PhilGeis
Forum Replies Created
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tens of seconds to 1 minute on a clean surface
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ketchito is correct, and P&G has relied on that phenomenon as a an element of preservation for most of its shampoos - but typically with EDTA and an isothiazolinone or benzyl alcohol. Not aware salicylate at its pKa would help or shares the surfactant interaction phenomonon.
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All those. - everything that touches product.
Alcohol is best for surfaces and small objects - that should be cleaned before santizatiion and covered until used. Tanks, lines, flow paths best with heat (hot water or steam ) and in an assembled florm through proess.. Chemical sanitization (hypochlorite) requires rinsing and that demands high standrd foir rinse water. -
Piroctone is a chelating agent. As a hydroxamic acid like Pyrithione Zinc, it has antifungal function.
This explains https://findanyanswer.com/what-is-the-pka-of-a-drug
The protonated acid is the active antimicrobial. DHA pKa~ 5 - so 50% dissociated at pH a little over 5 (haf proitinated, half ionized - salt). Higher pH shifts to dissocated/ionic salt that is not active. In product, other ingredients may effectively change pKa - e.g. benzoic acid and surfactants. -
Sanitization to kill microorganisms, esp. those that can contaminate product. Many use alcohol - esp. 70% ethanol.
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Acetic acid is not a preservative - except as an acidulant.
Abdullah. It’s has chelator function like ZPT, not so cost effective as a preservative and has found little use in that context. Don’t think it’s on the positive lists. -
Do you guys get much analytical composition data with your essential oils?
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Consider Phenoxyethanol - for that there is a lot of data for EHG boost. I’d be cautious re a sales rep’s suggestions for their own products. Think you may have a fungal gap. Perhaps add an organic acid.
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How do you sanitize?
How would your op’s commpare to these guidelines? https://www.fda.gov/cosmetics/cosmetics-guidance-documents/good-manufacturing-practice-gmp-guidelinesinspection-checklist-cosmetics -
Why do you need Hexamidine? You’ve got two others
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What is the microbiological quality of your manufacture?
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Neither is esp good. Suppose your policy prevents isothiazolinone. I’d prob use #2 and add EDTA and NaBenzoate. Better check stability in PET. Suggest ISO AET with added cepacia.
What is your making risk?
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Don;t see much benefit with DHA when you’ve Benzoate, esp. in a surfactant context.
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Answer to specific question is neither - they’re both just phenoxy with a little extra boost and each could be argued a little better than the other. To get a functional answer re. a complete system, you’d need to include product formula, package and making quality dynamics.
As Microformulation said, challenge test is metric. That’s all you have, but it’s not validated to making or consumer use. FDA enforcement reports - no doubt every cosmetic recalled passed a (at least USP) challenge test. It’s a price of entry but good and poor systems pass - and the very great number of recalls in recent years is primarily associated with this prob pass and certain primary reliance on politically-correct, marginal preservatives. I’d classify as such cap glycol, glyc caprylate and other esters, PEA, EHG, cap hydroxamate, gluconolac tone, etc. Maybe not only due to the preservative systems - alone they’re poor but the typically small to moderate sized companies recalling products likely have a poor understanding of micro risk control in formula, package and making context.
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Caprylhydroxamic acid is not that good as a chelator in preservative context.
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It’s the single best preservative booster.
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Amen, Microformulation
Abdullah, Piroctone Olamine and HCl? Your antidandruff active and pH adjustment, respectively?
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As Pharma said - and neither is esp good vs fungi. nor shlould be considered a complete preservative system.
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Yes - at the right pH and with EDTA or a good chelator
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That is a poor preservative system and your supplier is profoundly ignorant. Suggest you look for alternatives to both.
Food colors have nothing to do with the acid salt equilibrium that is prmarily controlled by pH in cosmetic systems.
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It does - pH 4 is not prohibitive.
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Sorbate would not suffer a different fate than benzoate. Prefr benzoate due to stability and general use in many shampoos largely due to synergized efficacy with surfactants - and my experience. I like it with Kathon but i know that bothers some folks
DHA is merely another organic acid.
I’m not so familair with Phenylpropyl - it’s not in ester worry but also not broad spectrum.
Fungi are very rare contaminants of shampoos. Phenoxy works well with ethylhexylglycerine - good idea. Maybe those with benzoate and EDTA.Whatever you do, let us know how it fares in challenge.
Good luck!! I’d say Semper Fi - but I was just RA.
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What’s pH?
I’d drop the DHA and sorbate in favor of Benzoate and Gluconolactone as you have EDTA (target 0.1%). The esters are vulnerable to pseudomonad esterases. as pseudomonads are primary risks for shampoos, this is a pretty weak system. What about some benzyl alcohol. -
What is your pH? Suggest you contact supplier for stability concerns. 24 hours is plenty of time for background contamination to grow.
I’d not trust the humblebeeandme combinations. Some are pretty poor.
Suggest you look at preseservative systems used by major marketers.