Olivem 900 Failed Emulsions

Hi,
I would really appreciate if someone could help me with my problem with these failed experiments with Olivem 900 (Sorbitan Olivate). I made 9 experiments and none has properly emulsified. 
Experiment 1-4 Formula (2 with 0.5% salt and less 0.5% Water) 50g each:

Water 49.68%
Glycerin 3%
Citric Acid (as chelating agent) 0.02%
Preservative Eco 0.8%

Olivem 900 6%
Cetyl Alcohol 2%
Cocoa Butter 7%
Coconut Oils 30%

Orange EO 1%
Vitamin E 0.5%

Mix water + glycerin + citric acid, adjust pH to around 5, add preservative eco, adjust pH to about 5.3. Heat both phases to 75°C. Drizzle water phase into oil phase in a stream and emulsified with a Bamix mixer. Emulsion didn't come together. Didn't get to cool down phase. I observed that perhaps the quantity was not enough for the Bamix homogeniser to do its job. So trial 5 and 6, I increased the quantity to 100g, the result was slightly better than 1-4, the 2 phases were emulsified but was very watery/fluid and could see traces of separation. I homogenised the emulsion for more than 1 minute with the Bamix and stir till cool down to 35°C.  Left it for an hour and the emulsion started to separate.

Experiment 7, I changed the formula and tried it at 100g:

Water 35.98%
Glycerin 3%
Citric Acid 0.02%
Salt 0.5%
Preservative Eco 1%

Olivem 8%
Cocoa Butter 10%
Coconut Oil 40%

Cool Down Phase: 1.5% (Vitamin E 0.5%, EO Cedarwood 1%)

Same method as above, emulsion was water/fluid. When it cooled down to 32°C, the emulsion thickened a little but it was still fluid, and I could traces of (water or oil) around the rim of the emulsion.
Experiment 8, I reduced water by 10% and increased coconut oil by 10%, consistency was slightly better but still quite fluid but there are no traces of water/oil around the rim.
24 hours later, both experiments 7 and 8 are still fluid. 

Experiment 9, also 100g, formula:

Water 30%
Glycerine 4%
Salt 0.5%
Preservative Eco 1%

Olivem 8%
Shea Butter 10%
Sunflower Oil 45%

Cool Down 1.5% (Vitamin E 0.5%, EO Cedarwood 1%)

For experiment 9, same method of formulation as above, except that I let the Bamix run for 2 minutes. Result is the same, watery emulsion with traces of oil/water around the rim.

Sorry for my very long post but I wanted to get as much detail down as possible to make it easier for whoever will help me. I have made various adjustments, adjusting the pH of water phase before adding preservative, increasing oil phase, increasing mixing time, removing citric acid etc but still, it doesn't work. 

I hope someone can shed some light please.Thank you!

Mary Lau

Experiment 7, 8, 9 in descending order



Comments

  • PerryPerry Administrator, Professional Chemist
    Are you familiar with the HLB system

    Basically, to make a stable emulsion you need to match the HLB of your emulsifier with the required HLB of the oils you are using.

    Olivem 900 has an HLB of 4.7

    Coconut oil requires an HLB of 8
    Shea butter requires an HLB of 8
    Sunflower oil HLB is 7

    If you want to emulsify those oils, you need an emulsifier system with an HLB of 7 or 8.  Olivem 900 will not work (unless you also include an emulsifier with an HLB of 11 or 12.

    Also, when making an emulsion you should use more than one emulsifier if you want it to be stable.
  • EVchemEVchem Member
    Likely you'll need more than one emulsifier, that's the first issue.
    I see the use level for olivem 900 is around 1-4%  for w/o, i only saw it at 12% for a totally anhydrous product.

    W/O  products are challenging. You're homogenizing so that's good (do you know what RPM?), but I'd recommend doing it again at a cooler temp when your phases are a little more solidified. Other tip would be add the water painstakingly slow, in small increments watching it fully incorporate before you  move to the next addition

    I'll be honest, I don't know how to decide if you need more salt or not (other than experimentation) but that could be another issue.
  • africanbugafricanbug Member
    edited May 21
    Hi Perry,

    Thank you for taking the time to read through my post. I don't know much about HLB system but from what I just read and your reply, please tell me if I have understood and made the HLB calculation rightly:

    Oil Phase is 60% of formulation
    10% Cocoa Butter, 16.7% of Oil Phase HLB 6 = 0.167x6 = 1.002
    50% Coconut Oil, 83.3% of Oil Phase HLB 8 = 0.833x8 = 6.664
    Total = 7.66

    So, to emulsify this mixture of oils, I will need

    Emulsifier is 7% of formulation
    4% Olivem, 57.14% of Emulsifier HLB 4.7 = 0.571x4.7 = 2.69
    3% Sucrose Stearate, 42.9% of Emulsifier HLB 11 = 0.428x11 = 4.719
    Total = 7.409

    Is that correct? Also, could you please tell me generally, does "oil phase" include emulsifiers or it is solely the oils?

    Many thanks again.

    Mary
  • PharmaPharma Member, Pharmacist
    I like Olionatura.de: Assuming you're not German speaking, here a short translation of what she says about Olivem 900:
    Olivem 900 is a w/o emulsifier supposedly good for oil phases above 50% and requires at least 75°C. Given your description of a liquid product implies a o/w emulsion which won't be stable. The required HLB values posted by @Perry are only valid for o/w emulsions, not w/o (they tend to be lower there) ;) . For o/w emulsions you might have to add more Olivem and more cetyl alcohol, not less.
    Try using more than 50% oil phase, 7-8% Olivem, cetyl alcohol is optional but might boost stability and creaminess.
    As @EVchem said, add the water phase very slowly and make sure everything is homogeneous before you add more. Keep on mixing until cold and don't cool too fast. BTW Bamix are kitchen stick blenders with an astonishing RPM for such tools (depends on the model, somewhere between 12'000 and 17'000 RPM).
  • BelassiBelassi Member
    "... astonishing RPM for such tools (depends on the model, somewhere between 12'000 and 17'000 RPM" - hell that's nothing, my Yamaha RD200 street bike could go to 14,000...

    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • PharmaPharma Member, Pharmacist
    Unlike in Mexico, using street bikes as kitchen tools is a no-no here around.
    BTW 'normal' stick blenders have something around 7'000 RPM.
  • Thank you all for your very helpful contributions. Following Perry's advise, I revised the oil phase to  

    10% Cocoa Butter
    50% Sunflower Oil
    (Total HLB 6.83)

    5% Olivem 900
    1.3% Cetyl Alcohol
    (Total HLB 6.9)

    and it is the best result I have seen so far. The emulsion looks to be stable and is thickening slowly. I can't wait to see it tomorrow and fingers crossed. Not sure if I have gotten this right so if anyone sees a folly in my formula, please do correct me. Thank you!

    ps: Thank you very much Perry!


    Pharma said:
    I like Olionatura.de: Assuming you're not German speaking, here a short translation of what she says about Olivem 900:
    Olivem 900 is a w/o emulsifier supposedly good for oil phases above 50% and requires at least 75°C. Given your description of a liquid product implies a o/w emulsion which won't be stable. The required HLB values posted by @Perry are only valid for o/w emulsions, not w/o (they tend to be lower there) ;) . For o/w emulsions you might have to add more Olivem and more cetyl alcohol, not less.
    Try using more than 50% oil phase, 7-8% Olivem, cetyl alcohol is optional but might boost stability and creaminess.
    As @EVchem said, add the water phase very slowly and make sure everything is homogeneous before you add more. Keep on mixing until cold and don't cool too fast. BTW Bamix are kitchen stick blenders with an astonishing RPM for such tools (depends on the model, somewhere between 12'000 and 17'000 RPM).
    I am actually trying to achieve a w/o emulsion.. yes, the Bamix is quite a solid homogeniser, mine is between 14,000 - 18,000rpm) 
  • I thought it's high internal phase W/O as there is salt as a stabiliser there. W/Os are extremely challenging and process sensitive. I haven't worked with Olivem 900 but in any case you need at least two emulsifiers. You need stabilisers for both oil and waterphase. You are already using salt for the waterphase, now you need to add magnesium stearate or zinc stearate or hydrogenated castor oil or anything that works as oil gellant. You need an overhead stirrer that you would set up at low shear and water is to be added with a pipette by drops. You need to wait for the temperature to drop to <50C and only then apply high shear which will increase viscosity. And don't do it for too long. Also, as it was mentioned above, your emulsifier might not be designed for making high internal phase w/o emulsions. You have to reconsider your emulsification system.
  • africanbugafricanbug Member
    edited May 22
    I thought it's high internal phase W/O as there is salt as a stabiliser there. W/Os are extremely challenging and process sensitive. I haven't worked with Olivem 900 but in any case you need at least two emulsifiers. You need stabilisers for both oil and waterphase. You are already using salt for the waterphase, now you need to add magnesium stearate or zinc stearate or hydrogenated castor oil or anything that works as oil gellant. You need an overhead stirrer that you would set up at low shear and water is to be added with a pipette by drops. You need to wait for the temperature to drop to <50C and only then apply high shear which will increase viscosity. And don't do it for too long. Also, as it was mentioned above, your emulsifier might not be designed for making high internal phase w/o emulsions. You have to reconsider your emulsification system.
    thank you ngarayeva001! unfortunately my latest experiment is starting to look unstable. I can't find any information on adding stabilisers for the oil phase, at what percentage should I add it please? will beeswax be able to act as a stabiliser? 
  • PharmaPharma Member, Pharmacist
    I thought it's high internal phase W/O as there is salt as a stabiliser there. W/Os are extremely challenging and process sensitive. I haven't worked with Olivem 900 but in any case you need at least two emulsifiers. You need stabilisers for both oil and waterphase..
    It's not a HIPE, just a w/o emulsion with an amount of oil which is said to be suitable for Olivem 900.
    Olivem 900 & cetyl alcohol would be regarded as two emulsifiers in this system. There is no inherent necessity to always use two emulsifiers. Using chemically pure single molecules tends to result in less stable emulsions and there, two or three emulsifiers are usually superior. Olivem 900 on the other hand is an olive oil derived emulsifier which therefore contains a mix of different fatty acids (mostly palmitic, oleic, and linoleic acid). This already counts as emulsifier combo.
    Cocoa butter serves as oil gelling agent.
  • @Pharma, I am not disputing what you are saying about cetyl alcohol and coconut oil as an oil gelling agent, but water in oil emulsions are utterly unpredictable, and when someone without years of experience makes them they need all help that they can get (I am referring to the second emulsifier and several stabilisers). I made so many failed w/o that I stopped counting. I am just suggesting what I know would work based on my experience.

    @africanbug, I think cetyl alcohol should be replaced with beeswax 2%. And the second w/o emulsifier might help with stability a lot.

    https://knowledge.ulprospector.com/306/pcc-ask-expert-water-oil-emulsion-unstable-can/

    I tried all polymeric emulsifiers listed in the article (except for Abil EM 180, I used Abil EM 90 is similar). If you can get PEG-30 DPHS (not only made by Croda) or Isolan GPS as your second emulsifier, it might solve your problem.

    It would also help to add magnesium stearate at 0.5-1% (melt it properly, it has a high melting point). 

    Increase NaCl to 1-1.5% and keep in mind it's early to celebrate success if it looks stable the next day. Sometimes W/O separate several weeks or months later. 
  • PharmaPharma Member, Pharmacist
    And sure you're right. Nice feeling w/o are finicky. What we do in pharmacy is quite often to gel the oil phase to the point where it gets an apparent melting point above maybe 30°C. This kind of 'solid' product remains fairly stable even if, on a theoretical level, it's not. Best example is traditional cold cream.
    Isolan GPS sound like something worth trying, gotta give that a shot one day myself.
  • africanbugafricanbug Member
    edited May 23
    @ngarayeva001, thank you so much for your very kind advice ❤️. I made a few experiments today implementing your comments, I've got 2 emulsions that look promising. Fingers crossed.

    I am in a natural skincare formulation course and therefore, ingredients have got to be natural..I have read that synthetic emulsifiers are less of a pain than natural but well..

    Thank you everyone for your kind comments :) 
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