Cold process W/O emulsion viscosity drop

DoreenDoreen Member
edited April 2018 in Formulating
Today I've experimented and made a high internal phase emulsion with Easynov (cold process). The emulsion started thick creamy, but when I added a few ingredients after emulsification, viscosity dropped and it turned more liquid, like body lotion. I would like to know the reason, because I prefer it thicker, creamier.

My formula:

A )
ad 100 Water distilled & deionized
3.0%    Glycerin
0.2%    Dermofeel PA-3 (Sodium Phytate, Water, Alcohol)
1.5%    Niacinamide
2.0%    Fig extract (Water, glycerin, Ficus Carica Fruit Extract, Potassium Sorbate, Sodium                   Benzoate, Citric Acid)
1.0%    Cucumber extract (Propylene Glycol, Cucumis Sativus Fruit Extract)
0.5%    Dipotassium glycyrrhizinate
2.0%    Sepimax Zen (Polyacrylate crosspolymer-6)

B )
3.0%    Easynov (Octyldodecanol, Octyldodecyl Xyloside, PEG-30 Dipolyhydroxystearate)
5.0%    Isoamyl Laurate
2.0%    Caprylic/Capric Triglycerides
0.1%    Tocopherol

C )
1.0%   Cyclopentasiloxane
1.0%   Phenonip
0.2%   Parfum

- Dissolve and mix A until gel has formed
- Stir B until homogenous
- Add A to B low shear
- Add C ingredients individually to A+B

I don't have a proper mixer, like an Ultra Turrax, so for low shear I use a simple kitchen mixer with beater attachment. For high shear a stick blender.
I mixed Sepimax Zen in phase A with the stick blender and I got too much air trapped and a bit foam on top. (Batch size (too small): 150 grams in 250 ml beaker)
The gel was thick, very short flow.
When I added the gel to the oil phase, I used high shear (stick blender) instead of the recommended low shear (in the video on UL Prospector).

It started emulsifying beautifully, to be honest I didn't expect it because the gel was so crappy. A nice, thick creamy emulsion with no air trapped! (The trapped air and foam seem to disappear when emulsificating?)
I added the cyclo, Phenonip and the fragrance (just stirring with a glass stirrer).
Maybe even just before adding these or while I don't know precisely, but the emulsion started to become more liquid, less viscous.

Was it the high shear? Or didn't I mix long enough? (I mixed very very shortly, because of the extreme small batch size).

(Btw, the sensorials are good. It doesn't feel greasy at all, like what you expect from W/O.)

Comments

  • ozgirlozgirl Member, PCF student
    Some fragrances and some preservatives are known to thin emulsions. Try a knock out experiment to see if this problem is caused by one of your raw materials.
  • DoreenDoreen Member
    @ozgirl
    Ok, thanks!! :-) I will do that!
  • DoreenDoreen Member
    edited May 2018
    @ozgirl
    Would you recommend to put phases B and C together? (just one oil phase)
  • Chemist77Chemist77 Member, PCF student
    @Doreen think you should try that since I have done something similar in the past and it came out pretty consistent. 
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