PhilGeis
Forum Replies Created
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What is pH? Why both benzoate and benzoic acid? Think I’d check on in-use contamination risk - this will be inoculated at every use.
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Try them - they’ve been around for a long time and there’s a reason you see little use - they don’t work well. Watch the pH - their pKa’s are around 4.5. Please don’t engage with Cosphatec’s dishonest “multifunctional” dodge.
Toothpaste is irrelevant to other cosmetics - formulation is generally hostile with flavoring agents, Aw and some with benzoate or parabens. Packaging is protective.
USP is a poor determinant of micro safety and the others not much better. None of these is validated to protection in consumer use - the primary purpose of preservation - and you’re clearly playing at the edge of efficacy even for those.
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True Bill - alcohol with quats can be effective combination.
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Multifunctionals? Those are (weak) preservatives, and multifunctional here is a head fake to the Directive.
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A formaldehyde releaser with 2/1 Methyl/Propyl was the classic preservative combination for emulsions for 30 years. Combine with a solvent like prop glycol or in heated water phase - not in oil phase. Partitioning can be an issue and should be addressed.
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I’ve used 2/1 and 3/1. Propyl has comparatively limited solubility and considered more effective vs. fungi.
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DaveStone said:
Good points. Although I would think a big company might not use an ingredient simply to cut costs.
I assure that a big company would use an ingredient simply to cut costs. Consider millions of units sold globally for years - a couple of pennies per unit is worth pursuing.
To the paper - please understand reports of “significant” differences versus controls in controlled protocol may not - often do not - amount to benefit in product application and there was no comparison to ingredients currently used. Don’t forget that academics often exaggerate impact of their work.
Further, use as sunscreen would require new drug approval.
Above doesn’t mean folks wouldn’t use a n ingredient just for the “story”. Most of cosmetics are sold on hype. -
ethanol at 20%
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I like any of the three to the left
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For fungi, parabens or IPBC are best - you could try Caprylhydroxamic acid.
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Parabens or IPBC are best - you could try Caprylhydroxamic acid.
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You should design a system for broad spectrum efficacy and test to confirm. Phenoxy has little effect vs fungi and ok but not great vs Gram positive bacteria.
Phytate is pretty good as is EDTA.
Open jars are risky but if it’s for personal use - it’s your risk only. -
Oatmeal products are difficult to preserve. Can absorb oils so important to understand stability even if preservation initially effective.
9010 by itself is not enough - suggest chelator addition, and you’ll need addition with antifungal efficacy.What package design do you anticipate using?
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will you use parabens or IPBC?
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As Abdullah noted - you should establish antifungal efficacy in your preservative system. “Broad spectrum” claim for 9010 is the usual marketing BS.
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Have you ruled out microbial contamination?
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Please look at the specific monograph - some do require specific testing - e.g. spf determination for sunscreen products.
see monographs at https://www.accessdata.fda.gov/scripts/cder/omuf/index.cfmI gather you’re concerned with the skin protectant monograph - that does not specify testing.
https://www.accessdata.fda.gov/drugsatfda_docs/omuf/OTCMonograph_M016SkinProtectantDrugProductsforOTCHumanUse09242021.pdfFurther - please understand these are drugs products and must comply with relevant regulations under 21CFR for registration, GMP’s etc.. A product can also be both a cosmetic and a drug and comply to both sets of regs.
https://www.fda.gov/cosmetics/cosmetics-laws-regulations/it-cosmetic-drug-or-both-or-it-soap -
True soap-based shampoos were replaced by synthetic surfactant-based products in the 1930’s.
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Assume you’re looking at the skin protectant monograph.
What is your intent for the glycerine use? -
By definition, “intent” establishes a drug product. Product claim is the most obvious indicator of intent. As Rockstargirl noted - and you see it in antiaging products with wrinkles, etc. - addressing “appearance” can be a means of maintaining cosmetic status.
In US, simple “soap” (as the metallic salt of a fatty acid) is an article regulated by EPA and CPSC not a cosmetic. Surfactant based soap is a cosmetic.For OTC drugs, read the relevant monograph. Some require testing to confirm efficacy. https://www.accessdata.fda.gov/scripts/cder/omuf/index.cfm
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pH 6 with sodium benzoate?
Micro may not be the source of your immediate concern - but that is a useless preservative system. -
Antimicrobial toilet paper (Triclosan).
Might add any/maybe all of the latest Microban applications. -
[PDF] Prevalence of Moderately Halophytic Aerobic Gram Positive Cocci in Bath Soap Bars wS Témoin‐Fardini, J Servant… - International Journal of …, 2017 - Wiley Online Library
… strain DSM-12544 purchased was not able to predict the ability of contamination of an
alkaline soap, the wild-type strain Nesterenkonia lacusekhoensis 768 was chosen to be our ‘…[PDF] academia.eduith Special Reference to Nesterenkonia Species
Z Bhathena, N Barchha, TK Sivaram - academia.edu… Thus, in this study 20 unbranded soap bars available in local … to the lesser known
Nesterenkonia species, an alkalophilic … closely related to Nesterenkonia species. Thus, survival of … -
I’ve no specified number. My experience has been in shampoos and hand wash.