution they provide very stable emulsions. For example; use a blend like Steareth-2, Stereath-10 & Steareth-21, each at 2.5% in your case. This should do it

  • prow18

    Member
    April 7, 2021 at 12:05 pm

    @singhc10 - yes, it’s a hair styling formula. 

    I have Steareth-2 + Steareth-21 + Ceteareth-25 and have tried that combo, but it hasn’t yielded results.. 

    I’m stumped because this is a generally standard list of ingredients in mainstream products. Crew Uses this blend of emulsifiers, see blow ingredients (bis-diglyceryl polacyladipate-2 used by both) 

    Crew: D:Struct Crew: Forming Cream
    Water Water
    Petrolatum Petrolatum
    Cetearyl alcohol Cetearyl Alcohol
    Bis-Diglyceryl Polyacyladipate-2
    Steareth-21 lanolin wax
    Lanolin Wax steareth-21
    PVP pvp
    PVP/Va ceteraeth-25
    Propylene Glycol carnauba
    Carnauba propylene glycol
    Ceteareth-25 pvp/va
    Mineral Oil mineral oil
    Ozokerite ozokerite
    diethylhexyl malate diethylhexyl malate
    peg-40 castor peg-40 castor
    Alcohol denat Alcohol Denat
    peg-10 soy sterol peg-10 soy sterol
    sucrose sucrose
    fragrance parfum
    Glycerin benzyl saliclate
    Preservative Preservative
  • singhc10

    Member
    April 7, 2021 at 1:17 pm

    @prow18

    • Run a moisture analysis on Crew product. Compare your water content with the benchmark.
    •  Get a sample of Steareth-10, it has different oligomeric distribution than Stereath-2 and Stereath-21
  • prow18

    Member
    April 7, 2021 at 1:59 pm

    @singhc10 

    Unfortunately I don’t have the equipment for a moisture analysis. 

    Are you saying to use steareth-10 as a substitute for the peg-10 soy sterol? (Rather than the peg7 glyceryl cocoate used currently)

    I’m seeing other brands outside crew using this same combo of ceteareth-25, Steareth-21, and peg-10 soy sterol. Unfortunately I don’t have access to the peg-10 soy sterol. 

    Also: 
    I see ceteareth-25, Ceteareth-20, and Polysorbate 80 used by Paul Mitchell in a parallel product. 

  • chemicalmatt

    Member
    April 7, 2021 at 7:21 pm

    Sometimes imitation is not a sincere form of flattery is the lesson here. Always question authority is the other. I have no answers but questions: Why the citric acid? Why so much PVP & PVP/VA? Why the concentrations calculated into second decimal place? Why 15 parts emulsifier blend to 24 parts oil phase? Why so much fragrance? I’d start over with the idea “less is more”.

  • David

    Member
    April 7, 2021 at 7:29 pm

    use carbopol

  • prow18

    Member
    April 7, 2021 at 8:41 pm

    @chemicalmatt

    There is nothing new under the sun, there is always something you can learn from what other people have done. 

    Citric Acid balances the PH to match for hair. 

    PVP/va is 50% water

    When measuring in grams, it converts to decimals in % on excel. 

    What is your recommended emulsifier to oil ratio? 

    These fragrances are very light, took more than normal to get the fragrance to come out. 

  • prow18

    Member
    April 14, 2021 at 12:16 am

    Is HLB something to look at in this type of emulsion? 

  • Abdullah

    Member
    April 15, 2021 at 4:20 am

    Yes 
    HLB was made for such emulsifiers

  • prow18

    Member
    April 22, 2021 at 11:40 am

    @Abdullah I tried 3 variants all with the HLB balanced and none were stable. 

    Trail A
    PEG-40 hydrogenated castor oil: 3.69%
    Steareth-2: 4.91%
    Ceteareth-25: 3.26%

    Trial B:  
    PEG-40 hydrogenated castor oil: 2.75%
    Steareth-2: 4.62%
    Ceteareth-25: 3.77%

    Trial C: 
    PEG-40 hydrogenated castor oil: 2.72%
    Steareth-2: 3.97%
    Ceteareth-25: 2.99%
    PEG-100 & Glyceryl Stearate: 1.12%

    Anyone have any advice for stabilizing? 

    Emulsifiers on hand: 
    Steareth-21
    Steareth-2
    Oleth-10
    Oleth-20
    PEG-150 Distearate
    Sorbitan Oleate 
    Sorbitan Stearate 
    Ceteareth-25
    Ceteareth-20
    PEG-100 & Glyceryl Stearate 
    Polysorbate-20 
    Polysorbate-80
    PEG-7 glyceryl cocoate
    PEG-40 hydrogenated castor oil 

  • Abdullah

    Member
    April 22, 2021 at 3:17 pm

    I don’t know how how are calculating the HLB for 4 emulsifiers in a system.

    Use Steareth-21 and Steareth-2 as emulsifiers, calculate the HLB, total %2-4 emulsifier. 
    Use Cetyl Alcohol and Stearyl Alcohol as oil phase stabilizer and %0.3 xanthan gum as oil phase stabilizer. 

  • prow18

    Member
    June 3, 2021 at 3:00 pm

    After much rework, I have been able to get about 90% of the way there. The emulsion is stable in smaller batches, but when I scale up the batch sixeit has a yellow swirl that separates. I have been using a 4 blade propellor overhead mixer, and even used an immersion blender simultaneously to ensure it was mixed, but it still separates.. 

    Any feedback on why smaller batches look good but larger ones separate like this? 

  • Abdullah

    Member
    June 4, 2021 at 11:29 am

    Use homogenizer or use immersion blender for long time until everything is emulsified

    Make sure the temperature is above the melting point of evey ingredient
  • prow18

    Member
    June 4, 2021 at 3:51 pm

    @Abdullah

    What is a “long time”? 

  • Abdullah

    Member
    June 5, 2021 at 12:54 am

    I mean mix it for 10 minutes or 20 minutes or longer until everything is homogenized. 

    For samples 2 minutes mixing is enough for me

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