Preservative sensitivity in the era of layering.

This is the era of layering. Where we layer atleast 3-4 products. 

I realised using all in one product can reduce the load of preservatives on skin. But we preffer to use many, mist, serum, moisturiser, sunscreen. But all preservatives kill microbes, and by nature they are irritating to the skin. So I am trying to find preservatives which are least problematic to sensitive skin.

Phenoxyethanol seems to be causing issues on skin.
Sodium Bezoate seems to be an irritant too. 
And newer names lesser data. 

Wondering if parabens are least problematic. may be selling 50% glycerin gels and asking customer to apply on wet skin is the way to go?

What are your least problematic preservatives for skin products that go into layering?



Comments

  • I hear your concerns about preservatives. Recently I tested of a product with a focus group of 100 people and approximately 30% described a warming, tingling or burning sensation that we later found out to be caused by our preservative which was Phenoxyethanol.

    A 50% glycerin gel applied to wet skin won't do what you think it would. Without a proper barrier, trans epidermal water loss will occur, hence why o/w emulsions are popular. Chances are, this concentration without a proper barrier would effectively draw water out of the skin, further drying the skin.

    All-in-one in theory sounds great however depending on what kind of actives you intend to deliver, some are better delivered in different steps. Water soluble actives don't penetrate easily and are best applied when the skin barrier is compromised after washing, hence the use of products such as toners and serums. Applying a moisturizer will create the proper barrier to reduce TEWL and lock in water and the water soluble actives.
    Cosmetic Product Development
    Sussex Research Laboratories Inc.
    www.sussex-research.com
  • ThotaThota Member
    Thanks Jonah Ray,

    We make Vitamin C serum, BHA serum, AHA serum, a gel cream for oily skin and a face oil. I know And we recommend layering them at different timings.

    We use PE 9010 in all of them. And max allowed % of phenoxyethanol is 1% in a product. But customers layer 3 products. We suspect the phenoxyethanol load is causing irritation or reactions on sensitive skin.

    We have few alternative optins with Sodium Benzoate and Benzoic Acid like, 
    • Sorbitan Caprylate) and propanediol, Sodium Benzoate (nipagaurd sce) Ph 4-7
    • Gluconolactone, Sodium Benzoate, Calcium Gluconate - Geogard Ultra, pH of 3.0 to 6.5
    • Benzyl Alcohol, Salicylic Acid, Glycerin, Sorbic Acid - Geogard ECT 

    Wondering if benzoic acid preservatives cause lesser reactions than phenoxyethanol. Did anyone have any idea with this.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @thota:

    Sodium Benzoate can cause a skin flushing reaction and Benzyl Alcohol can be an irritant, so your alternatives are not really good options if you are trying to substitute preservatives to avoid skin irritation.

    Perhaps you could consider something like Honeysuckle Extracts:  Lonicera Caprifolium (Honeysuckle) flower extract, Lonicera Japonica (Honeysuckle) or Minasolve Green A:  Pentylene Glycol + Phenylpropanol
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • Vitamin C serum (LAA?), AHA peel, BHA peel are all supposed to be low pH products. PE 9010 doesn’t perform  well under low pH.
  • SpongeSponge Member
    But all preservatives kill microbes, and by nature they are irritating to the skin.

    Perhaps a bit of a false premise? I’m not debating that certain preservatives irritate certain individuals, but the way it’s written it reads “preservatives (by method of killing microbes) irritate the skin.” As in, antimicrobials irritate skin solely based on the fact they’re antimicrobial. Hope I’m making sense. 

  • ThotaThota Member
    Sponge said:
    But all preservatives kill microbes, and by nature they are irritating to the skin.

    Perhaps a bit of a false premise? I’m not debating that certain preservatives irritate certain individuals, but the way it’s written it reads “preservatives (by method of killing microbes) irritate the skin.” As in, antimicrobials irritate skin solely based on the fact they’re antimicrobial. Hope I’m making sense. 

    This is what I read somewhere and believed it to be true.
    Also I wonder if the skin flora is disturbed by preservatives.

    Hope I really find non irritating preservatives.
  • ThotaThota Member
    Vitamin C serum (LAA?), AHA peel, BHA peel are all supposed to be low pH products. PE 9010 doesn’t perform  well under low pH.
    We make SAP serum at pH 6.5 and now trying to replace phenoxyethanol as one of the customer experienced a reaction to it. 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Yes, of course, preservatives in products will also affect the microbes on the skin to some degree, but that does not mean that the preservative will be irritating to the skin.  And, the skin biome recovery quickly from any disruption. 
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • ThotaThota Member
    @MarkBroussard thanks for the inputs
    I dont have access to honeysuckle extracts and their prices too high. 
    Pentylene Glycol + Phenylpropanol I have access to but havent tried them.

    I make all oil free gels with Ph ranging from 3.8 to 6.5.

    I was considering Ethylhexylglycerin and can u tell me what other preservatives will complement it?

  • ThotaThota Member
    Also I have access to blend Ethylhexylglycerin and caprylyl glycol. wondering if it is standalone. and would it better if I take them separately. 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Cap Glycol / EHG is a standard blend ... you can purchase pre-blended from Makingcosmetics.com for small quantities to test.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    Provides Formulation Development and Lab-Scale Contract Manufacturing Services.  See website for details www.desertinbloomcosmeticslab.com

  • DoreenDoreen Member
    edited April 19
    @Thota
    It seems that sodium levulinate and sodium anisate (Dermosoft 1388, Dr. Straetmans) should also work well at a pH of 6.45. I read it in this article, written by a cosmetic chemist. Very interesting. Apparently these salts don't even need to convert to their acid forms to be active!

    Dermosoft OMP from Dr. Straetmans (Methylpropanediol, Caprylyl Glycol, Phenylpropanol) could also be an option. It's pH independent.

    Good luck!

    Edit: Dermosoft 688 (p-anisic acid) works from pH 4- 6.5 according to manufacturers data.
  • PerryPerry Administrator, Professional Chemist
    Just use parabens. They will be the least problematic and they have decades of demonstrated proof that they work. 
  • DoreenDoreen Member
    Perry said:
    Just use parabens. They will be the least problematic and they have decades of demonstrated proof that they work. 
    I totally agree.
    I suggested Liquid Germall Plus and Germaben II in another discussion to @Thota, but maybe their customers don't want parabens and/or formaldehyde releasers?
    I myself have a very sensitive skin and I too layer several leave on skincare products and use parabens all the time (and formaldehyde releasers). My skin tolerates it very well, no problems at all. The only preservatives I very obviously react to are sorbates (with skin flushing) from concentrations of about 0,12% and higher.
  • ThotaThota Member
    @Perry, Sadly customers are half educated these days, I would love to use parabens, but I dont want to take a risk of consumer perception. As small brands those will be our differentiating factors.

    @Doreen, dont know if Germaben I and II are better tolerated than phenoxyethanol. Some of my customer base are like natural soap and Oil kind of women and some of them are totally into 5-6 step routine. No wonder they react to water based stuff with preservatives.

    And thank you so much for the Sodium Levulinate info. Sounds very promising to me. Also wondering if my pH 3.8 lactic acid serum needs a preservative. I read that acids are preservatives but didn't hear anything about lactic acid. 

    And I have made a trail with Nipaguard SCE, My otherwise translucent gel turned to opaque white gel. But its so affordable. INCI: Sorbitan Caprylate, 1.3-Propanediol and Benzoic Acid.(benzoic acid at 0.15%).

    Next trails will be with below Sensiva blends from Schulke,
    1. Phenethyl alcohol, Ethylhexylglycerin 
    2. Phenylpropanol, Propanediol, Caprylyl Glycol, Tocopherol
    3. Phenethyl Alcohol (and) Ethylhexylglycerin
    4. Propanediol (and) Phenethyl Alcohol (and) Undecyl Alcohol (and) Tocopherol
    Hoping EHC and caprylyl glycol are problem free, But in some studies they proved to be irritants when used with Phenoxyethanol. 
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