chemicalmatt
Forum Replies Created
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IT will not be a clear gel, only a suspension. Benz peroxide is slightly soluble in water and ethanol. Most trade compositions are 40% suspensions stabilized in situ, so you drop it into your batch. Shipping 100% pure benz COO is a nonstarter - one blip, spark or bump and the truck goes kaplooey!
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Go with the Polypropylene (PP) material for closures. Those are the most common and also chemically resistant. Always check samples with your primary container neck finish too: just because the spec is 24/410 for both doesn’t mean the fitment will be same especially if there is rough flashing on threads or a neck height slightly off. Valve-seal neck finish is best but trickiest to maintain quality assurance unless you get bottle & cap from same molder.
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As a RN you no doubt studied biology, so this should be easy. Get hold of any USP, the method has not changed in decades, and look up USP<51> Antimicrobial Efficacy Testing it will give you stepwise instructions. That’s the easy part. Now you need to get a hood with HEPA filter, autoclave, pourplates, petri dishes, a designated refrigerator and of course the microbes themselves, which you order right out of the catalog. VWR Scientific has all of this stuff if your are in the USA.
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Used both, but those are builders, not primary surfactants. Do not replace your APG with them, but add with to build viscosity and foam like any other alkanolamide.
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Sodium benzoate will only preserve that surfactant blend if you adjust the pH to 5.0, whereby the solubility of sarcosinate begins to lessen. I would add an amphoteric hydrotrope to make this a better mousetrap and make darn sure about that pH staying in the acid range. Might want to add tetrasodium EDTA as a chelant also unless you always wash yourself in deionized water.
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Sodium hydroxide (solution) is not a buffer, it is a strong alkali. You may adjust the product pH upwards with it, but it will not be buffered.
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Nope! That’s only one-half the USP monograph NClO activity for a wound care wash. It may dry your skin a lot, but at least it’ll be sterilized.
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Depends on the agreement, your contract manufacturer’s integrity, their skill-set and how proprietary the formula. I know this doesn’t answer your question, but in 35 years working contract manufacturing, I’ve never seen a formula provided me under a CNDA that impressed me so much I felt the need to inform our management team: “Wow, this is so novel and unique, we’d better keep this one strictly under wraps or we’ll get sued by these people!” Usually it was “..yeesh, we could have provided this brand a MUCH better formula than this mediocre thing. We’ll keep that thought and their formula confidential all the same”
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INCREASE the chelating agent as you already surmised. Tetrasodium EDTA? Double or triple it. Easiest solution is often the obvious one.
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@tecnico3vinia Your’s is a good question and worthy of an answer. In the past I’ve heated the product to 10C above its solidification point and measured using a heated pycnometer, posting the specification as 0.### @ 60C. The other means is to tare a graduate cylinder, melt the product, fill to over the 100ml mark, let cool to RT then carefully shave off excess until level at the mark. Weigh, then clean out and weigh water at the mark at RT, calculate SpG. Any discrete container can be used for this too, (i.e. a Mason jar) just be sure you mark the same volume level for water and product.
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Triethyl citrate…all day long.
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Thanks to @Pharma, @MarkBroussard and @PhilGeis for this. I have been reading about “magnesium oil” in the trade press and blogosphere for a long while and have been scratching my brain trying to figure WTF these people are talking about. Now I know! Brain freeze abated.
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@Macink You got a little redundancy there: calamine is nearly all zinc oxide, so why add more zinc oxide? To answer the question though: lots of preservatives will do this. If you have no misgivings, add diazolidinyl urea, DMDM hydantoin, methylparaben, iodopropynyl butylcarbamate…the world is your oyster depending on your location. No need to sterilize, just heat mixture above 55C and keep it there for 60 minutes, then cool and add your preservative. Dr. Phil Geis can weigh in here too.
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I’d like to add here that once you pass a certain threshold with kaolin concentration (~15%) it takes on rheology attributes that overcome all other contributors. Up to that point I’ve found that most grades work in synergy with carbomer - wierd but true - in spite of those divalent earth metals in kaolin it does not dissolve or dissociate….until it does.
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I’ll second @Fekher: that is one of the least expensive and easily obtained esters, a virtual commodity item. You’ll see it used in massage oils too for same reason.
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@Anca_Formulator, even though I am a dyed-in-the-wool carbomer/acrylics guy - there are no substitutes in my opinion - I cannot be silent here: have you tried cellulosics or just plain modified cellulose?
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Lactic acid 88% is the Standard grade supplied by industrial firms. The solid and 80% you only see in lab source catalogs. This is why Evonik used that assay. My own experience has been 3.5 SPDA : 1.0 LA 88% resulting in pH 5.0 the sweet spot for emulsion stability. If you are also adding alkyl quats - and most hair conditioners will - that pH drops down to 3.5 - 4.5. That’s OK too.
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Duly noted Dr. Phil! I’ll bet you could do a webinar on this topic - what RIPT studies intend, etc., etc.
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@Fekher Synthalen W600 can work with LESS surfactant more readily than with MORE surfactant, as may Aqua SF-1. Only diff is W600 costs much less.
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You guys are off by a factor of 10. Its $2000 monthly for a 6-month starter, even less for an annual subscription. The Clean Beauty peeps should find it most useful as it conveys and checks against all those greenie-groups’ sanctions. Wouldn’t want to piss off Gwynn Paltrow with your emulsifier now would you?
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Just plain old ammonium carbonate. Add amorphous silica to keep from agglomerating. Cheap stuff.
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Nope, you plug in your formula like an Excel sheet and the software scheme tells you if an ingredient is allowed in that nation, or beyond CIR allowable limits or disrespected by Sephora, goop, Target, Whole Paycheck, etc. It makes no judgements, only checks against all nations’ laws and all those retailer ingredient sanctions. All at same time and updated monthly.
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What @Perry said, but I suspect you may still need a rheology stabilizer in there anyway with that APG. Try hydroxymethylcellulose or polyaquaternium-10 or an acrylate copolymer. Also, Olivem 300 is redundant with PEG-7 glyceryl cocoate as a refatting agent. Choose one or the other and save some coin.
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@PhilGeis @Perry @Anca_Formulator, I’ll extend my thanks to Phil here too, but I have to add I saw a demo of the Good Face Project software while at Cosmoprof North America last week and it impressed the heck out of me. Check it out at http://www.thegoodfaceproject.com
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@vitalys thanks for all these links. You are a generous soul and tribute to the science of personal care.