chemicalmatt
Forum Replies Created
-
@garima this will not be stable without an alkali agent to saponify the stearic acid, not with that oil load anyhow. Stearic acid is your primary emulsifier there when used with an alkali such as triethanolamine, AMP or tromethamine, otherwise it is only a weak builder since cetyl alcohol is already in there. As for “mouldy”…what @Paprik said: find and add a good preservative and do it soon!
-
@Abdullah here is an interesting note to add to the excellent summation by @ketchito . The boron x-link of guar gum is used in petroleum fracking operations worldwide. When the price of crude oil rises above ~$100/barrel the fracking operation becomes financially viable and the price of ALL guars goes through the roof. I’ve seen that price increase by 5X and the MOQ go to 10,000 kg when the frackers are using it fulltime. One more reason to watch those feedstock prices! Same goes for palm oil and castor oil.
-
HI there @Graillotion Polyquaternium-37 is your best bet for rheology enhancement, i.e. my personal fave Synthalen CR from 3V Sigma USA, or the Kleasol line from Rheolab (UK). There are others, most having similar viscosity outcomes, similar sensorial haptics but differing in clarity of the gel. If a clear product is no issue then the world is your oyster. Polyquaternium-32 is second banana here, the precursor to PQ-37.
-
I agree with @PhilGeis here, EDTA is very stable. I’ve used 7 year old material before, no problem. That BHT on the other hand? It was white originally and may form nitrosamines with certain amino-functionals when decomposing like that. Toss it.
-
@LabGuy You are 100% correct, so I guess this means this post is self-correcting? You need to rebalance that polyol-water ratio closer to 3:2 of glycol: water and cut that glycerin with propylene, butylene or dipropylene glycol. That last one DPG being the best choice.
-
We’ve been through this many times before. Measure mass in a 100ml graduate cylinder to the line precisely at 60C both (liquid) product and water. Although the expansion coefficients are not same, this will NOT affect the SpG value significantly. Clean-up? Just pour out your lipstick and chase the cylinder with chloroform or methylene chloride (in a fume hood preferably.)
-
What’s with all those hyaluronate species? Must be one helluva’ hyaluronic salesperson calling on you there. You need to be more specific in your composition. Is that “PGA” polyglutamic acid? If so it is redundant with those many HA’s. What is meant by “betaine”? If it is true betaine (trimethylglycine) that may be your problem as it may be complexing with that HA crosspolymer. Remember “less is more” as Buckminster Fuller said.
-
Rapidgel EZ1 at 1.0% would do the trick and you might reduce the Olivem 300 at same time. Final viscosity would be a thin lotion more like what you are looking for.
-
There would be three intersects in that Venn diagram. E.g. PEG-40 hydrogenated castor oil is an emulsifier, surfactant and solubilizer. MOST emulsifiers are also surfactants, but not so much the reverse.
-
We use a Memmert HPC150 chamber and it works like a charm. How “economical” would be your call but Memmert makes many sizes to suit different folks. As for tests to conduct, standard accelerated stability conditions for pharma are 45C at 55% RH success over 90 days for prelim approval of a given formulation depending on its constitution (some formulations require lower temp/longer time.) Besides assay of your API - the most important test - you will also record pH, viscosity and any signs of discoloration or decomposition over the course of the shelf life and one year beyond. Testing labs? Too many to list, depends on your location.
-
This is pushing the solubility limit for azelaic acid unless you raise the pH closer to neutral with a metal hydroxide. With a little more Polawax this should work. Xanthan gum will be dispersed into water first (NOT in the oil phase) then add AZA into water at temperature, adjust pH to 5.5 - 6.5, then proceed as planned and see what you get. I would add a little cetyl alcohol to mitigate the “soaping” from the PEG ester and improve stability at same time. Kudos to you for employing Germall as preservative.
-
I think you need to more clearly define what exactly is “liquid carbomer”. There are many acrylate liquid rheology modifiers, most are 30% activity, and some are geared towards thickening surfactant systems. Others are not. If you are using one of the 30% acrylics suitable for your shampoo formula, then 1.0% w/w (0.30% solid) is far too short. Start with 3.50% and go from there. I would not adjust the pH below pH5.0 either. None of these build well below that pH and without the acid salt preservatives (as Perry remarked) you won’t need to.
-
This should work just fine. I think you may be applying too much mixing there. Slow cool while slow mix and this should build, assuming your starting temp is > 75C. Finally, adding NaCl solution while at 25 - 35 C can build viscosity here too. A little bit o’ salt goes a long way and most formulators don’t know this works with cationic systems not just anionics.
-
@ketchito is (again) on point there with DEL that propylene glycol/ADD anionic surfactant. That alone will boost viscosity and lessen the need for all that acrylic polymer. As for your Polyquat10 addition problem, disperse it into water directly 100%, then add the alkali needed to neutralize the acrylic copolymer to that mixture. Slowly add the acrylic as drop-in thickener and it will neutralize while addition goes on thereby not complexing with polyquat-10. Also, you might consider polyquat-7 or another cationic polymer with lower mass-charge.
-
@KRISTIANA Tween 80 (Polysorbate 80) is good for 5 years, if not more, especially stored in a cool dark place. disregard what the SDS or TDS say.
-
@Jorge Brenntag should be distributing all over the Iberian Peninsula. They feature BASF and SABO, two manufacturers of ceteareth-25.
-
@Heath0o7 answer is negative. If you have amodimethicone pure then no need for the surfactants. Be sure to add a low temperature since amodimethicone is reactive.
-
Check the SpG in a glass fritted density bottle at 60C or so using a water bath or microwave oven, wipe it dry quickly then weigh and record temp while doing so. Look up water density at that temp from the tables and you will have SpG. The SpG at 25C will not be significantly different as long as you reference water volume mass at same temp. I’ve used a 100ml Kimax graduate cylinder for this too. You get a value close enough to work with.
-
I cannot recommend any of those thickeners, pal. Are you opposed to using alkanolamide builders or acrylic polymers? If acrylics are not in your plan use Poyquaternium-10 at 1.0% w/w for conditioning effect, with or without silicone, and keep it simple: alpha olefin sulfonate / disodium cocoamphoacetate / then the capryl glucoside or Ninol CAA (Stepan) dimethyl amide to build viscosity.
-
The answer as @Onur states: silicone, silicone and more silicone. Nothing else beats it.
-
@Lilith The “46%N” refers to the total nitrogen content in urea itself whose molecular weight is 60. The math: (2N * 14 aw = 28) then [28 / 60] * 100 = 46.6% This is 100% urea. The 46N grade is for the farmers to understand how much nitrogen they are putting into the soil.
-
HCl would do a number on the aluminum part with lots of fumes to go with it. Fiberglass though? Only something very toxic would attack that. No comment.
-
@Tyss Vous pouvez essayer d’utiliser silylated silica pour cette formule. En Englais: utiliser “heat and high shear mixing” to incorporate. This will be translucent, not 100% clear. D’accord?
-
This has come up many times over the years. The 350cst dimethicone is the happy medium polymer chain length for hair and also skin care formula. It is not expensive either. However, I do agree with @ketchito on the amodimethicone addition here, perfect for color treated hair too. The blend with CETAC and trideceth-12 is the easiest with many clones available too.
-
This does not make sense: you want water resistance but water affinity at same time? Ok, let’s leave that one aside for now. @Onur is right in that you are using the components for a barely stable o/w emulsion, co-emulsifiers all, so it is not surprising you have an unstable invert system. Onur’s helpful additions will only work in a o/w emulsion system, so be advised there too. Bottom line: you need more study on invert emulsions my friend. Also, the usually coherent and always helpful @ketchito meant “slow” addition not “low” - a typo no doubt.