chemicalmatt
Forum Replies Created
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Though philosophically I’m with Bob Zonis on the subject, here are some cues I’ve experienced. Liposomes (phospholipid vesicles you can make with lecithin) are designed to penetrate the stratum corneum while carrying a “payload” of vitamin E or whatever lipid can fit within. Emu oil (kalaya oil in some parts) has pronounced penetrating properties and has even been known to cross the blood-brain barrier. Ethoxydiglycol has the property of enhancing penetration of the hair cuticle inot the cortex with small molecule components (e.g. NaOH, LiOH). Unfortunately, it also halps penetrate the scalp with those same alkali - ouch! Then there is that isosorbide ester ICI (now Croda) has that allows triglyceride oils to penetrate into the subcutaneous layer. I forgot its name.
(Hey Perry, now that the glaciers have receded from North Avenue here in Chicago, start joggling again, clear your brain with fresh air, and come up with an article about this topic.)
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Gustavo, ozokerite is part of the petrochemical (mostly) linear alkyl homolog family of petrolatum/microcrystalline wax/ozokerite/paraffin. It is very useful in thickening and stabilizing mineral oil, petrolatum based emulsions, even the water-in-oil ones, and can harden those cyclomethicone-stearyl alcohol antiperspirant sticks like nothing else ( I’m talking 0.10%!). The others are natural waxes, more polar, complex and vary softeness and pliability in lipsticks, lipbalms, color make-up pencils. I never tried burning some to see what happens. Could be a renewable fuel! Perhaps another forum member more versed in color cosmetics can help here.
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Makes sense, Mike. I thought Stepan made this creature, Even better might be the Pationic lactylate surfactants from R.I,T.A., which work well as primary emulsifiers, though the R.I.T.A. literature strangely doesn’t mention that. Pationic SSL is what I remember using (stearoyl lactylate). I can also tell you I remember an article years ago noting that lactic acid and its salts actually stabilize urea from hydrolytic decomposition, so you are probably in good shape here. The old 10% Urea skin-care creams used that trick.
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No experience necessary, love. As a rule, the higher carbon-chain analogs are milder. So, coco-glucoside will be milder than lauryl glucoside, milder than decyl glucoside, etc. Sodium Cocoamphoacetate is a good mild amphoteric used extensively in hair-care. Sodium cocoyl glutamate also very mild and a good foamer. You are better off, if you can, to purchase these separately and save some money. Not sure what “SMC Taurate paste” is, but sounds expensive if it is a taurate salt. Leave the glycerin out. It kills viscosity, hinders foam and doesn’t do anything in a system such as yours.
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Actually, Bob, it appears Dave’s got Arlacel 165 in there too - the old PEG ester workhorse. That being said, you may want to convert this to an ether alcohol system and get away from the esters altogether. The Steareth-2/Steareeth-21 combo usually works. ( I just use Steaereth-12 and split the proverbial HLB difference.) Hydroquinone is far more electoryltic than folks remember, and that metabisulfite is a contributor too.
I’ll pose another issue for you here, or open another thread: have you tried assaying this on HPLC with a UV detector yet? I recall having to resolve the two enatiomeric forms of hydroquinone by varying the mobile phase polarity program. It was a bitch! Wish I still had that test method, I’d email it to you.
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Mike, have you considered the use of sodium lactoyl lactate? This is an entriely different animal, so to speak, with entirely more powerful emulsifying properties than “sodium lactate”.
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Yes to both of the above.
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Perry, if your first point happens, and I’d have more than a little shadenfreude if it does, wouldn’t it be ironic if the public became alarmed over the LACK of preservation in cosmetics due to the continuing scares over alleged preservative toxicity? Might we finally see The Backlash?
Bob & Perry both have a point about the fate of Avon. That ship is going down, one way or another.
And,Mike, I can agree with Perry. Here in the Land of the Fee, we can still go bankrupt simply by getting ill.
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Mike, not only silica, but good ‘ol pumice - the original exfoliant, if you will - is cheap and safe for the environment. The stuff comes out of volcanoes. The nut-shell flour abraders for scrubs are fine, but have always been inexcusably expensive too. No supplier has ever been able to convince me why scrub flours made from almond shells, apricot shells, walnut shells - all of which are food by-products unsuitable for consumption - need to cost so much just because the supplier milled them through a Fitzmill, then irradiated them, when their starting material was obviously cheap to begin with. In the past, I’ve been tempted to buy a cheap, used Fitzmill and make the stuff myself!
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Naturalista, not all Polyquaterniums have styling ability. Most do not. There are so many, too. Ayla gave you a great first step, since ISP (now Ashland) came out with one of the first: Polyquaternum-11 (Gafquat). I’ll recommend Styleze W-17 terpolymer from that same manufacturer. By the way, here’s some trivia: the GAF in Gafquat is from GAF Corporation, more famous for their recording tape, which bought the technology from the Antar Corporation, then sold to ISP. All of which probably ocurred before you were born. THAT’S how long Polyquaternium-11 has been used in styling products.
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Can anyone say “supersaturation”? Your product, settled, cooled crystallized. This is Physical Chemistry 101. You’ll need a co-solvent, dude. I advise ethoxtdiglycol or propylene glycol. Check the Merck Index for solubitlity parameters.
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Merit, there’s absolutely no good reason to have ethanol in that formula, assuming SDA is what they are referring to. Unless you smell it in there, sonsider it one of the many typos we see in INCI abel listings. I would disregard it.
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Copy that, Mike. Just today I read this week’s issue of C&E News (17-FEB-14) and learned about the nefarious WERCS program being commanded by the likes of Walmart and Target stores. This was curated by the Environmental Defense Fund. When will they stop with the fear mongering?
F.Y.I., my favorite danger chemical (HEALTH:3, FLAMMABILITY:3) is a dry gin martini!
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Simona, most bar soaps are mildly alkaline, as you’ve noted. These do not raise the “acid mantle” of the dermis all that much. No need for strongly acidic post-treatment. Most standard skin-care lotions have a pH in the 6.0 - 7.0 range, and should suffice. Also, those “people claiming” this condition are not chemists. Most syndet bar soaps are much milder on the skin than the old harsh coco-alkali ones, and lots of glycerin and olive oil (“Castille”)soapers are in business today as well. As always, use empirical knowledge: billions of people have used bar soaps for over a hundred years. Have the complaints registered in the thousands? millions? I rest my case.
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Sodium sulfate wouldn’t do much Zink. Sodium sulf ITE, on the other hand is keratolytic, yet I don’t think that applies either (decomposes to H2S, sewer gas, poisinous, yadayadayada). You are probably seeking flowers of sulfur, which is sometimes called sulfur florets or colloidal sulfur. Dispersing in oil works best, as it is not water-soluble, not much anyway. This is an old school acne remedy. Old as in 1950’s old.
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Cosmo, if memory serves, DHA undergoes slow acid-catalyzed hydrolysis to glycolic acid, whereupon you get the extra protons that lower pH. The more water you have in your formula, the likelier this will happen. Perhaps cut it with some propylene glycol. I’m unsure whether a buffer would help, but you may try a glycolic/glycolate buffer system at pH 4.2 and check it out.
There have been many odor blockers over the years, the most common being the lactones. These work in water-based systems. ICI (oops, I mean Croda) might still offer Forestall, which is an alkyl quat that used to work well masking thiogylcolate odors in permanent waves. Other than that, your first guess is probably true: more fragrance, more better.
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Shah,
I’ll second David’s comment. We don’t mind giving advice here, that’s an altruistic pursuit. But to shell out a working formula is asking for a lot. Shahbaz has already supplied you with a LOT of helpful information; you can take it from there.
Note to Shabaz: SLS vs. Thioglycolic acid in the Skin Irritation Contest, Thio always wins! Nobody will notice the SLS while their skin is being dissolved by the thio along with their hair.
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Mike, I’ll offer up C12- 15 Alkyl Benzoate (Finsolv TN). As I am fond of saying: what CAN’T it do? Among other things it serves as “Poor Man’s phenyl trimethicone”, since it gives 70% of the shine at one-fourth the cost as your fave, also stabilizes SPF, and is completely miscible with cyclomethicone. It can de-grease petrolatum or beeswax and de-oil mineral oil or any other.
Also in “ester-land” is octyl isononanoate, as versatile a workhorse ester as you’ll find, and one that many suppliers offer now that it’s secret powers have been established.
In the preservation area: p-chloro m-xylenol (PCMX). It has limitations in solubility and odor, but it works great even at 0.10%, at any pH, especially with phenoxyethanol, and is approved virtually everywhere. Originally listed in the British Pharmocopaeia if memory serves, where it was first used to sanitize latrines during WWI. “Poor Man’s triclosan” if you will, with none of the bad press.
(This is a good idea by the way.)
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Compounder, when you lowered the pH, then added salt, you salted out the saponified coconut/palm higher fractions (C18 +). Leave the pH at 9.0 plus, and don’t add salt. As long as your total solids are less than 25%, you should be OK. If not, just decant the water off and re-tag it as shaving cream. No problemo!
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Dandy,
With an oil load of 25 - 30%, you could get away with formulating without any GMS or cetyl, which by the way will not work here without a co-emulsifier of higher HLB (that’s why so many supply the glyceryl stearate and PEG-150 searate combo), and just use Pemulen TR-2 polymeric emulsifier along with your Carbopol. No other emulsifer needed - just watch your electrolytes!
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Avick, if you are talking about oxidative (“permanent”) hair colorants, then film formers and UV absorbers are the best bet. I’m a big fan of deacetylated chitosan as a natural film-former. It’s cationic, grants a soft feel, doesn’t have much of a build-up attitude and might work OK here. (It still won’t work as well as the best of the synthetics: polyethyleneimine.) And no, I do not sell chitosan, so my opinion is neutrally informed. As for natural UV absorbers - uhhh…coconut oil has a SPF 2, I think. Not much help there I suspect.
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Didn’t DOW invent the Chelation Value spec? Or was it Hampshire? Trivia question only.
Beha, it should be noted Mike is referring to solid state EDTA sodium salts. Some folks like to use the solutions. Calculate accordingly if you are one of them.
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I seem to recall it also dissolves in other polyols, such as glycerin, sorbitol, ethoxydiglycol, dipropylene glycol. Cannot remember the solubilty factors, sorry to say. Best yet is ethanol or phenoxyethanol - if you can stomach it. I also recall certain amphoterics like coco-betaine worked. Hope this helps.
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gfeldman, you are correct. You want to enhance, not inhibit, the activity of peroxidase enzymes, Gustavo. As for antioxidants in skin-care formulations, there is a virtual galaxy of them out there. I wouldn’t know where to start there are so many..
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I’ll just point out here, Jose, that 15% salicylic acid is wart remover country. Just how much “beta-hydroxyacid” do you think you need? You may want to pull back a bit.