PhilGeis
Forum Replies Created
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Think the pentylene glycol is not necessary. Benzyl should work vs fungi. What is pH?
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Yup - I put it in many of ’em.
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Think so
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@Pharma
I’m with you! The “scientific ” cosmetic journals publish much shallow dreck. take a look at this “pilot study” for one,https://onlinelibrary.wiley.com/doi/abs/10.1111/ics.12802
Steinberg’s book is good - but looks at conventionals. -
Sure - the microbes need water and the sugar sucks up the water so it’s not available. Pseudomonads are water bugs so they need the most water and are most sensitive. staph grow on skin where there’s less water and molds need even less.
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@Newtoformulating
What’s the product type/general comp? -
Aw is a tough one. Even at levels so great bugs can’t grow - they still survive. Sugar - sucrose - would have to be about a lot! 70%, would approach 0.8 Aw. The absolute cutoff is about 0.60 so some mold could still grow. Those that could grow would do so slowly - but ISO 29621 set the cutoff for Aw as cosmetic preservative at 0.7 0
For comparison, honey is about 80% sugar, pH 3-4 and reportedly carries some other stuff bugs don’t like a little H2O2, peptides.
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Tocopherol is typically used with benzyl alcohol to limit oxidation.
Mikrokill COS + EDTA is ok for leave on. Would prefer EHG with phenoxy but Cap glycol can’t hurt. There are better combinations for surfactant-based products.
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For the microbiology of cosmetics - from preservation/global regulation safety of preservatives/process and manufacturing hygiene - suggest Cosmetic Microbiology a Practical Approach , 3rd ed. 2020, CRC Press. AND
Preservatives for Cosmetics 3rd ed. 2012, Allured Pub.A grain of salt with articles from cosmetic-focused journals . Too many articles from half-smart academics and self-promotional “professionals.”
For trade magazines like Cosmetics and Toiletries and Happi, more than a few grains. -
In product or process - unstable @ alkaline pH-esp. with amines, oxidizing and reducing agent, in dilute aqueous solution. Do not use in leave on products. Best with EDTA and needs some help vs. fungi.
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as Perry said - you’ll very prob not get bothered.
Why are you adding the stuff - what is your “intent”? “Cosmeceutical” has no regulatory meaning - and not much in reality. -
Wouldn’t the Na salt be more cooperative?
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How hard is your water - in-use.?
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Perhaps a fungal gap, less so Gram + but it’ll prob pass USP 51. Why mult. glycols?.
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OK. You describe an excellent system - in almost all the Pantene, Aussie, Head and Shoulders, Old Spice, Ivory, etc. for decades.
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Think it’s BS. Like all the true naturals, essential oils, hydrosols, etc. - the composition will vary greatly - individual constituents by orders of magnitude- between batches. So even if parabens, and analysis can be flawed in these reports, you can’t count on it.
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Not familiar with Euxyl K12.
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I’d not sue a contaminated raw materials. FDA would consider the product itself adulterated whether it grew bugs or not and it might even after release.
Appreciate your professional attention to hygiene and quality - I’d sure keep it up!
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@Anca_Formulator
The primary purpose of preservative is to protect the consumer during continued use the the product. This is reflected in the very flawed concept of period after opening. That means your preservative must be stable through that period whatever the chemical stability may be.
“Retest” or recontrol testing (assume for micro) may just be boiler plate - or that they’re no confident in the micro stability of the material -
What do you k now about its safety?
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Guess they’ll next label apples, pears, plums etc “contains formaldehyde”
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That’s exactly the issue - there’s nothing about this other than Inolex promotional claims including the unjustified “natural” for what is very likely another synthetic material. No efficacy and just as important - no safety.
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How will you justify safety of the new ingredients?
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Just phenoxyethanol. That is a poor system. You’ve nothing to address fungi. Please understand, merely passing a challenge test is not enough - such tests are not validated to anything.
You should design a system vs bacteria and fungi and then test to confirm expected efficacy. -
Sorry - my comment was confusing - parabens/EDTA WITH chloromethylisothiazolinone.
Parabens./EDTA alone is not - but good addition to chloromethyl isothiazolinone that is excellent vs bacteria, esp. Gram negatives.