PhilGeis
Forum Replies Created
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Failed twice? Two batches or did you repat the intial test?
That is not a “Hurdle” - propane diol at 3% is not effective, pH 4..8 is well within the susceptible range. Evonik - phytate? is ok.
To have a hit in QC - it’s got to be pretty bad and not comes with poor preservation but also compromised manufacturing. To address the former - can you used benzoate, benzyl alcohol what else is in your corp. policy? But please address manuf issue - have ID”d a prob cause and CAPA completed?
btw - What is technical basis for ex and PAO dating? What is your dist and shelf timing and do you really expect consumers record and to toss it at 6 months?
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“Failed” - in challenge or manufactured QC?
That is silly system and not only likely contributor to this failure - certainly high risk for failure in consumer use whether it passed in challenge or not..
Describe your hurdle, please.
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If they dont know 61/62 - wonder what they mean by knowing USP. There aren’t many other micro methods in USP. Show the methods - they’re online , can they run them?.
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No! EWG Verified is BS! P&G’s products that used this in marketing are worth a look.
Benzoate is a good addition in shampoos - and benzyl alcohol/benzoate/chelator a good combination. But test it.
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P&G also invested heavily in Malassezia - dandruff etiology research after some folks from Pateur Institute figured out the taxonomy and biology of the relevant fungi. That was for advertising and professional “credentialing”
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Include Benzoate in any system - tho not enough on it’s own - its pKa is effectively lowered by typical shampoo surfacatnts. Not aware that tossing in other organic acids is that helpful but prob can’t hurt. Neither system is that great vs Gram negatives - so you might run challlenge testing diluted (50%, 70%) to get a feel for manufacturing/consumer risk.
Also take a look at preservative system in products P&G recently marketed with EWG (gack!).
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To ketchito’s point, P&G’s research and application re. Head & Shoulders/Wash & Co - considerable effort re. ZPT particle size, coacervate in formula and deposition technologies go into the product.
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Mike - your experience does not limit microbial contaminaton and some of the bugs that contaminate are not readily detected and products not accurate evaluated by routine methods. From liquid laundry (Halomonas and Pseudomonas aeuginosa) to liquid cleaners (Pseudomonas aeruginosa) to soap (Nesterenkonia) - recalls and publications document susceptibility of higb pH products..
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and all thse products were released based on in spec micro content testing
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Do you refer to stability? Finctionality?
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“Water is mixed with the dimethicone” - dimethicone oil in water is more readily preserved to pass a challenge test and may still be at risk in consumer use. Water in dimethicone oil emulsion will often fail challenge but is typically much more robust in consumer use.
Silicone oil emulsions are classic exceptions to conventional reasoning.
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Polysorbate complicates - at that level you may be neutralizing preservatives Don’t worry about carbon source - you’ve enough already and the relevant bugs can grow in disitilled water.
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To the aticle, only profoundly obscure journal publishing without useful review routine preservative testing data (probably old) from a contract lab reagrding one simplified formula. This is less than most sales borchures offer for Leucidal et al.
Please design a system that should be effective (Gram neg and pos bacteria and fungi) and confirm efficacy. Simply passing a USP 51 with whatever means little - virtually every recalled formlua passed the test. Look at competitve prodhuct
Gram neg - glycols are ok but you need more - phenoxy/EHG* is much better - esp.. with chelator EDTA. Gram +’s and fungi are not so bothered by glycols - phenox helps some for Gram +’s. Parabens could work vs. both but you try orgnaic acids if pH permits. IPBC (for fungi) ,Chlorphenesin might work.
What’s fornula and packaged.
*EHG is a booster esp. with phenoxy - useless alone
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That’s a poor presrvative system. Neither USP nor ISO simulates anything in use - they’re just tests that show some efficacy conventionallypresumed to justify marketing.. The latter has more demanding “pass” criteria (hopefully you satisfy A). Don’t know what pump certification means but “fail” means you fix the preservative system - not hide it in a pump paclage..
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Preventing fungal ex[ppsure is prob impossible as they’re (spores) ubiquitous but Fusarium and only Fusarium is odd and recalls Buasch & Lomb disaster. In local marketing Fusarium (and only Fusarium) in consumer use - not in QC. Expanded marketing without fix was disaster to company, employees and stock holders. e.g. https://levinlaw.com/practice-areas/renu-recall-bausch-lomb-eye-injuries
Leucidal was a bad decision as is “nontoxic, non allergic, hypoallergenic” - for which there is no preservative or ingredient.
Some questions - Do you see Fusarium in QC? Is this a water in silicone oil emulsion?
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This is from a formulator. Yes they do apply - and think you’ll likely find a relevant patent.
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It indeed is and as we’ve discussed, one of the bugs that characteristically contaminates soap is not readily detected by media used in conventional testing. Consumer contamination is another matter for which I understand few have the understanding and resources to address this aspect. of product risk
The larger issue is this - alkaline pH short of 11+ is not a barrier to contamination.
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Any fatty-acid based soap. P&G advertised its Zest against its own (but unnamed) Ivory soap. Lever advertised its Dove vs the same (also unnamed) Ivory for “mildness”.
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That’s a couple of weak organic acids with an ineffective organic acid and a weak unstable chelator. Even at a favorable pH </~ 5.5, that’s a poor system.
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Syndets last century were marketed on the basis of eliminate soap scum the hard water Ca salt of soap fatty acids - and were less irritating than C12 coconut fatty acid bar soaps.
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Surfactant solutions at pH 9-11 are susceptible to microbial contamination.
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what’s the pH and surfactant? maybe an orgnaic acid could fit in
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btw - might add the Fusarium to your challenge test
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“Mixed” - presume dimethicone is not water soluble is it 2 phase or emusified?
Storage or bottle printer - you might put out settle plates but isn’t the product in closed packaged by these operations?