PhilGeis
Forum Replies Created
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@Dazed
Think both are prob ok - with Sodium benzoate rather than Benzoic acid. I prefer the 1st as I’ve seen more stability issues with sorbate.No sure what natural leaning means - what would be the claim?
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Pump is good. Prob need something for Gram + bacteria and fungi.
What is your target pH? -
I understand and filling maty be a challenge. Tube, tottle, flexible capped package - ?
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Powders often require preservatives. Consider please that they take up moisture under humid conditions such as a humid bathroom. In this, the greatest risk is fungal growth. Micro quality of your materials is also important - esp. the clay.
Dynamics of pH will affect Nabenzoate efficacy and those are hard to anticipate. Propyl parabens, chlorphenesin might be some options, if needed. Look at labels of similar products. -
@Perry
Boy Perry - think this guy makes some odd statements..
Benzyl alcohol - 2% is well beyond typical use levels and Eu limit is 1%. It’s pretty weak vs Gram + bacteria and oxidizes primarily to benzaldehyde and an almond odor. It could further oxidize to benzoic acid but no way enough to preserve.
Cap glycol would be weakest vs fungi and should be a booster, not a stand alone or a central element. -
Jar for a hair product.
Used too near the shower and sink - will very likely collect a (tap) water layer that no amount of preservative in product will preserve. -
Here’s the link - https://www.jidonline.org/article/0022-202X(86)90008-4/pdf
I’d not get carried - no standard deviation in this or Fig 1. -
Think so - give a test.
What’s packaging? -
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.