how to prevent cream from emulsifying on the skin

Tagged: formulation

Formulating

how to prevent cream from emulsifying on the skin

Posted by billichemist on October 20, 2016 at 4:12 am

Hi there,

me again.

My cream/lotions turn white when i rub it onto my skin. if i am not wrong, this is because the cream is emulsifying/foaming on my skin yes?

How do i prevent this? My emulsifier to oil ratio is around 28%… does the type of emulsifier increase the foaming of creams as well?

Chemist77 replied 8 years, 1 month ago 7 Members · 13 Replies
- formulation
13 Replies

billichemist

Member
October 20, 2016 at 4:24 am

i also have 0.2% xanthan gum in the emulsion. will that affect it?
chemicalmatt

Member
October 20, 2016 at 3:36 pm

Add a fatty alcohol to your emulsion - cetyl or stearyl - and that should be the end of that; unless of course you have a foaming surfactant in there you aren’t divulging. e.g. a betaine or a glucoside. If so, then rename it a “foaming lotion”. Marketing can solve these problems when chemistry cannot.
billichemist

Member
October 23, 2016 at 9:19 pm

@chemicalmatt
Thank you for that! it currently already has 1.5% cetyl alcohol in it!!!

here is the emulsion system..

olivem1000-1%
Cetyl alcohol - 1.5%
Stearic Acid -0.8%
Glyceryl Monostearate -0.8%
coconut oil - 0.5%
macadamia oil - 3.5%

% of emulsifiers to oil is 28%. should i increase the cetyl alcohoL?
ozgirl

Member
October 23, 2016 at 10:01 pm

I think you are talking about what is often referred to as the “soaping effect”.

This old thread may be of interest.
https://chemistscorner.com/cosmeticsciencetalk/discussion/90/soaping-whitening-when-cream-is-rubbed-into-skin
johnb

Member
October 24, 2016 at 7:01 am

Is the non-declared part merely water and preservatives?

A quick glance at the delared formula suggests too high a proportion of emulsifier.
billichemist

Member
October 24, 2016 at 9:30 pm

@johnb yeh water, preservative and some extracts and i have a littl ebitof xanthan gum in it,

@ozgirl os it says less fatty alcohols!! i am so confused
Chemist77

Member
October 25, 2016 at 4:41 am

Is it not possible for you to add little dimethicone (350cs @0.5%) and see how it performs in the existing recipe that you have mentioned above.
billichemist

Member
October 26, 2016 at 3:58 am

@Chemist77
i will try it just to see what effect it has but i cant be in the final formula because its mean to be certified organic.

do i put it in the hot phase or can i post add/ add in the cold phase?
Chemist77

Member
October 26, 2016 at 1:22 pm

Generally i add it immediately after emulsification as mixing with regular oil phase doesn’t produce uniform oil phase. Though you can add it to your oil phase, generally.
johnb

Member
October 26, 2016 at 2:21 pm

Far too much emulsifier.
Christopher

Member
October 27, 2016 at 12:12 am

I can confirm that dimethicone will reduce the soaping effect. I’ve made
a similar formula with and without 2 % dimethicone and latter one did
not rub in white.

@chemicalmatt: Really? I’ve had the exact opposite experience. If I don’t include cetyl alcohol or stearic acid there’s no soaping effect.
Bati

Member
October 28, 2016 at 5:26 pm

I have found Stearic Acid to be particularly troublesome with regard to soaping (whitening on rub in) in cream/emulsion formulas. I would replace it with Cetyl Alcohol and see where that gets you.

Additionally, what is your pH. Stearic acid turn into “soap” at high pH.

I’m not sure what you mean with regard to your emulsifier:oil ratio. Your emulsifier levels look adequate for the amount of oil you have. You could even consider reducing them slightly. I have seen soaping with GMS also, but not to the extent of stearic acid. Perhaps try replacing that also.
Chemist77

Member
October 29, 2016 at 4:04 am

GMS esp the SE grade has some soap content and thats why mild soaping can be observed, again just replacing Stearic acid with cetyl won’t help alone given the list of emulsifiers mentioned above.