Cream gets thin, bodymilk-like.

I've been using cetyl alcohol as a co-emulsifier and thickener for a moisturising cream, I've alread learnt from Perry just now that cetyl alcohol isn't great as a thickener and carbomer for example is better, but I get the feeling carbomer has too many interactions. I've had a better consistency before by adding an extra emulsifiers, the difference was instead of just cetyl alcohol I added 2% of an E-wax (cetearyl alcohol + polysorbate 60).

62% deionized water
0.5% allantoin
1% glycerin
4% niacinamide
10% E-Wax (Glyceryl Stearate + PEG100 Stearate)
2% cetyl alcohol
1% cyclopentasiloxane
5% shea butter (refined)
12% Avena Sativa kernel oil
0.5% alpha tocopherol
2% bisabolol
0.7% phenoxyethanol
0.3% potassium sorbate
citric acid solution -> pH <5

Phase I: water + allantoin -> 70C
Phase II: E-wax + cetyl alcohol + shea butter -> 70C
Cooling phase: adding glycerin, niacinamide
<45C: add Avena Sativa kernel oil, alpha tocopherol, bisabolol, cyclopentasiloxane, phenoxyethanol.
Adjust pH with citric acid solution <5.
Add potassium sorbate (dissolved in a bit of the total % of water)

Note: I add some things after emulsion because I've had failures when I add them before emulsion or they're heat/pH sensitive.
I forgot about niacinamide => niacin hydrolisis at lower pH. The final pH was about 4.4 I read in this link that I shouldn't worry for some time at least.

Emulsion was liquid like bodymilk. I put it away in the fridge and after a few hours it had the right consistency, creamy thick.
I put it in an airless dispenser and put it in the fridge again.
Now, in the evening, I put some on my hand. It is liquid again?
What could've happened? I didn't add anything in between, the only thing I did was stir it a bit and put it in a container.
Next time I will add 0.5% xanthan gum I think. Does anyone have an idea what has happened/what is wrong with the formula or the way I make it? It also looks like something has recrystallized a wee bit, like a bit of niacinamide hasn't dissolved completely, which is unthinkable, I've done it numerous times before like this (adding it after emulsion in this %). It looks like there is a bit of sand in it, it is minimal and this cream is 'just' for own use only, but since I'm a perfectionist, I want to prevent this in the future!

Thanks!! Feel free to comment, I appreciate all opinions and suggestions.

Comments

  • DoreenDoreen Member
    edited June 2017
    @zwapp
    Typo, bisabolol had to be 0.2%, sorry my mistake. ;)
    (my bisabolol is natural too btw)

    Edit: I see another typo, % of water, it's late here I call it a day!
  • BelassiBelassi Member, PCF student
    You've got a solubility issue there. Obviously the emulsion is unstable. Try adding a gum / gums to stabilise it.
    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.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Why are you waiting to add the Avena Sativa Oil until cool down to 45C.  This is a major component of your oil phase ... You should be adding it with your emulsifiers and the Shea Butter.

    2% Cetyl Alcohol should be just fine to thicken your emulsion.

    As @belassi pointed out ... your issue is that you're not adding a thickener/stabilizer (ie: gum) to your water phase prior to forming the emulsion.  Add 0.3% Xanthan Gum to the heated water phase.  That should help out considerably.
    Chemist/Microbiologist formulating in the Organic & Naturals & Clean Beauty arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program/Clean At Sephora/Credo Clean guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • DoreenDoreen Member
    @Belassi, @MarkBroussard
    My idea aswell, next time I'll throw in xanthan gum also before emulsification, maybe 0.5% is too much indeed, I'll try 0.3% like you said.

    And the oat kernel oil... I was worried about that too, but since this oil can't stand heating, I thought I'll try adding it afterwards, that could be a good solution if this oil wasn't such a major part of the oil phase, like you pointed out Mark.

    About adding gums in the heated water phase: do I have to disperse the xanthan before I add it to the heated water? Or is pre hydration not needed at temperatures like 70C?
  • Disperse Xanthan gum in Glycerin first at room temperature until completely dissolved. Then add this mixture into your water phase before heating.

    I am also puzzled by the high percentage of Avena sativa oil. Adding 12% post emulsification might be a concern. This high percentage can be emulsified more efficiently if it is added into the oil phase. If you want to get away with adding it post emulsification due to its heat sensitivity, try lowering it to 1-2%.
  • johnbjohnb Member, Professional Chemist
    I also noted the high oat oil content. Not a material I would want much of in my formulations (not very stable and quite costly).

    You might also be better including a more useful amount of emulsifier. Note glyceryl stearate is not an emulsifier so you have only about 1% of PEG100 stearate present - which is a not very efficient emulsifier when use alone.
  • DoreenDoreen Member
    @johnb,
    I thought the whole combination of Glyceryl Stearate + PEG100 stearate would be a 'self-emulsifying' one. And the addition of 2% cetyl alcohol would make it a stronger one, also for the high amount of B3 and a bit thickening.
    What emulsifiers do you suggest, preferably pH stable?

    I know 12% oil is a lot and I would like the avena sativa kernel extract instead...
    It is quite costly indeed. There is only one company here that sells oat kernel oil, it's not very common, unlike wheat germ oil for example.

    @crisbaysauli,
    Thanks, I will prehydrate it with glycerin before adding to the water phase.
    Do you also have suggestions for better emulsifiers?
  • johnbjohnb Member, Professional Chemist
    The combination you are using may be OK for products with little else in them but you have quite a lot of other lipid materials in there.

    Why not try with a non-oily oat extract in place of the oil and include an emulsifier with not as high a PEG content - thinking from the "top of my head" a low HLB, low alkyl chain length material like laureth 7 or perhaps a longer alkyl chain in oleth 9 or 10. These are all pH stable (moreso than PEG100 stearate but that isn't of concern here).
  • DoreenDoreen Member
    edited June 2017
    @johnb
    Why not try with a non-oily oat extract in place of the oil 
    Like I said ^ I am desperately looking for the oat kernel extract!! People here (in this country) seem to prefer fairydust ingredients, like colloidal gold.  :/

    Thanks for the suggestions. The emulsifiers I can choose here are quite limited, so I'll go with your advice not to use too many lipid materials first. I sure will keep the types you mentioned in mind (and written on a note ;) ) as I'm keeping an eye on new suppliers, new goods in their assortment.
  • johnbjohnb Member, Professional Chemist
    I'm afraid I would class oat kernel extract (and oil) as fairy dust but that's perhaps my geriatric cynicism.

    For reference, whereabouts are you located (so we can get a better idea about what might, or might not, be available in your location).
  • DoreenDoreen Member
    @johnb
    I'm afraid I would class oat kernel extract (and oil) as fairy dust but that's perhaps my geriatric cynicism.
    Nothing wrong with your cynicism, which I think also stems from your long time experience in this field. All the reason I value your suggestions and opinions even more, since I am a total rookie!
    I do believe oat has good traits, in the proper concentration though, maybe also because I've had good experience with oatmeal on skin during eczemic outbreaks.

    I'm from The Netherlands/Holland.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Doreen81

    Why don't you consider using Oat Kernel Flour ... inexpensive and it should be readily available as opposed to Oat Kernel Oil.

    Since you have limited options ... what Emulsifiers do you have access to and then it would be easier to give you some guidance from a list that we know you can purchase.

    If your clients like Colloidal Gold ... fine, put it in there.  There's a saying in business "Feed the dogs the dog food they want to eat"
    Chemist/Microbiologist formulating in the Organic & Naturals & Clean Beauty arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program/Clean At Sephora/Credo Clean guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • DoreenDoreen Member
    @MarkBroussard
    I would love to use oatmeal, but I was afraid it's too sensitive for microbial contamination. And I thought, since it's mostly inert material, you would need a lot. And in large quantities I expect the cream to be doug-like.
    I'd like to hear your expert opinion on this!

    A list with available emulsifiers will follow, I'm off to work now.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Doreen81

    Oak Kernel Flour or Colloidal Oatmeal ... it's a cosmetic ingredient ... use it at 2% and everything will be just fine.
    Chemist/Microbiologist formulating in the Organic & Naturals & Clean Beauty arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program/Clean At Sephora/Credo Clean guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • johnbjohnb Member, Professional Chemist
    I agree with Mark's suggestion. Oat flour/colloidal oat meal has proven properties and is a nice ingredient to use - can help stabilise emulsions!
  • BobzchemistBobzchemist Member, PCF student
    I would very strongly suggest using one of the Pemulens as an emulsion stabilizer. It won't take much.

    Also, I agree with using colloidal oatmeal (the colloidal part is important, it's easier to suspend) instead of oat oil. Your skin feel will improve dramatically.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • DoreenDoreen Member
    @johnb@MarkBroussard ;
    So I really don't need to worry about it being extra sensitive for microbial growth? The combination in the concentration you mentioned earlier, with DHA, phenoxy or BA and K sorbate, good enough if I add 2.5% oatmeal? (Grahams eczemacream has 2.5% colloidal oatmeal:
    Collodial Oatmeal, Water (Aqua), Theobroma Oil (Cocoa Butter), Olea Europaea Fruit Oil (Olive Oil), Butyrospermum Parkii Seed Oil (Shea Butter), Simmondsia Chinensis Seed Oil ( Jojoba Oil), D-Alpha Tocopheryl Acetate (Vitamin E), Vanilla Planifolia Extract, Allantoin, Sodium Benzoate, Potassium Sorbate, Cetyl Alcohol, Caprylic/Capric Triglyceride, Cetearyl Glucoside, Cetostearyl Alcohol, Bisabolol, Sclerotium Gum.
    The LOI just can't be in the right order, I copied it from their site. It's a different order than on the package I once bought. Afraid of online emulators much? That's the only reason I can think of.
      
    I read a few articles on avenanthramides as being the components with the most benefits. If I am not mistaken, the avenanthramides are (partially?) lipophilic, I had hoped the oat kernel oil, which is pricey, but available, would be comparable to the extract.

    @Bobzchemist ;
    I can't get Pemulens here. I also had to google it, I read these are 'predominantly high molecular weight poly acrylic acid polymers'. Comparible to carbomer then? The reason I don't have carbomer 'in stock' is because of its instability in acidic environments, which I tend to a lot with most of my stuff (pH <5).

    Colloidal oat same story (inavailability), I'll have to use oatmeal. I can imagine the colloidal being easier to suspend, but I don't have suspending issues with oatmeal, I only notice the difference in colour in the end product.
  • You should be able to get one of theSimugels from Seppic and if so you can use to both emulsify and stabilize your emulsion.So much for your main problem.Colloidall oatmeal is a category one skin protectant so why not use it.This is not difficult so don't make it so.
  • BelassiBelassi Member, PCF student
    Colloidal oatmeal: just pulverize it in the coffee grinder and then use the finest seive you have, then pass it through again. However I go one step further, I hydrolyse it by adding a small amount of NaOH, then later I neutralise it and I have hydrolysed oatmeal which won't sink out of solution.
    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.
  • The hydrolysis made it water soluble:we can buy it here as hydrolyzed oat protein.Works well in soap bars also as it provides a consumer perceptible lather boost and skin feel!
  • DoreenDoreen Member
    edited June 2017
    @DRBOB@VERDIENT.BIZ @Belassi
    I found out that one of the intermediate suppliers here gets a lot of her stuff from Brambleberry. They have hydrolized oats in their assortment. I will ask her if she can get it in hers. It's unbelievable she hasn't yet, as being the 'most complete soapstore of Europe'. This company is located a few miles away from where I live.

    Belassi, thanks, I'll give the diy collodial and alkaline hydrolysis a try as soon as I've purchased NaOH, I need it for other purposes aswell.
    At what pH do you stop adding the NaOH solution and neutralize it? Could I neutralize it with citric acid?
  • johnbjohnb Member, Professional Chemist
    Could I neutralize it with citric acid?

    Lactic acid may be better - you will then have an additional moisturiser/skin conditioner in your product.


  • BelassiBelassi Member, PCF student
    It's super easy, believe me. Only a very small amount of NaOH is necessary. I don't have my lab results to hand, but as I remember, I used about 5g NaOH for every 100g of powdered oatmeal and left it about 30 min with slow stirring. It will change colour. Then simply neutralise with citric (or lactic if you can get it) for pH = 7 and you will find the colour changes back to the normal oat colour. Don't forget any excess will need preserving!
    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.
  • Doreen, swiftcraftymonkey has written posts on Glyceryl Stearate + PEG100 stearate (known as lotionpro), it's a lovely strong emulsifier: http://swiftcraftymonkey.blogspot.co.uk/2014/01/emulsifiers-lotionpro-165-in-lotion.html

    It works so well for me.  
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