How to Add Sepimax Zen to a Lotion
First off, a huge thank you to all who provide so much knowledge here. I am not a cosmetic chemist, which will be very obvious momentarily, but a home-crafter and this forum has been a valuable source of information over the past year. I am working on stabilizing a body lotion that uses LotionPro 165 (glyceryl stearate and PEG 100 stearate) with Sepimax Zen (polyacrylate crosspolymer-6). I read a post that said to add it to the oil phase and another that said to add it to the water phase while overhead mixing. To put it simply, I’ll state my questions upfront and then detail what I actually did:
- What is the optimal phase/temp to add the SepimaxZen, and the best method for incorporating into a lotion?
- In my first try, I added it to the water phase. Would that pose any long-term issues to my formula? (More details on the process below)
My reason for adding the polymer is due to, as you guessed, stability issues with the lotion that did not have any polymer around the 9-month mark. It started to thin out considerably, which is what I surmise as separation happening. The heat wave here in the West didn’t help either. So I researched that I needed a rheology modifier like xanthan gum or a polymer to stabilize it. I chose Sepimax Zen for its wonderful sensory profile and I already had quite a lot of it from making hand sanitizer.
My formula and process is below:
Note: I do not have an overhead mixer but have rigged my immersion blender with a rheostat for variable speed and attached it to stand for overhead mixing. It can usually go 10 minutes on the lowest setting without overheating.
Ingredient Phase G % Distilled Water A 1,988.6 53.6% Rose Hydrosol A 445.2 12.0% Propanediol 1,3 A 74.2 2.0% dl-Panthenol A 74.2 2.0% Hydrolyzed Rice Protein A 74.2 2.0% Disodium EDTA A 7.4 0.2% Sepimax Zen A 7.4 0.2% Shea Butter B 207.8 5.6% Jojoba Oil B 207.8 5.6% Macadamia Oil B 163.2 4.4% Avocado Oil B 163.2 4.4% Cetyl Alcohol B 74.2 2.0% LotionPro 165 B 148.4 4.0% Vitamin E C 3.7 0.1% AromaFix C 11.1 0.3% Lavender 40/42 EO C 40.8 1.1% Lavender 40/42 EO C 18.6 0.5% Total 3,710.0 100%
Sepimax Zen = polyacrylate crosspolymer-6
LotionPro 165 = glyceryl stearate and PEG 100 stearate
AromaFix = PPG-20 Methyl Glucose Ether (helps the fragrance/eo stay longer)
- Turn on water bath and set temp to 84˚C.
- Weigh distilled water and place into glass beaker.
- Weigh Sepimax Zen and sprinkle on top of Waters A and let hydrate for 10 minutes.
- Mix Waters A on low with stick blender for 3 minutes.
- While continuing to mix on low, weigh and combine each remaining ingredient for phase A one at a time. Record all weights, including the glass beaker. (Total mix time appx 8 min)
- Weigh and combine all ingredients for Oils B. Record all weights, including the glass beaker.
- Place Waters A in water bath and heat to 80˚C. Lower water bath temp to 80˚C.
- Cover Waters A and hold for 20 minutes to kill bacteria and mold spores.
- While Waters A are holding, place Oils B in water bath and heat to 80˚C.
- Weigh Waters A and top off with 80˚C distilled water.
- With the stick blender immersed into the Oils B container, pour Waters A in and blend with stick blender on high for 3 minutes until it has emulsified to an opaque, uniform consistency.
- Place in a cold-water bath and mix on low until the lotion reaches 48˚C, ~5 minutes.
- Remove from cold water bath and mix in Phase C until fully incorporated, ~2 minutes.
- Place the beaker back in the cold-water bath and mix on low until the lotion reaches 30˚C, ~15 minutes.
- Remove from cold water bath and allow lotion to reach room temperature before packaging.
My initial reaction to the revised formula with the polymer was that it felt wonderful on my skin, ultra-hydrating yet light and fast-absorbing. The most noticeable difference is in the way it “breaks”. It passed my in-house 5-cycle freeze-thaw stability test as well as three weeks in the incubator at 45˚C.
But now I’m wondering if because I added it to the water phase and not the oil phase, that I might have longer-term stability issues. Something that might not creep up until 6-months from now. Is there anything else I’m not considering that I should?
Any advice and feedback would be greatly appreciated! <3
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