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Preservative help.
I am using parabens for preservative in cream containing White Petrolatum, Liquid Petrolatum, BHT, Glycerin, Propylene Glycole, fragrance, Cetosteryl alcohol, Cm1000 & vitamin E.
I want to replace paraben preservatives with Ethylhexylglycerin & Phenoxyethanol (mix)
SMP==0.2% & SPP-0.05%
what % should i use of ETHYLHEXYlglycerin & PE2?
IS 0.7-0.8% ok?
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38 Replies
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PE9010 as you know is 90% Phenoxy and 10% CG. (Listed right in the name. 😁 )
Typical top end of the use rate is 1%….so you can do the math.
PE 9010 is weak on YMF….so I would look to address this concern with an additional aide.
Aloha.
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This reply was modified 1 month ago by Graillotion.
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After re-reading my comment….I did not mean to imply….using 1%. With a minimal bug food formula like yours….if it were mine….I would use a total amount of .7 to .8%….plus a boost on YMF. Look at total picture…quality of water, packaging, pH…and mfg GMP.
Since I use a repacker to source my 9010… I add a little more than possibly needed….to cover those aspects. 😅
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This reply was modified 1 month ago by Graillotion.
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This reply was modified 1 month ago by Graillotion.
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Thank you.
we use DM.
Well what about using ehtylhrxyl -0.3% & PE 0.5% Separately.
well 1% mix will also helpful as this moisturizing cream.
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This reply was modified 1 month ago by amitvedakar.
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I see I made an error in my haste…. 9010 does not contain CG….(that is Optiphen). It contains 10% EHG….which of course translates into .1% in formula…assuming max rate of 9010.
The EHG is simply a penetration enhancer. Use of various glycols (longer chain) can also achieve this in formula as well. EHG can and is used at up to 1% in some formulas, especially deodorant products.
Regarding Phenoxy….it is reasonable on Gram - and weaker on Gram +. As mentioned before that package is weak on YMF….so I would be looking for something to bolster Gram + and YMF…if I were wanting to be at ‘sleep well at night’ performance standards. 😴
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This reply was modified 1 month ago by Graillotion.
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what is your suggestion for adding Sodium Benzoat Or benzyl alcohol to boost preservation?
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This reply was modified 1 month ago by
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What is your pH?
Ethylhexylglycerin & Phenoxyethanol reduces viscosity too.
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pH is 6.0
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Basically (with one exception) every organic acid based preservative is going to follow this efficacy curve. I am not very fond of them above 5.5….and would prefer them in the magic happy place at 4.8.
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Here is the skinny on Benz Alc:
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Addressing your question….to bolster 9010… I’d lean towards the Benz Alc at that pH.
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Thank you for taking interest and guidance.
What % do you recommend for benzyl alcohol?
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9010+ipbc+EDTA would work better at that pH
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OK. Thank you. Check Availability of IPBC .
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I’d use a combination of 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, and 2-phenylethanol.
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I’d use a combination of 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol, 2-phenylethanol, and EDTA.
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Why so many diols and why phenylethyl vs phenoxyethyl? Think weak v fungi and staph
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These 3 diols are sufficient as preservatives when used at a high enough concentration (I use around 8% of these 3 diols combined). They serve dual purpose in my formulas as penetration enhancers and preservatives. They also improve the sensory aspects of my formulas dramatically. I add phenethyl alcohol only because of its subtle rose scent. I can still make a fragrance-free claim and the added preservation is a bonus, and it doesn’t impact emulsion viscosity.
I don’t add phenoxyethanol because it’s not needed when I have the diols at high concentrations, moreover I’d like to make a preservative-free claim. Also, phenoxyethanol affects the viscosity of the emulsions. The diols already affect the viscosity a lot, I don’t want to add another one and adjust for viscosity, which leads to a heavier product.
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Add phenylethyl for fragrance and claim fragrance free? Do you think that ethical?
@8% glycol if formulas can take it why again do you need diversity - can you share data?
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1,2-diols with carbon chain lengths 5 to 10 are much more efficient in delivering hydrophilic actives (peptides, amino acids, etc.) into the dermis than propylene glycol and butylene glycol. For instance, 5% 1,2-pentanediol works way better for a variety of hydrophilic actives (for instance, the anti-glycating carnosine dipeptide) than 30% propylene glycol. It also leads to better skin retention of actives (I don’t want transdermal delivery).
I have access to 1,2-diols with 5 to 8 carbons, that’s why I’m using them (otherwise I’d use a combination of 5, 8, and 10 carbon chain lengths). The reason I use a combination is emulsion stability. Caprylyl glycol is a more efficient penetration enhancer at lower dosages but it dramatically blows emulsion viscosity, so I can use only a small amount of it, which is not sufficient for optimal dermal delivery. I don’t use any gums, cellulose derivatives or microplastic polymers because they inhibit dermal delivery. I use only hyaluronic acid as rheology modifier (in addition to fatty alcohols and glyceryl stearate that create liquid crystal structures). That’s why I combine the 1,2-diols in a way that doesn’t destabilize the emulsion, enable efficient dermal delivery, and also produce a luxury sensory output. There is also sufficient evidence in the literature that combining different chain lengths often leads to better skin penetration.
My formulas are way different than what is found on the market. The cosmetic industry cares more about the look and feel of an emulsion than its function. They only moisturize the very top layer of the skin and sit on the surface (which is actually good for a useless product with bad ingredients) and do nothing else.
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I am intrigued to try your formula - do you sell this anywhere?
Between, what steps have you taken to prevent the damage to skin barrier/negative reaction, from your strong move to penetrate the active ingredients?
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The penetration enhancers and the actives are completely safe for topical application at the concentrations I use. I and many other people around me have been using these formulas for over a year with no negative reactions but with positive visible results. In addition to the aqueous serums and creams, I have also developed a novel anhydrous and transparent emulsion that is able to dissolve water-soluble ingredients, oil-soluble ingredients, and ingredients that are neither water-soluble or oil-soluble in one system. This formula particularly contains ingredients that are not stable in presence of water. I have only recently decided to start my own brand and made an agreement with a production facility. The formulas are currently going through stability and microbial tests. In the near future they’ll be available for sale.
Btw, as a continuation of my reply to @philgeis, a high level of occlusion is also important for the penetration of hydrophilic actives. These glycols turn a heavy-feeling highly-occlusive aqueous cream into a light-feeling cream. Each of the glycols contribute differently to this aspect.
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I think you should be more humble and try to do a bit more research on who is giving you the advice. Also, when asked for data, personal experience and suppliers info is not enough.
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@molecularbiologist You might want to read the “Technical document on cosmetic claims (2017)”, where the “free from” claims are questioned, especially the ones on preservatives (I’ve attached an image from the document).
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I’m not taking advice from a person. What I’m telling you regarding the penetration activity and anti-microbial preservation is all based on scientific research. You should be able to easily find the already published papers via PubMed by using the keywords in my messages.
I have a PhD in chemical cell biology and work as a scientist in epigenetic rejuvenation field. Producing cosmetic products could only be a secondary job of mine. I don’t have time or interest in performing skin penetration experiments for a cosmetic product. There is no need to rediscover America. I trust the already published papers on this rather simple matter.
Btw, I also don’t like “free from” claims because they don’t make any sense to me, yet unfortunately the general public seems to like those claims. I also don’t care about natural vs synthetic. I try to choose ingredients that do their job the best without causing any harm to the organism or the environment.
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What Dr Geis mentioned repeatedly (again, check his credentials) is that challenge tests are not meant to replicate real conditions to what the products will be exposed. All the available literature will mention ISO or similar methodologies, and even recalled products that used those systems passed those tests. What big companies like P&G do is giving samples to consumes so they are used and exposed to real conditions, then they recover the samples and only then do the tests. That’s my point on taking advice from a very authoritative voice.
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I see what you mean. The production facility that I made an agreement with didn’t request already used samples for the challenge tests. I can bring this up next time I meet them and see whether they are willing to perform challenge tests on already used samples. I have 6 months to 1 year old samples that have been fingered many times 😀 Thanks for the suggestion.
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No worries 🤓
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sorry for late reply - been traveling.
A PhD in anything hardly qualifies one for cosmetic preservation expertise. Mine is Microbiology and Mycology and my understanding is based on experience and data that are often counterintuitive to conventional technical understanding.
Diols at high levels can exert biocidal activity. I’ve found these incompatible with enough formulas that these they don’t serve product dev cycle time. They can be compromised by consumer practices in use practices more so than classic preservatives. Data rather than a lecture might be better for discussion - but of course you can share data at your discretion.
I was responsible for with environmental risk assessments of P&G beauty products and am not familiar conventional preservative offering relevant risk . Perhaps you can share you data/perspective that responds to harm to the environment as a factor in preservative choice..
Help me on this - you don’t like free-from claims but don’t mind making one for a fragranced product?
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Welcome back, Phil.
You asked me why I use so many diols, and I explained you why. So, the lecture was a response to your question. 1,2-diols serve so many functions in my formulas, that’s why I use that many diols.
I said I have a PhD and a job in X field to explain that I have no time or interest in performing preservation or skin penetration tests myself. I rather trust the published papers on these matters. Having a PhD certainly helps me read and interpret the literature correctly, though. The manufacturer is currently performing stability and challenge tests on my formulas. I’ll let you know if any of my formulas fail. But I’m fairly confident that 8% (1,2-pentanediol, Hexanediol, octanediol) + 0.6% phenethyl alcohol + 0.2% EDTA will pass the tests easily. (based on the literature). My 1-year-old “in use” samples are also doing pretty well at the moment.
I guess you told people in this forum that 1,2-alkanediols are not biocidal and they stop the growth only. Gaillotion made such comments under this thread based on your advice, and I posted an exemplary study demonstrating 1,2-alkanediols can be biocidal based on the concentration and the chain length. As far as I can tell from your publication record and citation number, I guess you work more in the industry than in academia. While it may be valuable to listen to people who have experience in the field, it’s very dangerous to listen to a single person (in this case, you) and believe whatever they say. I think you should advise them to read the scientific literature themselves.
Btw, the new formulations of the Neutrogena Hydro Boost series don’t contain any preservatives. They use (1,2-pentanediol, hexanediol, octanediol) and ethylhexyglycerin. And they use much lower concentrations of the diols in their formulas than in my formulas. Their products are doing pretty well. Just for your information.
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No, as i said it can have biocidal activity esp. at levels ~8%. Never is a long time.
It does not take a PhD to read the literature in this field where experience and data are certainly more compelling. Good for Neutrogena - we do not know the levels and perhaps this is a unique formula where this works for efficacy and formulation - as I noted above. In any case, we do not know the policy and risk assessment applied.
I remain concerned for fragrance free claim re your fragranced product. Would expect from marketing folks but not from technology. Do you make a preservative-free claim for the diol system?
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Aqua, Glycerin, Isopropyl Palmitate, Cetyl Alcohol, Cetearyl Olivate, Sorbitan Olivate, Caprylyl Glycol, Arginine, Carnosine, Alanine, Serine, Threonine, Lysine Hydrochloride, Tropolone, Proline, Maltose, Allantoin, Glycine, Pentylene Glycol, Ethylhexylglycerin, Sodium Hyaluronate, 1,2-Hexanediol, Fructose, Urea, Betaine, Glucose, Trehalose, Glutamic Acid, PCA, Sodium PCA, Sodium Lactate, Palmitic Acid, Stearic Acid, Dimethicone, Polyacrylate Crosspolymer-6, Sodium Chloride, t-Butyl Alcohol, Citric Acid, Sodium Hydroxide, Tocopherol, Parfum.
I don’t see anything unique in this formula. They use olivem 1000 coupled with cetyl alcohol, isopropyl palmitate and Sepimax Zen. They are probably using caprylyl glycol at 1%, which is an effective anti-microbial at this level. They also use smaller amounts of pentylene glycol, 1,2-hexanediol and ethylhexylglycerin for an extra boost. The total amount of NMF excluding glycerin is probably 1-2% only. It’s a formula mainly composed of water.
Yes, I’d like to make a preservative-free claim. But I think I’ll remove phenethyl alcohol because I get consistent feedback that the actives that I use smell stronger than phenethyl alcohol. Should I still call it fragranced because the actives have a scent? 🙂 How do you define fragrance?
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@philgeis
Would you mind to share what’s your go-to, dummy-proof preservative system for a wide range of normal products - especially the new-gen ones?
I am exploring 1-2 Hexanediol, Hydroxyacetophenone and Pentylene Glycol by Symrise. Hydroxyacetophenone takes time to dissolve without heat in some of my cold-processed formulas.
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A few things that are important to know…. I work for myself, so am not directed by marketing departments or even societal leanings or pressures. One of the things I know I could never live with would be knowing a product I made harmed another. That being said, I lean a little bit more to the excessive side. Me like anyone, does not want to smother my skin with preservatives, so I use a lot of multifunctional ingredients that works towards preservation and try and limit those ingredients that work against preservation.
The fundamentals of preservation are:
1) a chelate when possible
2) a final pH that microbes tend to not look fondly on.
3) multi-functional ingredients that enhance preservation, typically by either functioning as a penetration enhancer or lowering aw.
4) Using a preservative based on science that will address all segments that need to be addressed, which are Gram +, Gram - and YMF. Some of these aspects of course overlap…. ie: a chelate will help against mold, etc… etc.
Sooooooooooo… Yes, the Korean brands especially love their hexanediol. Do I use it… yup…but not as a sole preservative. My knowledge is not extensive, but I understand it to be more biostatic than biocidal. Under the tutelage of Dr Geis, I tend to want something biocidal.
I think Dr Geis would be the first to say… you design your preservative system to fit the product. Since I only work with O/W emulsions, I have a pretty pat system. It starts with a chelate…I use GLDA, and if your parameters allow…I recommend you use EDTA. I shoot for a pH of 4.8….but again…this is oft dictated by ingredients, where sometimes I have to stay above 5. I use the Hydroxyacetophenone in everything, but maybe that is more of my ethos….than anything. If at all possible, I try and include both 1,3 propanediol and pentylene glycol. I tend to use almost exclusively PE 9010 as my jumping off point. It has moderate gram + activity, good gram - activity, and poorer YMF activity. So, when using PE 9010 be keenly aware of the weakness package, and address accordingly. YMF is usually easy to pick up….but since some of the ingredients are so pH dependent, it is difficult to address in generalizations. Obviously a chelate starts you in the right direction.
Last but not least… packaging and GMP play a huge role in the success and failure of preservation. I think all would agree….there is no system that will never fail. Hence, we need to give our selected preservation system as much of an upper hand as you possibly can.
I have worked extensively with beginners….and typically the biggest errors they tend to make are 1) believing marketing material. 2) Think marketing mumbo jumbo like ‘broad spectrum’ actually has meaning (it does not). 3) Trying to use organic acid-based preservatives at pH’s where they are simply not functional. This if course is exacerbated by the unbelievable BS marketing language they are sold under. One of the worst at this (will remain unnamed) tells these beginners their organic acid-based system will work up to a pH of 8. There is simply no helping them….when they believe material like that.
Hope this helps…. as I have always shared… view preservation as a ‘system’ and not as an ‘ingredient’. That will help you steer the ship in the right direction. And whatever you do…. don’t believe the marketing material of the sellers.
I used to give the beginners a check list…. ask yourself as you evaluate pieces of the system:
1) What in the formula convinces me I have controlled Gram + bacteria?
2) What in the formula convinces me I have controlled Gram - bacteria?
3) What in the formula convinces me I have controlled Yeast, Mold or the Fungi aspect?
Once you can provide science based answers to those questions… you are well on your way to sending your product off for PET testing and expecting a great result.
Aloha, and Good Luck.
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Love this. You pour your heart and passion for science into replying seemingly trivial questions ❤
PE9010 is my go-to for many formulations, but it displeases some with its mild irritation profile.
When using Hydroxyacetophenone in cold-processed formulas, I have to use a high load of 1-2, Hexanediol + Pentylene Glycol to dissolve it faster. You do like it in your o/w emulsions. Please share with me if you have another way of processing it!
Have you explored the latest Savelite® HB (Propanediol Benzoate)?
Symrise claims that this works strongly against YMF (like Hydroxyacetophenone), and it’s easier-to-use, in liquid with no heat required. I am waiting for their sample!
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This reply was modified 2 weeks, 6 days ago by DearPebble.
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This reply was modified 2 weeks, 6 days ago by
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I might also mention…. I do not do full ‘Aw’ preservation systems, as it takes a rather ridiculous amount of inputs to lower the aw level to a point where it is all inclusive (see attached). That combined with the fact that you are still rather biostatic vs cidal….
See attached….YES, you can kill some stuff with moderate formulation tweaks…. but look HOW LOW you have to go….to kill everything! 😅
Aloha.
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I can’t recall a commercial product taking the risk to do ‘Aw’ preservation system.
Either anhydrous, or build your preservative system properly.
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1,2-alkanediols can be ‘biocidal’. It all depends on the concentration and the chain length. Look, here is a recent study where they individually test 1,2-pentanediol, 1,2-hexanediol, 1,2-octanediol at 5%, 3%, 1% concentrations, respectively.
https://www.mdpi.com/1999-4923/12/11/1117
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Please forget this report - it’s typical of academics playing technologist. The investigator has no record of microbiology, no neutralization step mentioned, no control, everything passed including “sorbic acid” (at A good grief) and no stability testing.
Some diols at high levels can be cidal - in some formulas. One must test their own product hopefully by more than the EDP/EP/ISO bugs (esp. cepacia) through all stabilities and live with those data.
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