Hi, everyone. I made an emulsion using water, mineral oil, Stearic acid, cetearyl alcohol, glycerine, sodium lactate, butylene glycol, propylene glycol, Triethanolamine, sorbitol, dimethicone, isopropyl myristate, petroleum jelly, Carbomer and Euxyl K712. When I used the mixer after heating the phases it curdled…water at the bottom. I continued to mix it manually using a spatula and somehow with that, as it cooled, it came together. The curdling/ separation has never happened for me before. What could have been the cause?
My eyes also seem to be sensitive to it…when I sniff it I get the same sensation as I do from menthol. What could the reason be?
The ingredients I haven’t used in an emulsion before here are the sodium lactate (2.5%), butylene glycol (1%)and sorbitol (1%).
Any similar experiences? Tips?
Also, what can I do to make my emulsion flow easily out of the bottle. It is meant to be a lotion but is too thick. My water % is 79.
Comments
you would need to provide full formula with %, so we can review the inputs. Imagine making a special soup where you know only the ingredient, but no the amounts and method.
water 78.45%
mineral oil - 4%
Stearic acid - 2%
cetearyl alcohol - 1%
glycerine - 2.5%
sodium lactate - 2.5%
butylene glycol - 1%
propylene glycol - 0.8%
Triethanolamine - 0.5%
dimethicone - 1%
Potassium sorbate - 0.1%
sodium benzoate - 0.2%
The addition of the sodium lactate was to create a feel that is better than just glycerine. Would keeping the Carbomer and dropping the sodium lactate and using 5% glycerine make for a more stable emulsion?
I normally make the lotion without the sodium lactate or sorbitol or butylene glycol and it turns out okay. I found that this particular formulation dried faster and seemed less greasy and didn’t make users sweat, even in humid areas.
Any ideas on which of these 3 ingredients could be slightly sensitizing?
What would you suggest for a more robust emulsification system?
Which viscosity dimethicone?
As Graillotion said, use a proper emulsifier and remove carbomer if you want to use sodium lactate. Use xanthan gum instead.
Use a proper preservative
Reduce the fragrance to 0.1%
Maybe reduce EDTA too a bit
What emulsifier would you switch out the GMS and CSA for?
water 78.45%
Carbomer - 0.05%
Triethanolamine - 0.5%
glycerine - 2.5%
sorbitol - 1%
sodium lactate - 2.5%
butylene glycol - 1%
propylene glycol - 0.8%
DiSodium EDTA - 0.25%
mineral oil - 4%
dimethicone - 1%
IPM - 1%
isopropyl myristate - 1%
Cera microcrystallina- 0.5%
cetearyl alcohol - 1%
Glyceryl monostearate - 2%
sodium benzoate - 0.2%
You have 5 humectants, why? Is it for marketing? If so, put them at 0.1% and choose 1-2 to be the main ones. Glycerin and Sodium Lactate for example.
I believe you have way too much Triethanolamine to neutralize the Carbomer.
The ratio is 1.0-1.5 : 1.0 - TEA : Carbomer. Keep in mind you cannot adjust the final pH anymore. Also, as mentioned, the sodium lactate is most likely making the carbomer useless.
Better pick some other rheology modifier to make it easier for you. Xanthan Gum is perfect choice. Natural, easy to slurry with all those humectants, bang bang boom.
Ok, oil phase.
IPM should stand for isopropyl myristate. Is it doubled then?
Stearic acid is an anionic emulsifier. Has a strong charge (also affected by Sodium lactate as it's an electrolyte), so you might want to re-think that and use higher portion of non-ionic high HLB waxy BLEND emulsifier.
Glyceryl monostearate is low HLB emulsifier - preferably suits W/O emulsion. Or it can help with rubbing time and viscosity, however as you are using Dimethicone, that won't be your issue. You can get rid of it.
So looking over the formula, you have one anionic emulsifier, one W/O emulsifier and a bit of thickener/co-emulsifier. That is why people didn't like it.
The W/O emulsifier would most likely destabilize you formula.
The 0.8% fragrance is making me dizzy
!!!!! Also, those preservatives can be also irritating. And they work ONLY in lower pH. According to your TEA input, I'm pretty sure you have not reached this and bang, you have contamination/microbial growth!!! . Use some Euxyl PE 9010 or similar. !!!!!
Ok, I think I'm done
I will consider the xanthan gum…would using it as a substitute get rid of the necessity of using the TEA?
On fragrance…my users were unhappy with my initial 0.5% so I increased the amount. Fancy that.
It is all about the thickeners.
I can make something that looks like a solid...with 99.2% water. Hehehe...just experiment with polymeric emulsifiers.
It is one of the least expensive and mildest preservatives. Is is milder than benzyl alcohol, sodium benzoate and potassium sorbate.
With xanthan gum you don't need tea.
Is this product for sale or your own use?
You can use Paraben. It is non irritant or the year 2019 preservative. I think most people don't care about it as big companies like Cerave is using it.
Thickeners will always be formula specific....so the correct answer will be the one I always get from my mentor....'DEPENDS'...
Aloha.