Home Cosmetic Science Talk Formulating natural preservative for low ph product

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  • natural preservative for low ph product

    Posted by Szilvia on February 14, 2021 at 1:04 am

    What sort of natural preservative would you recommend for water based product (sort of “micellar water”) which works at low ph (just above 3)? 

    Thota replied 2 years, 10 months ago 6 Members · 13 Replies
  • 13 Replies
  • Szilvia

    Member
    February 14, 2021 at 1:09 am

    I forgot to mention that the formula contains 8% ethanol as well. This can’t be raised.

  • pharma

    Member
    February 14, 2021 at 10:52 am
    With 8% ethanol and pH below 4, you can use more or less all natural preservatives. I wouldn’t go with ferments and herbal extracts from Active Microtechnologies given that they are either a scam, ineffective, or of unknown/dubious composition -> an educated guess would be that they contain lipopeptides and these may not be stable for prolonged periods of time at such low pH.
    You certainly have to define (for yourself) what you consider natural.
    In addition to that, maybe use some % of one or several glycols. They mostly boost other preservatives, may slightly increase viscosity, and give good hydration (except if used in a rinse-off).
    Also, add a chelate. A natural one is phytic acid.
    Going back to the preservatives: The choices you have (i.e. a system which really works) depend on your formulation (ingredients), whether the product is for sales or personal use only, intended shelf life, availability/MOQ, price, and your possibilities to run challenge tests. Using a combination of multifunctionals has the advantage that you can more easily go overkill… though the general recommendation is ‘As little as possible, as much as needed’ and that’s a very good advice when using potentially irritating or smelly preservatives such as formaldehyde releasers, sorbic acid, phenethyl alcohol etc.
  • PhilGeis

    Member
    February 14, 2021 at 1:20 pm

    Good advice from Pharma.  8% ethanol is helpful but not enough.  Decide what you consider “natural” - truely unchange from nature or by commercial redefintion ala Cosmocert.   Might take a look at recent chapter Dr. Amoroso (P&G) wrote on the subject.https://books.google.com/books?hl=en&lr=&id=Xq0CEAAAQBAJ&oi=fnd&pg=PT46&dq=amoroso+natural+preserve&ots=JXysHfmSwm&sig=k6pIcE2zBD9jHdis9VFXAhUnpG4#v=onepage&q&f=false

    But - avoid “as little as possible”.    FDA and EU note preservatives are intended to protect in -use, and challenge tests (USP 51 and it’s ISO, etc. knockoffs)  are not validated,   As you are unlikely to do in-use validation, work within recommended concentration parameters.   Be aware, most of the recalls are “natural” or preservative free products.  Also be aware the natural preservatuves as undefiune mixtures (essential oils, ferments, “parfum”, etc,.) vary from in composition and efficacy from batch to batch.  Grapefruit seed extract is a scam.

  • Szilvia

    Member
    February 14, 2021 at 2:59 pm

    Good thinking, Pharma and PhilGeis. I should give you more information about what I consider natural. I am ok with either natural or naturally derived preservatives. I am not really interested in any natural certifications.

    I was originally thinking on 2% plant based pentylene glycol  and  1-2% gluconodelta as a chelating agent because they are easily sourcable where I live. However I will have a look at phytic acid that you recommended.  
    My other idea was Preservative Eco/geodard etc ( Benzyl alcohol, salicylic acid, glycerin, sorbic acid) but wasn’t sure that would do its job properly at ph3. . 

  • pharma

    Member
    February 14, 2021 at 3:27 pm
    @PhilGeis True, the ‘as little as possible’ is not an accurate measure. I (and likely whoever came up with that phrase some dunno how many decades ago) mean that a preservative shouldn’t be added in unreasonable excess. Correct, the in-use protection requires more than what a pharmacopoeia recommends.
    @Szilvia Salicylic and sorbic acid work best at low pH. Gluconolactone doesn’t chelate as well as phytic acid at low pH but anything is better than nothing. I use pentylene glycol too, kind of a standard for my DIY creations (and it allows me to avoid glycerol).
  • Thota

    Member
    February 14, 2021 at 4:37 pm

    @Pharma
    I am the one who struggles with preservatives, spent number of hours to solve my problem. 
    I own a small brand, presently Use PE 9010.
    around 1-2% struggle with reactions to PE 9010
    I also hear people reacting to ehtylhexyl glycerin.

    I dont like sorbic or benzoic acid due to flushing or reaction they can cause in low pH.

    CHA I tried in the form of spectrastat, it creates warm feeling on skin.

    Dermosoft 1388, havent tried it. But heard that it causes similar reaction to sorbic and benzoic. I am keeping my fingers crossed and really wish it doesn’t cause issues. 

    Phenylproponol combinations are fine but I dont like its smell.
    Phenethyl alcohol, like its smell but havent tried it. I have figure out combinations with pentylene glycol.

    Hoping one day my preservative problem will be solved like magic so that I can formulate without worrying about preservatives. 

    I primarily make water based products, hence more chances of irritation. 
    Also important note that most of the preservatives are fine with emulsions or creams.

  • markbroussard

    Member
    February 15, 2021 at 1:03 am

    @Szilvia:

    At pH 3 and with Ethanol at 8%, you should be just fine using Gluconolactone (and) Sodium Benzoate (1.2%) + Pentylene Glycol (3% to 5%) … both are generally available from re-packers in small quantities.

  • pharma

    Member
    February 15, 2021 at 10:01 am

    PhilGeis said:

    I had a quick glance at that book chapter preview and thereby found several errors. From poor English and formatting errors, over false chemical structures, to simply completely wrong statements. IMHO that book chapter sucks.
  • PhilGeis

    Member
    February 15, 2021 at 10:22 am

    A quIck glance.    I’ll pass on your insightful comments.

  • PhilGeis

    Member
    February 15, 2021 at 1:49 pm

    Back to the original inquiry - please understand major manufacturers have rarely engaged in “natural” preservation.   In context of consumer protection, they’ve found the approach inadequate, and that is consistent with the fact that most of the recalls involve natural/alternative preservative systems.  Few are also willing to engage in the head fake of Ecocert et al.

    Unless your willing to show with efficacy testing (as limited an indicator as that is) an effectvie and stable system - and confirm appropriate compostin of every batch of “natural” preservative, stay out of the category.  You’ll put your consumer at risk for a trivial  claim.

  • pharma

    Member
    February 15, 2021 at 8:04 pm

    PhilGeis said:

    A quIck glance.    I’ll pass on your insightful comments.

    You know that guy?
    Here’s some examples:
    - Geraniol doesn’t have a triple bond
    - Cinnamic aldehyde isn’t a phenolic
    - Quote: ‘TTO is a straw-colored mixture, consisting of a complex mixture…’ LoL
    - ISO doesn’t just define a minimum concentration but a maximum as well. Listing for example sabinene content as minimum in ‘traces’ is nonsensical but <0.01-3.5% makes sense. BTW ISO as well as table 3.1 list 15 constituents and not 14 as mentioned in the text.
    - The text does only imply that azadirachtin, nimbin etc. were terpenes. They’re actually terpenoids = slightly different biosynthetic route. Also, azadirachtin isn’t really antimicrobial (true, most things are, if used at high enough concentrations) but acts against arthropods.
    - Usnic acid would be a new sub-chapter and shouldn’t start with a dot
    - Sub-chapter ‘Herbs and Spices’: Not the best choice for a title if the corresponding table contains almonds and oranges and the like. It’s not wrong but not good either.
    - Citric acid does only act antimicrobial due to lowering pH and/or chelating trace elements, not as proton shuttle like the other listed acids.
    As said, that’s just from skipping over the text.
  • abdullah

    Member
    February 16, 2021 at 1:35 pm

    Thota said:

    @Pharma
    I am the one who struggles with preservatives, spent number of hours to solve my problem. 
    I own a small brand, presently Use PE 9010.
    around 1-2% struggle with reactions to PE 9010
    I also hear people reacting to ehtylhexyl glycerin.

    I dont like sorbic or benzoic acid due to flushing or reaction they can cause in low pH.

    CHA I tried in the form of spectrastat, it creates warm feeling on skin.

    Dermosoft 1388, havent tried it. But heard that it causes similar reaction to sorbic and benzoic. I am keeping my fingers crossed and really wish it doesn’t cause issues. 

    Phenylproponol combinations are fine but I dont like its smell.
    Phenethyl alcohol, like its smell but havent tried it. I have figure out combinations with pentylene glycol.

    Hoping one day my preservative problem will be solved like magic so that I can formulate without worrying about preservatives. 

    I primarily make water based products, hence more chances of irritation. 
    Also important note that most of the preservatives are fine with emulsions or creams.

    At what percentage have you used spectrastat that caused warming? 
    I have used CHA %0.1 with no problem

  • Thota

    Member
    March 29, 2021 at 5:29 am

    At what percentage have you used spectrastat that caused warming? 
    I have used CHA %0.1 with no problem

    I think capryl glycol can cause warming feeling on skin.

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