How to Add Sepimax Zen to a Lotion

Hello Everyone!

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:

  1. What is the optimal phase/temp to add the SepimaxZen, and the best method for incorporating into a lotion?
  2. 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)

PROCEDURE
  1. Turn on water bath and set temp to 84˚C. 
  2. Weigh distilled water and place into glass beaker.
  3. Weigh Sepimax Zen and sprinkle on top of Waters A and let hydrate for 10 minutes.
  4. Mix Waters A on low with stick blender for 3 minutes.
  5. 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)
  6. Weigh and combine all ingredients for Oils B. Record all weights, including the glass beaker.
  7. Place Waters A in water bath and heat to 80˚C. Lower water bath temp to 80˚C.
  8. Cover Waters A and hold for 20 minutes to kill bacteria and mold spores.
  9. While Waters A are holding, place Oils B in water bath and heat to 80˚C.
  10. Weigh Waters A and top off with 80˚C distilled water.
  11. 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.
  12. Place in a cold-water bath and mix on low until the lotion reaches 48˚C, ~5 minutes.
  13. Remove from cold water bath and mix in Phase C until fully incorporated, ~2 minutes.
  14. Place the beaker back in the cold-water bath and mix on low until the lotion reaches 30˚C, ~15 minutes.
  15. 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

Comments

  • I think your formula rotted...not became unstable!  There is no preservative, hope you are ok.

    Zen can be added to either phase.  At those low amounts water phase is fine.  In higher amounts I like it in oil phase, cus I have never liked working with  thick water...just a personal preference.
  • Hi @Graillotion, thank you so much for your response. I just realized I have a typo in my formula. The last ingredient is actually Liquid Germall Plus @ 0.5%. I can't seem to edit my original post to change it. But yes there is a preservative in there. 
  • Oh good!

    Just a note on polymerics...if you put them in the oil phase...they do not do their thing until they meet up with the water phase.

    Wouldn't hurt to increase you emulsifier...you have 20% natural oils!  Rather than add just more 165... Consider adding a complementary co-emulsifier like GSC at .75% and keep the Zen.  That is the backbone of all my lotions.

    Glyceryl Stearate Citrate-EMF-GLYCSTEACIT-01 (makingcosmetics.com)

    Don't let the similar sounding words lead you to believe you already have this base covered. :) 
  • Oh this is amazing advice. Thank you so much!
  • GraillotionGraillotion Member
    edited August 10
    You never mention pH?
    If want a chemist answer...you have to give all the pieces to the puzzle.
    Typically a formula like that...will need the pH lowered.  If you purchase an acid to do that....choose lactic. :) 

    Oh...and 'heat and hold'?  Just smiling.



  • Oh so sorry I forgot that. The pH for the two batches I made ranged 5.3–5.4 which I left alone as I thought that was good. Should I adjust up or down?

     Graillotion said:
    You never mention pH?
    If want a chemist answer...you have to give all the pieces to the puzzle.
    Typically a formula like that...will need the pH lowered.  If you purchase an acid to do that....choose lactic. :) 

    Oh...and 'heat and hold'?  Just smiling.




  • So many schools of thought here....but taking it just below 5...sure has some preservation advantages.  Otherwise, not a bad pH.
  • For me only 6% shea butter is more than what i want on my skin. How do you guys like such high amount of oil face?
  • GraillotionGraillotion Member
    edited August 11
    Abdullah said:
    For me only 6% shea butter is more than what i want on my skin. How do you guys like such high amount of oil face?
    WAYYYYYYYYYYYYYYYYY too much for me...but they didn't ask about that.  ;)

    In my richest body product...I use 3% butters, albeit nicer feeling ones than shea. In lighter products for face and hands...I don't go above 1% butters....and only lite oils.  I'm sure you saw all that heavy avo oil as well...I figured it was some kinda eczema lotion.
  • @catanasio Butters and EO are heavy stuff to be emulsified, plus your oil phase is quite large for an O/W emulsion. This makes me think that the 4% of Lotionpro 165 might not be enough (even adding some Sepimax Zen). I'd do one of these things: 1) increase 1-2% of the Lotionpro 165, 2) Add a bit of Steareth-2 and Steareth-21 (0.5-0.75% of each) to help Lotionpro 165, 3) Add a polymeric emulsifier like Sepigel 305 (1-2%). If the product gest too thick, you can always reduce/remove Cetyl alcohol.
  • thank you @ketchito for the advice. I will definitely try this and see how it goes.

  • I think it all boils down to personal preference and what you're used to. I live in an extremely arid climate where most lotions just aren't enough. An hour after applying you're dry again. They're just not occlusive enough. Most people here use butters, which I can't stand that greasy feeling on my skin. Hence my "heavy" formula which definitely doesn't feel heavy on the skin at all. It absorbs quickly and I get so many compliments on how soft my skin feels from dermatologists and other doctors. So I'm pretty happy with the formula I have.
  • You never mention pH?
    If want a chemist answer...you have to give all the pieces to the puzzle.
    Typically a formula like that...will need the pH lowered.  If you purchase an acid to do that....choose lactic. :) 

    Oh...and 'heat and hold'?  Just smiling.


    @Graillotion Quick question on Lactic Acid, do you know there are different labeling requirements when you use lactic acid to control the pH? Someone told me it's considered an AHA which require some disclosures. I'm sure I can just check the FDA website but it can be so difficult to find what you need. thank you again!

  • catanasio said:
    You never mention pH?
    If want a chemist answer...you have to give all the pieces to the puzzle.
    Typically a formula like that...will need the pH lowered.  If you purchase an acid to do that....choose lactic. :) 

    Oh...and 'heat and hold'?  Just smiling.


    @Graillotion Quick question on Lactic Acid, do you know there are different labeling requirements when you use lactic acid to control the pH? Someone told me it's considered an AHA which require some disclosures. I'm sure I can just check the FDA website but it can be so difficult to find what you need. thank you again!

    This page should answer your question: 

    https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-labeling-cosmetics-containing-alpha-hydroxy-acids

    Basically the FDA recommends but does not require certain cosmetics to include a "sunburn alert..." statement on their label if they contain an AHA an the AHA is not an incidental ingredient. The link above will explain it in much more detail.
  • MicroformulationMicroformulation Member, Professional Chemist
    edited August 12
    Cover Waters A and hold for 20 minutes to kill bacteria and mold spores.

    NO. This does not work.

    Use an appropriate grade of water. Use a preservative.
    markfuller@microformulation.com Microformulation.com Microformulation Cosmetic Consulting provides Custom Formulations for both large Commercial accounts as well as smaller entrepreneurs. We can provide Naturally compliant Formulations under the NSF, NPA, Whole Foods and USDA Organic Certifications. BS.Pharm Albany College of Pharmacy, Union University.
  • Unless supplier specifies otherwise I always add all polymeric emulsifiers to oil phase because it makes processing easier. Most of polymeric emulsifiers can be heated but I add them to oil phase after ingredients that need heating are fully melted (and beaker is off heating plate). List of polymeric emulsifiers/thickeners I processed this way without any issues: Zen, Sepinov EMT 10, Aristoflex AVC, Aristoflex Silk, Pemulen Ez4U, Ultrez 30, Ultrez 21.
  • The weird exception from this rule is ‘mysterious’ polymer with the same INCI as ultrez 21 from makingcosmetics called GelMaker Powder. I have no idea what that is because they don’t disclose trade names but it’s definitely not ultrez 21. That one forms a lump that looks like a piece of plastic if heated. 
  • Abdullah said:
    For me only 6% shea butter is more than what i want on my skin. How do you guys like such high amount of oil face?

    Everyone’s skin is different. Mine is dry and I can use cold cream as a moisturizer in winter. In summer I prefer not more than 16-18% of total oil phase. I also use retinoids (either prescription tretinoin or high levels of retinol) so my skin absorbs those seemingly heavy creams as a sponge.
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