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
10% E-Wax (Glyceryl Stearate + PEG100 Stearate)
2% cetyl alcohol
5% shea butter (refined)
12% Avena Sativa kernel oil
0.5% alpha tocopherol
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 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.