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Tagged: cold-process, emulsifier, emulsion, o-w, stability
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Cold process O/w thin lotion stability issue
Posted by Abdullah on November 24, 2020 at 11:34 amI 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= 6.97Water phase
Water to %100Emulsifiers
Polyglyceryl-4 Laurate %53.38 Hlb 10
Glyceryl oleate %46.62 Hlb 3.5
This mixture gives Hlb 6.97I 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, 11 months ago 7 Members · 26 Replies -
26 Replies
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@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).
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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?
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@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.
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@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.
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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)
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@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 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.
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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?
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Add carbomer with the water(increase the ph to get thickened with NAOH OR TEA) than add the other ingredients
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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%
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