[chemicalmatt]

Belassi, I didn’t know glycerrizhic acid was keratolytic.  Or is it the ammonium salt that is? Wonder what the activity is relative to thiols? I’ll be interested in your results.

[chemicalmatt]

As so often the case, the answer is: it depends.  Only you know the colloidal and rheological properties of your ingredient formulation YQ1, so you will need to determine the sheer-stress allowance.  Just shooting from the hip here (and I am a Silverson guy), if this pup is rolling at 1750 rpm, which is standard, and is a fixed (in-tank not in-line) device, use the 4blade + rotor with the normal slot stator for general use. Keep the stator static, change the rotor to achieve better results, starting with the 6 blade then the toothed, which is useful for chunkier solids like kaolin.

[chemicalmatt]

What Bill said - plus, BrO3- will not go to its highest oxidation state readily, since IT is being reduced.  I suggest concentrating on your concentration carefully with this system.  Any excess bromate can cause drying, shedding and damage to the just-relaxed hair, so keep it to a minimum. Its only a little better than peroxide, not a lot.

[chemicalmatt]

Quats work best with cyclomethicone and virtually all other silicones. Try behenyl quats first, and you don’t need much. 

[chemicalmatt]

Great idea, Belassi!

[chemicalmatt]

I would break out Functional from Aesthetic, as laskedbetter describes, too.  Within that subcategory would be “Rheology modifiers”, and even “Flow modifiers” (not the same as “thickeners” where tribology is concerned). Within Aesthetic, I would add the sub-category “Sensory modifiers” i.e. skin sensation modifiers, as many esters and starches will do for the product. I only perused this briefly. I’m sure if I study it more the more I’ll find, but that may be overthinking it too. Cool, Perry.

[chemicalmatt]

I just spent over an hour on the EWG site looking up “rated” ingredients to satisfy a client’s requirements.  Now I want to puke. I mean it, I really want to hurl chunks after reading all the crap that organization is serving up.

[chemicalmatt]

The former Scher Chemical Company, founded by Stephen Scher, once had the best array of esters in the marketplace - those Schercomols you mention. They are now part of the Noveon - Lubrizol empire. Picking a favorite would be very hard. Depends on application and play-time. My go-to all-around workhorse ester is isononyl isononanoate, which I believe Lubrizol (Scher) offers. Side-note: Scher also had some very unique quats, as I recall. Check those out if you have the time.

[chemicalmatt]

IF your mouthwash has 13% or more ethanol, (SDA 38C if memory serves is the one with thymol and spearmint suitable for dentrifices), then you don’t need to worry about a preservative all. Likewise, if your “gum gel” has lidocaine HCl and oxiquinoline sulfate or pramoxine HCl as the old-school ones had, no preservative needed either.

[chemicalmatt]

Anna, none of the esters mentioned will reduce the “soaping” effect you observed - not by much anyway. Olivem 1000 lends just a little, but the EGDS you’ve added to your formula, or another stearate or laurate ester, is the likely culprit. Solution is quite simple: add cetyl alcohol, even 0.50% can cut down that soaping effect dramatically. Kudos for using my favorite ester C12-15 Alkyl Benzoate in your product.  As I’ve said on this blog before: what can’t Finsolv TN do?

[chemicalmatt]

I’ll offer this Nasrins: for quick determination of emulsion or liquid product integrity, Mark’s centrifuge test is more than adequate.  Actually running that test at a sample temperature of 50C is downright brutal - if it passes you can be 99.9% sure your product will not separate or “cream” for several years! Running it at RT is good enough.  What you will not determine, however, is the product’s stability as it relates to other attributes and variables such as pH, viscosity, scent deterioration, general appearance, color fastness, etc. Only a full 90-day accelerated test as described in the IFSCC monograph Bill Toge mentions will give you that.

[chemicalmatt]

Grip, you’re not going to like this:  the answer to your issue is none of the above.  All of those acrylate polymers, even the much vaunted Aqua SF-1 are electrolyte intolerant  - at the level you are working with, anyway. With a straight-up, low/no water soap system based on earth alkalis, your best bet is keep on with the colloids. I’d investigate Veegum, laponite, or good old bentonite even. You also have the disadvantage of using the scrub with the highest bulk density known: pumice.  That’s suspending rock, dude. Your soap may not look as pretty with the bentonite holding up your pumice, but then pumice ‘aint so pretty either, am I right? Then again, without much water to work with, I’m unsure you’ll be getting anywhere with anything. Good luck.

[chemicalmatt]

Bri, the author appears to be making a broad, somewhat pedantic statement about the incompatibility of benzoic acid with nonionics. They also state that caveat for other preservatives as well. They are not versed well in the science and the art of preservation. Lesson here: don’t believe everything you read, or at least apply critical thinking to it. They are likely referring to the deactivation of certain preservatives by TWEEN 60 and TWEEN 80. That applies to parabens, and somewhat to phenolics, but shouldn’t be deemed the same pathway for other preservatives, and certainly not other nonionic surfactant chemistries. Use PEG ethers and you won’t go wrong. As for quats, if you are talking straight alkyl/benzyl quat surfactants, such as CETAC, StearAC, etc., you might want to use something else than benzoic acid, and not much of it, since those compounds offer more antibacterial and antifungal activity than most realize. “Honeyquat”: they still make that crap??

[chemicalmatt]

Using straight coconut fatty acids with a very small amount of extra stearic, then saponifying at 80C, in order, with TEA, KOH and NaOH usually produces the best results. You’ll see on labels lauric, myristic, palmitic acids: those, along with stearic, comprise 85% of the coconut FA fraction.  You will get dramatically different physical state and foam state outcomes using TEA vs. NaOH vs. KOH alone, that’s why a combo of alkali are used, and order of addition important. Expect the product firmness and appearance to change over the first six months. The old Noxema - Calcium (oil soap) and Ammonia (water soluble) with stearic/palmitic used there - would gain a golden soft pearlescence after 4 - 5 years. With TEA now in decline, I’ve been wondering what the shave cream people are doing these days. TEA gives you the lush, pearlescent foam most consumers expect. Perhaps they are revisiting ammonia?

[chemicalmatt]

There are many, many more fragrance components stable in ammonia than there are stable in sodium hypochlorite, a stong oxidizer. You really need to run this by your fragrance supplier, else you will be at it a long time.

[chemicalmatt]

I’ve never used it, so I couldn’t say. Look into the Noveon urethane fixatives (now Lubrizol) for starters.

[chemicalmatt]

To Sarah: I realize you do have a full brain, so please excuse my ratty comment in the original post.  That you’ve used that Lonza Biovert with no difficulty is as much a testament to your good GMP as it is to your preservative selection.  I’ve read Lonza’s literature and I find it underwhelming. That product relies on redox processes, and it’s activity can be imperiled by so many ingredients, including ones mentioned or alluded to by Making and Mark. Regarding Mark’s comment,Sarah, have the results of your USP Preservative Challenge been acceptable, and did you retry that challenge on the same lot 12 months later? I’d be curious.

To all: thanks for the feedback.  You all make a compelling argument that a holistic approach to formulating must be employed when using any preservative that does not use blunt cell-disruption chemistry, like my friends the parabens, phenolics and formaldehyde donors do Regarding point #11 in Making’s exhaustive list: Dave Steinberg once said the best preservative of all is strict GMP.

There’s enough material here to draft an interesting article in C&T or SPC.  Anyone game?

[chemicalmatt]

…and I know what you’re already thinking: yes, they do stain one’s clothing. Big time.

[chemicalmatt]

You betcha’ there is. Have you considered the polyurethanes? 

[chemicalmatt]

Mark, I think those crystal sticks are just aluminum chloride, plus some Epsom salt, other stuff.  The “ammonium” tag is a red herring. Further evidence of the paucity of integrity among so many in the natural product industries. Just look at the price points: I rest my case.

[chemicalmatt]

Pepe, since this sounds like a typical alkali saponification formula, limit your emollient additives to the water phase. I’d suggest Polyquaternium-7, another acrylamide copolymer (see Merquats),  PEG-12 Dimethicone, PPG-5 Ceteth-20 (Ele’ Corporation’s - NOT Croda’s); all compatible with the anionic system to some degree. These will lend the slip without affecting the soap.

[chemicalmatt]

Thanks for the lead-in, milliachemist. It’s good to take a break from Ebola combat today.

To address nasrins’ immediate problem, perhaps she only needs to alter her order of addition.  If she has 15% total solids surfactant activity in her formula, the norm for a baby washer, and we assume most of that is amphoteric, also the norm for those products, then she likely has what she needs to clarify her formula.  She needs to incorporate the fragrance oil directly into the surfactant blend, then add to water (or water to it, as the case may be) and other ingredients. As for the viscosity crash: I suspect a big slug of nonylphenol ethoxylate is lurking in her fragrance. That surfactant is commonly used as a fragrance oil ingredient (disperser-soulbilizer) and is a notorious viscosity crasher in anionic-amphoteric systems. Bummer.  Nasrins, you may need another builder in there, or a rheology modifier (Methocel works). 

[chemicalmatt]

Hey Belassi:  thanks for all this background information. In this age of rampant MERS, perhaps TTO (melaleuca alternifolia) can make a comeback in the homeopathic realm as a topical germ killer.  xenon126, for the record, thymol, the active extract from thyme (oil), is a substituted phenol used for many decades (see Listerine.) Furthermore, perhaps your discussion may have originated when you may have seen lactic acid listed in an ingredient dec.  Be advised it was only there as an acidulant, not an antibacti device.

[chemicalmatt]

Nadia, you refer to hair swatches, not switches, for testing purposes no doubt.  All types can be procured at Jos. Lowenstein & Sons of Brooklyn, NYC., the venerable source for hair swatches and dyes.

[chemicalmatt]

Belassi, contact Siltech directly for their line of water-dispersible alkyl modified silicones - and save a lot of money.  That price sounds WAY too high. Should be more like $15 - $20/ kg. Stay off of Lubrizol’s analogs too, they are over-priced compared to Siltech’s. Siltech rocks!