PhilGeis
Forum Replies Created
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Lower EDTA concentration to 0.1-0.2%
Suggest adding preservation vs fungi and Gram positive bacteria.
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I understand and don’t find that so useful. We’re working in dynamics of formulas, microbes and consumer use. There is some degree of consistency/predictability and it more Edisonian than formulaic - derives from efficacy in formulas in use. Most folks here don’t have the luxury of on-demand validated challenge testing and post consumer use survey so they’re best advised to reapply the basic stuff within identified safe in use ranges.
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So you don’t think I’m just blowing you off on this, here’s an example.
Challenge test revealed that benzoate consistently added a lot for preservation of surfactant products, esp. at pH (7.5) well above benzoic acid pKa. We’ve known this for many years before it was described and technically addressed in the literature.
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Glycols and phenoxy are weak vs fungi.
Highly recommended? Maybe the supplier but doubt anyone familiar with preservation would recommend glycerol caprylate
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I know some have found sorbic/benzoate good but it’s generally weak vs Gram negatives. Phenoxy+ is good v Gram negatives but weak vs Gram + and fungi. Ypu best off with a combination of the 2 - esp. benzoate and phenoxy+
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Neither is that great - Verastatil the the weakest - its pH range is prob driven by concerns for pH driven hydrolysis of its fairly-useless ester.
the 2-12 is absolute BS and should eliminate your consideration of that supplier.
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This reply was modified 2 months, 1 week ago by PhilGeis.
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This reply was modified 2 months, 1 week ago by
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consider benzoate, parabens.
can you describe product and formula?
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It was not simple technology - early versions left hair pretty ugly. P&G worked on it for years.
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Adding to fareloz’s good points, I understand these folks allegedly will check a product if you ask, and the primary appears to be promotion of the site. Saw no protocol for products selected for recommendation. Can’t get details of specific products without logging in. Site was licensed by Mayo, to HER and run by EmpowerHer - mission: “empower women to achieve her (sic) goals”. Makes me wonder if the many small brands reco’d involved multiple agendas.
Invested a few minutes in examining recommended products to find one consisting of 100% “organic” castor oil rated 100% Top Allergen Free). Note - “Applying pure castor oil to the skin can cause irritation and allergic reactions like contact dermatitis,.” https://health.clevelandclinic.org/castor-oil-benefits. Guess they’re working from Mayo’s list rather than risk assessment per se.
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I’m with fareloz. Answer is no.
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Unilever cosmetic microbiology is pretty good. Not know pH, package, ingred. preservatives, balance - I’ll note benzoate is more effective with some surfactants
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Doubt a concern unless you plan to hold it.
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Happy New Year!!
Benzoate’s effective pKa can be uncreased with some surfactants such as SLS - efficacy up to and > 7
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I don’t think you should have any issues. what is max temp you estimate?
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Phytate works in many applications. I’d let the challenge data guide you in this.
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mention my name
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Here’s the guy -
Gerald B. Kasting
Professor Emeritus of Pharmaceutics and Cosmetic Science
James L. Winkle College of Pharmacy
University of Cincinnati
513-484-6474
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I’ll make some calls.
btw - it’s :”Phil”.
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Good point with the permeation enhancement. Whatever preservative goes on skin will go into tissue. To that, there are very little data for any preservative with the exception of paraben. Parabens do permeate and are impacted by esterases in skin and tissue. A CDC study - a good one as in not Darbre quality - found parabens at exceedingly low levels in urine of typical men. Cosmetic industry generated a lot of sound data that was not published for parabens uptake and excretion that defended typical use. I’m not toxicologist enough to address the concern with assurance but gut feel would look to preservatives used for injectables. I could hook you up with someone if you want.
I’d stay away from the marketed combinations. They’re organized for unique marketing positioning if not patent protection, claim unjustified broad spectrum and wide pH coverage and presume safety of the combination rather than confirm. In context of greatly enhanced permeation, I’d trust none.
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In a micro sense - BHT is not relevant but you should add a chelator - esp. EDTA.
No one can guess at your challenge data. Let challenge testing guide your system - your system is not “too much” as the constituents are within the accepted safety in use ranges. You should not titrate to just barely passing whatever protocol used.
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CMIT is stabilized with a Mg salt - if diluted and held in water, CMIT is unstable as the Mg salt is diluted. I don’t know if the same happens in another polar solvent like a glycerol. If you have analytical of micro capabilities - you can check. Otherwise contact the folks at Arxada and ask.
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Gram negative bacteria have always been the primary contaminants of cosmetics. They are the most commonly found bacteria in water - whether pristine snow melt in the alps or process water in a drug plant. They are also the most adaptable. resistant to preservatives, antibiotics, disinfectants and can metabolize these and almost anything ss carbon and energy sources. Cepacia is the classic example - it has a bunch of copies of its DNA and picks up genetic i-from other bacteria.
https://www.nature.com/articles/nrmicro1085
nature.com
The multifarious, multireplicon Burkholderia cepacia complex - Nature Reviews Microbiology
The Burkholderia cepacia complex (Bcc) is a collection of genetically distinct but phenotypically similar bacteria that are divided into at least nine species. Bcc bacteria are found throughout the environment, where they can have both beneficial and detrimental effects on … Continue reading
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there’s almost no preservative or product poor manufacturing can’t screw up.
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Don’t know specifics - historically these have involved plastic particles in product, rodent droppings/mold from water ingress in warehouse.
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Sorry -meant increased (not uncreased).
and I’ve noted this in preservation of surfactant-based personal products - shampoos, hand wash