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Sepinov EMT gel breaking
Hi everyone,
I need some help, please.
I made a simple gel formulation today that failed as soon as I tried adjusting the Ph. It looked perfect until I added the preservative. It thinned out a lot. PH was above 7 so I used citric acid. With one drop, Ph dropped to 3.9. I tried to adjust back up. There the viscosity was destroyed (broke/gone) completely. From then on any effort to save the gel was lost. I’m not quite sure why the Caprylyl Glycol would thin out the product and why PH adjusting would break the viscosity. Sepinov can tolerate Ph 3 to 10. Also don’t think any of the below contain electrolytes. Please help me troubleshoot this as I am planning to throw in a bunch of actives later. Thank you.Water:
Glycerin: 2%
Propanediol: 3%
Butylene Glycol: 3%Sepinov EMT: 0.5%
Esters: 2%Caprylyl Glycol Ethylhexylglycerin: 1%
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27 Replies
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Citric acid and the base used to counter-act the low pH are electrolytes, especially when reacting with each other
. Citric acid is probably not your best choice, try lactic or hydrochloric acid and try not to play yo-yo with pH. -
coco said:s I am planning to throw in a bunch of actives later. Thank you.Caprylyl Glycol
Yes…get you pH lined out as soon as you have your water phase complete. You can always adjust again later, if it requires. And as said above…lactic is so much better any many ways…your skin will thank you.
And CG is well known for wreaking havoc on viscosity.
But when you say a bunch of actives later….guessing some of these will also break a polymeric emulsion.
🙂 Good Luck.
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I will try that out! Thank you guys! @Pharma @Graillotion
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Please consider a more effective preservative system - whatever the stability.
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@Pharma @Graillotion
I am actually trying to make an 3-5% Azelaic acid serum with this. Sepinov supposedly can support some AHA solutions up to 10%. But now I’m nervous. Also thinking of adding DMI and a few plant extracts. Am I too optimistic? -
Pharma said:Citric acid and the base used to counter-act the low pH are electrolytes, especially when reacting with each other . Citric acid is probably not your best choice, try lactic or hydrochloric acid and try not to play yo-yo with pH.
Why lactic or hydrochloric acid are superior to citric for pH adjustment ?
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@coco Azelaic acid is very poorly soluble in water and poorly soluble in many oils. Your product will likely turn out to be a suspension rather than a solution. On the upside, solid particles will not affect salt susceptible polymers.@HAL49 Citric acid is a triprotic acid = up to three negative charges = easier neutralisation of cationic emulsions, easier ‘cross-linking’ of positive charges, and higher salinity. These effects are also the reason why magnesium sulphate is used in w/o emulsions.
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@PhilGeis oh! Caprylyl Glycol EHG is considered weak? What’s wrong with it?
Btw: I have seen some of the manufacturer formulation with Sepinov. They used Euxyl K900 and Euxyl K903 a lot. I used both and again they considerably thinned out the emulsion. That’s 3 preservatives thinning out the emulsion at .5%. to remediate the issue I added more of the Sepinov which is not something I desired.Now on to the chelators. I assumed from my readings and research that Sodium Phytate wouldn’t be a too great choice so I opted for Tetrasodium Glutamate C. which are the only 2 I preferred using. It broke the gel miserably! (EDTA thinned it out)To my surprise, some of my actives had no effect on the polymer or emulsion, such as anything “ferment”. The glycerin extracts did ok… I guess.
I have moved on to 5% oil phase with 1% Sepinov (would you recommend increasing to avoid too much thinning out?)
Lactic Acid did not break the polymer. Thank you @Graillotion.
All and all with 1% Sepinov, my emulsion is very thin and watery.
By all means, I thought this was an easy emulsifier? People who use Sepinov intensely, please join in.
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@Pharma thank you so much for the explanation. I am finding out the hard way about Azelaic Acid. So what is you resolution for someone waiting to make a serum with this ingredient. Last time I made it, it made the emulsion unstable. Now (without adding to the emulsion) it recrystallized upon cooling. Altho I have taken measures to properly dissolve. I dissolved it in a mix of Butylene Glycol, Propanediol, DMI and water at no higher than 50 degree F. Now I’m brainstorming what to do next.
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Phytate is a polyelectrolyte, worse than citric acid (theoretical 12 negative charges!). GLDA and EDTA just carry up to four… still, if you’re encountering issues with salting out effects try using ingredients with a low amount of trace metals so you can safely use the bare minimum of a chelate. As alternatives, caprylyl hydroxymic acid might work (personally, I don’t trust that guy) and, theoretically, nordihydroguaiaretic acid might too. Depending on the ingredients and the overall preservative system, you might get away without using any chelates at all. Maybe @PhilGeis has some experience with atypical and/or nonionic/monoionic chelates?Regarding azelaic acid: if it isn’t micronised, then a suspension will easily feel sandy/grainy (and possibly irritating where there are too large crystals sitting and dissolving on the skin). Heating can speed up dissolution but you should only add as much azelaic acid as your system can dissolve at room temp (better even slightly below that), else it will always crystallise out once cooled down (because solubility of it increases with increasing temperature and vice versa). Also, recrystallisation will easily lead to even larger crystal needles than before.50°F? Are you an Inuit? Cause for all others, 50°F (=10°C) isn’t considered heating but cooling :smiley: !To my current knowledge and experience, azelaic acid can not be properly dissolved in anything acceptable at an effective concentration unless you want to go anhydrous and/or gooey/sticky. You’ll likely have to come to terms with a life full of compromises.As mentioned in another thread on salicylic acid, neutralising such an acid will render it water soluble but also utterly useless and ineffective (though you can still claim ‘contains XYZ%’).
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coco said:@PhilGeis oh! Caprylyl Glycol EHG is considered weak? What’s wrong with it?
As this forum has several certified genius PhD’s for us all to appreciate, I want to share a morsel of genius I found in my e-mail today….that is oddly fitting. I was asking this (probably Swiss) genius, about wetting agents (namely pentylene glycol) and he provided me the following explanation, which I think will help clarify Coco’s question.
The below information in Italic is not my own, but from one of my esteemed mentors:
A wetting agent is a surface-active compound, basically an emulsifier which isn’t strong enough and too water soluble to actually emulsify anything. What they do is reduce surface tension, they make water feel wetter and ‘more liquid’. This can cause viscosity loss such as observed with GMCY aka glyceryl caprylate and caprylyl glycol but it also helps to make oil droplets smaller and emulsifiers more efficient. Alcohol and soap are also good wetting agents… This means, those products make it easier for water to wetten surfaces such as your skin, water with wetting agents doesn’t pearl off but forms a thin clingy film. The liquid for your car’s windshield does basically the same, it’s a blend of methanol and/or ethylene glycol and a soap which wetten the glass and leave a fine film so the rain doesn’t give droplets all over it so you can’t see anything anymore but have the droplets ‘go flat’ and ‘flow’ all over the glass, forming a fine, transparent layer. Wetting agents also turn the surface of microbes wettable; stuff dissolved in water (such as preservatives) can actually touch the bugs and ultimately penetrate through their cell walls to finish them off.Pentylene glycol is such a wetting agent. However, the optimal alkyl chain length to not just wetten surfaces but also disrupt cell membranes for most microbes is between C6 and C14 (IIRC, the rule of thumbs is C6-8 for bacteria and >C10 for fungi) which makes hexylene glycol, caprylyl glycol, GMCY, or EHG more efficient but also more likely to interact with the emulsifiers. This being said, such highly surface active ingredients are usually only used as preservatives, not multifunctionals or emollients, at their lowest effective level to avoid interactions with the emulsifying system. Sure, you could adjust the emulsifiers but each of the alcohols, glycols and what not has its own rules which also depend on the overall composition; hence, the adjustments needed are unpredictable and require trial and error. -
A small addition to that, just to avoid a possible misconception: Viscosity loss caused by some of the above mentioned wetting agents does only apply to emulsions containing classical emulsifiers but not polymer stabilised emulsions such as those made with Sepinov EMT. If viscosity goes down the drain there, it’s highly likely caused by another mechanism.
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coco said:@PhilGeis oh! Caprylyl Glycol EHG is considered weak? What’s wrong with it?
< weak.
Please understand, safety including micro safety is an affirmative process. If you can’t defend it - you haven’t met the standard.
For preservation - design a system that should work and then confirm it passes a test. This doesn’t meet the 1st. -
@coco , if you are not aware… In the above two responses, you have tapped into two brilliant PhD’s, which have given you invaluable information. (Not talking about me!) One of them….even wrote the ‘Book’.
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I’d put my money on perpsective from Graillotion, Pharma, Perry anytime!!
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Very interesting reading! A lot made much more sense. Thank you everyone.
@Pharma thank you for providing enough info on Azelaic Acid. There was only so much I could found on the internet about it.@Graillotion can’t thank you enough. I have learnt so much from you, you probably have no idea ???? . Or you probably do since you are the kings on this page.I need to go back and recheck the whole formulation. I appreciate everyone’s input. -
coco said:Very interesting reading! A lot made much more sense. Thank you everyone.@Pharma thank you for providing enough info on Azelaic Acid. There was only so much I could found on the internet about it.@Graillotion can’t thank you enough. I have learnt so much from you, you probably have no idea ???? . Or you probably do since you are the kings on this page.I need to go back and recheck the whole formulation. I appreciate everyone’s input.
I am a mere vassal feeding on crumbs that fall from the Kings table.
I sent you a PM….. this page has an ‘Inbox’ at the top of the page…if you are not aware.
Aloha.
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BTW….just a tidbit on citric acid.
1) The reason it is so widely used….. It is incredibly cheap!
a) If you find that a single drop is making such a dramatic swing in pH…then simply water it down. If you have two ounces….then add 2 more ounces of water to it…making it 4 ounces. Then the same drop…will only move the pH half as much.2) Granted I have a VERY NARROW focus in cosmetics…but other than cost… I can find no reason to use citric over lactic….(other than the aforementioned cost), and it should be noted, that lactic is generally more mild…meaning it will take more drops of lactic, to move the pH than a comparable amount of citric. This might be a funny statement….coming from the guy who loves Triethyl citrate.
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Pharma said:Phytate is a polyelectrolyte, worse than citric acid (theoretical 12 negative charges!). GLDA and EDTA just carry up to four… still, if you’re encountering issues with salting out effects try using ingredients with a low amount of trace metals so you can safely use the bare minimum of a chelate. As alternatives, caprylyl hydroxymic acid might work (personally, I don’t trust that guy) and, theoretically, nordihydroguaiaretic acid might too. Depending on the ingredients and the overall preservative system, you might get away without using any chelates at all. Maybe @PhilGeis has some experience with atypical and/or nonionic/monoionic chelates?Regarding azelaic acid: if it isn’t micronised, then a suspension will easily feel sandy/grainy (and possibly irritating where there are too large crystals sitting and dissolving on the skin). Heating can speed up dissolution but you should only add as much azelaic acid as your system can dissolve at room temp (better even slightly below that), else it will always crystallise out once cooled down (because solubility of it increases with increasing temperature and vice versa). Also, recrystallisation will easily lead to even larger crystal needles than before.50°F? Are you an Inuit? Cause for all others, 50°F (=10°C) isn’t considered heating but cooling :smiley: !To my current knowledge and experience, azelaic acid can not be properly dissolved in anything acceptable at an effective concentration unless you want to go anhydrous and/or gooey/sticky. You’ll likely have to come to terms with a life full of compromises.As mentioned in another thread on salicylic acid, neutralising such an acid will render it water soluble but also utterly useless and ineffective (though you can still claim ‘contains XYZ%’).
Regard Azelaic acid do you think suspended particles will be effective, I tried glycols to dissolve and then add it to the cream base but always same results grainy and sandy cream
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To pharma’s excellent post - I’ve limited experience with phytic acid, esp. titrating levels. It does work. Agree re. cap hydroxamic acid - like pyrithione (ZPT - another hydroxamic acid) it might have some efficacy vs fungi but nothing for bacteria.
Chelate free systems do work - my experience in these includes ironically antidandruff ZPT products (EDTA screws up ZPT), products with some physical aspect (gels) and shampoos that added divalent cations for foam characteristic.
I try to design the best system and my bias in that is always EDTA. -
Robert said:Regard Azelaic acid do you think suspended particles will be effective, I tried glycols to dissolve and then add it to the cream base but always same results grainy and sandy cream
Skinoren, a pharmaceutical product, contains micronized azelaic acid and they showed skin resorption… a not so great one, honestly… Anyway, micronized particles do slowly dissolve on skin, then penetrate skin leaving the solvent ’empty’ and ready to dissolve some more crystals and so on. To obtain such sink conditions, the trick is to have an okayish solubility in the carrier (cream/gel) but keep it lower than solubility in skin
. Alternatively, use a solvent which penetrates skin easily but that will require the use of an excess activce and result in lots of active ingredient remaining on skin (likely the case with Skinoren). -
Pharma said:Robert said:Regard Azelaic acid do you think suspended particles will be effective, I tried glycols to dissolve and then add it to the cream base but always same results grainy and sandy cream
Skinoren, a pharmaceutical product, contains micronized azelaic acid and they showed skin resorption… a not so great one, honestly… Anyway, micronized particles do slowly dissolve on skin, then penetrate skin leaving the solvent ’empty’ and ready to dissolve some more crystals and so on. To obtain such sink conditions, the trick is to have an okayish solubility in the carrier (cream/gel) but keep it lower than solubility in skin
. Alternatively, use a solvent which penetrates skin easily but that will require the use of an excess activce and result in lots of active ingredient remaining on skin (likely the case with Skinoren).Thank you I appreciate your comment a lot, I am already using micronized pure Azailic acid from Corum, I mix 10% butylene glycol with 10% Azailic acid and disperse it in a cream base, I hope it can give reasonable effect
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PhilGeis said:To pharma’s excellent post - I’ve limited experience with phytic acid, esp. titrating levels. It does work. Agree re. cap hydroxamic acid - like pyrithione (ZPT - another hydroxamic acid) it might have some efficacy vs fungi but nothing for bacteria.
Chelate free systems do work - my experience in these includes ironically antidandruff ZPT products (EDTA screws up ZPT), products with some physical aspect (gels) and shampoos that added divalent cations for foam characteristic.
I try to design the best system and my bias in that is always EDTA.you mean even some products have zinc oxide can be interrupted by EDTA?
Also on the same issue we can not add EDTA in selenium Disulfide Antidandruff shampoo? -
@Robert I believe @PhilGeis meant only ZPT, for which EDTA would capture Zn2+ from the ZPT complex, reducing the safety of the active due to the increased absorption of PT (reducing also the bioavailability of Zn). ZnO is a crystalline compound, therefore, Zn is harder to remove from this structure.
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