Home Cosmetic Science Talk Formulating Cold process O/w thin lotion stability issue

  • Cold process O/w thin lotion stability issue

    Posted by Abdullah on November 24, 2020 at 11:34 am

    I am working in this basic thin o/w lotion, the problem is after a few hours it separate in two parts. a cream like in top and water like in bottom. 
    I use Hlb system. 
    It is cold process.

    Here is ingredients

    Oil phase
    Olive oil %9.3   Hlb 7
    Glyceryl caprylate %0.7   Hlb 6.6
    Hlb of oil phase= 6.97

    Water phase 
    Water  to %100 

    Emulsifiers
    Polyglyceryl-4 Laurate %53.38  Hlb 10
    Glyceryl oleate %46.62  Hlb 3.5
    This mixture gives Hlb 6.97 

    I used %4 and %5 emulsifier mix but separated.

    I mix Polyglyceryl-4 Laurate in water and glyceryl oleate in oil and then add oil to water while mixing with stick blender.

    What is your suggestions to stabilize it. 

    Thanks in advance

    Andraous replied 3 years, 3 months ago 7 Members · 26 Replies
  • 26 Replies
  • Abdullah

    Member
    November 24, 2020 at 12:20 pm

    This is how it looks

  • ketchito

    Member
    November 24, 2020 at 5:42 pm

    @Abdullah Since you’re making an O/W emulsion, you’d need a higher amount of a high HLB emulsifier. Also, I’d choose a high HLB emulsifier with a higher HLB (closer to 14-15).

  • Abdullah

    Member
    November 25, 2020 at 1:49 am

    @ketchito the Hlb of oil mix is 6.97 
    If i increase the amount of high HLB emulsifier it would be more than 6.97. 
    Is that ok? 

  • singhc10

    Member
    November 25, 2020 at 12:06 pm

    @abdullah, what is going to be the packaging of this product, is it going in a  spray bottle?

  • ketchito

    Member
    November 25, 2020 at 4:40 pm

    @Abdullah The HLB rule is more like a reference, and actually doesn’t work for many emulsifiers. That being said, if your difference on HLB between your emulsifiers is high, that can give you better stability (just consider one of the most used emulsifying systems: Glyceryl Stearate (and) PEG-100 Stearate). 

  • Abdullah

    Member
    November 26, 2020 at 7:42 am

    @singhc10 it is low viscosity lotion pump

  • Abdullah

    Member
    November 26, 2020 at 7:45 am

    @ketchito i am locking for a cold processable emulsifier.

  • Pattsi

    Member
    November 26, 2020 at 8:09 am

    try using commercial blend like Viscolam® AT 100/P

  • singhc10

    Member
    November 26, 2020 at 12:26 pm

    @Abdullah 

    • Problem with your formulation is stabilization of oil particles, both of your emulsifiers are nonionic. Try adding another Cationic( Distearyldimonium Chloride) or anionic(sodium stearoyl Glutamate) emulsifier for charge stabilization
  • Bill_Toge

    Member
    November 26, 2020 at 7:24 pm
    the fundamental problem is that you’ve got nothing in the water phase to physically prevent the oil phase from coalescing and separating; what you need is something that will make the product effectively non-fluid at rest (so the emulsion droplets can’t physically move)
    there are several possible ways this can be done - how viscous do you want your finished product to be?
  • Abdullah

    Member
    November 27, 2020 at 3:45 am

    @Bill_Toge i think that was the problem. I made another samples with %0.1 and %0.2 xanthan gum after i saw your comment. The one with %0.2 xanthan gum is stable yet.

    As xanthan gum is anionic, here is another problem. I want to add Ethyl Lauroyl Arginate HCl which is cationic surfactant and incompatible with anionic xanthan gum. So what non-ionic stabilizer should i use? 
    Both natural and synthetic options. Good skin feel is preferred.

    I want to make two versions. One low viscosity less than 3000 cps and one lotion. More than 20000 cps. 

  • ketchito

    Member
    November 27, 2020 at 1:52 pm

    @Abdullah Xanthan gum will only increase the viscosity in the aqueous phase, so you still need a good emulsifying system. If your process is cold and if you’re using non polymeric emulsifiers, I think that might be a problem, since you need thermal energy for conventional emulsions to occur. If your process is cold, then you better use a cold processable polymeric emulsifier.

  • Bill_Toge

    Member
    November 28, 2020 at 3:34 am
    a good way to make a water-thin emulsion is to use 0.1% low-acyl gellan gum in the water phase, cross-linked with 0.1% calcium chloride (or an equivalent weight of another calcium salt)
    if you want a thicker product, add cetyl/stearyl/cetearyl alcohol and/or stearic acid to the oil phase; fatty alcohols will increase zero-shear viscosity (makes it feel thicker), and stearic acid increases the high-shear viscosity (makes it feel richer)
  • Abdullah

    Member
    November 30, 2020 at 3:44 am

    @Bill_Toge 
    I use Ethyl Lauroyl Arginate HCl which is cationic and gellan gum is anionic. They would not be compatible as Ethyl Lauroyl Arginate HCl is not compatible with xanthan gum too which is anionic.
    Is there any non-ionic or cationic oil stabilizer option?

  • Abdullah

    Member
    November 30, 2020 at 3:51 am

    @ketchito what is the difference between polymeric and non polymeric emulsifier? 
    Can you suggest some polymeric emulsifiers? 

  • ketchito

    Member
    November 30, 2020 at 1:49 pm

    @Abdullah Polymeric emulsifiers are polymers that sit in the interphase of the emulsion, not only physically stabilizing the emulsion, but also interacting with the oil phase. They are independent of the HLB requirements of your system. I used a couple of them in the part: Sepigel 305 and Novemer EC-1, but there are many more.

  • Abdullah

    Member
    December 26, 2020 at 4:08 am

    Bill_Toge said:

    the fundamental problem is that you’ve got nothing in the water phase to physically prevent the oil phase from coalescing and separating; what you need is something that will make the product effectively non-fluid at rest (so the emulsion droplets can’t physically move)
    there are several possible ways this can be done - how viscous do you want your finished product to be?

    Is it the viscosity of thickner in water phase that prevent the oil phase from coalescing and separating, or the yield value? 

  • chemicallydivinelab

    Member
    December 31, 2020 at 6:22 pm

    you could try cationic guar gum 

  • chemicallydivinelab

    Member
    December 31, 2020 at 6:23 pm

    however it might be hard to get to thicken.

  • Andraous

    Member
    January 1, 2021 at 3:25 pm

    Add carbomer with the water(increase the ph to get thickened with NAOH OR TEA) than add the other ingredients

  • Andraous

    Member
    January 1, 2021 at 3:26 pm

    You can also add polysorbate 20

  • Abdullah

    Member
    January 2, 2021 at 2:09 pm

    @chemicallydivinelab thanks 
    I did make a sample with cationic guar too. It was not stable. 

  • Abdullah

    Member
    January 2, 2021 at 2:11 pm

    @Andraous thanks 
    I want to add sodium lactate and sodium salicylate in this formula. 
    Would carbomer be stable in it? 

  • Andraous

    Member
    January 2, 2021 at 8:14 pm

    Abdullah said:

    @Andraous thanks 
    I want to add sodium lactate and sodium salicylate in this formula. 
    Would carbomer be stable in it? 

    Your welcome 
    You have to try but i think it’s feasible 
    But try to add first water + carbomer for 30 min then add 2-amino-2-methyl-1-propanol 01% to get thicken.
    Then add the other ingredients 
    It should be stable 
    In case the viscosity decrease after adding the other ingredients you can re-add 2-amino-2-methyl-1-propanol  0.1%

  • Abdullah

    Member
    January 3, 2021 at 11:14 am

    @Andraous is 2-amino-2-methyl-1-propanol just for adjusting pH or it has other function too?

    Which carbomer do you prefer? 

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