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Oxidation of mineral makeup
Hi,
I am formulating a cc (color correction) cream using iron oxides as my color pigments and Titanium dioxide. The rest of the ingredients in the cream are pretty standard: various oils, beeswax, glycine betaine, shea butter, hydrogenated palm glycerides, allantion, coco-caprylate, emulsifier, preservative system with Dermasoft ECO, fragrance. I get a nice coverage, slip, and skin tone correction, but when the product is applied to the skin, the color somewhat darkens after 15-20 minutes. My understanding is that it is due to the further oxidation of iron oxides. Am I right? Is there a way to prevent/reduce that effect, or it is something unavoidable in mineral makeup? -
6 Replies
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https://chemistscorner.com/cosmeticsciencetalk/discussion/comment/9162/#Comment_9162
These are few observations and comments made by @Bobzchemist, I think he has explained in the best possible manner for all and sundry. -
This is a textbook example of iron oxide pigments not being de-agglomerated/milled enough.
Applying makeup to skin actually exerts a tremendous shear force on the product. If your pigments have not been de-agglomerated enough, when they are applied to skin, the shear force will de-agglomerate them, making the color on skin darker.You can reduce/eliminate this effect by doing one or more of the following:1) Milling/grinding/dispersing your pigments for a longer time/more intensely, so that they are down to their primary particle size, eliminating all agglomerates.2) Adding a chemical dispersant, so that your existing process is capable of taking pigments down to their primary particle size, eliminating all agglomerates.3) Adding particulate ingredients to your formula that will prevent the dispersed pigments from re-agglomerating. -
Greetings, all.. Been running into the same situation (to a certain extent) here in my home formulating workshop..
“2) Adding a chemical dispersant..”
Would you please offer a few suggestions? I say a few because as a home formulator, creating for personal use only, my access is restricted to commerical sites that deal with the general public.. (Bigger named distributors want nothing to do with me and believe me, I have asked.. Without a sales base and website, I get no further responses.. Sadly..)
“3) Adding particulate ingredients…”
Again, would you please suggest a few..
Also, I am grinding approx 1.6% yellow oxide, 0.4% red oxide w/blue undertone, 0.3% manganese violet, and 0.05 to 0.15% brown oxide with 14% ti02 to get my color concentrate and it matches my skin tone well.. I have the Fitzpatrick’s I light skin that always burns and the lightest shades of Hourglass, Nars, Clinique, and the newer Laura Mercier incarnation (and many other department store brands of foundation makeup) look so yellow on me..Oompa Loompa, if you follow my meaning, is the effect on my skin..
But I digress..
I have tried mixing the individual oxides with isoeicosane, then combining them at the relative percentages.. This worked well except there was a white film on top of the finished concentrate.. Tried Alkyl Benzyl Esters in the same fashion, but once in formulation with emulsifier and fatty alcohol, thickeners, etc. It clumped up into what I can only liken to curds of cottage cheese-like masses in a soup of beige colored oils..
It’s so sad.. I hate wasting ingredients.. And I have been wanting to post here for quite some time. I apologize in advance for the excessively long message and thank you all for reading and responding..
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For home formulating, first get a glass muller and frosted/etched glass plate to grind your pigments into oils on, then you also need an Osterizer and a mini-container for dry blending. (You can use other blenders, but they don’t work quite as well)
Isoeicosane (Permethyl 102A) is a fine ingredient to work with. What you’re seeing is titanium dioxide flotation, which may go away if you grind better.The websites makingcosmetics.com and pvsoap.com should give you most of what you need otherwise.If I were doing this, I’d try to add a pigment mix to an existing makeup, or buy a pre-made base, rather than try to formulate from scratch. Why re-invent the wheel?What physical form of makeup are you trying to formulate?The rest of the info you’re asking for, I’m afraid, crosses the line into things you’d have to pay a consultant to find out, if you didn’t want to do the research on your own. -
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First, thank you for your swift response.. and apologies for my delinquent reply..Glass Muller: brilliant..! i had to purchase a rather small one, but its leaps and bounds above the iteration of doom inherent in the curvature of the mortar and pestle’s design.. (aka: relentless “grind-grind-grind-slurry-oh no, its all on the sides” and 8 utensils later im still unable to (hygienically) get said slurry OFF said tools/mortar, back into the center where, again, i grind-grind-grind-oh look, its up on the sides again.. *face-palm*) neophyte color cosmetics formulators know precisely this iteration of doom i mentioned here..back to the muller: i have a large, smooth glass cutting board (dedicated to muller-ing), would this glass be sufficient? it is 16″ x 12″ x 1/4″ deep, approx.. the muller works well on it; there’s this awesome ‘suction effect’ that pulverizes the color quickly.. i am having difficulty getting the slurry off of the glass “plate”.. tilt-scrape-gather seems so inefficient.. (99% isopropyl alcohol, stearamine tablets, and something called ‘c brite’ are all employed in my workshop and on all utensils.. scrape and gather is not as unsanitary as it sounds!)and as far as the osterizer, (which i believe is in the mailroom.. i ordered one but am content to use my hitachi drill with jiffy mixer attachments for all other applications.. have to go pick it up..) you suggest i blend the dry pigments in there prior to the muller? my color concentrate formula is in three parts:a red component consisting of: 0.3 ultramarine pink 0.3 maganese violet 0.4 red with blue undertone 0.5 magnesium stearate 1.0 zinc oxidea yellow component consisting of: 0.5 yellow oxide 0.1-0.2 brown oxide 0.3-0.4 matte serecite 1.0 zinc oxide and 0.5 hdi/vinyl dimethicone crosspolymerand 10 g of a white base, containing at least 5 g Ti02 0.5 nylon 12 1.0 boron nitride 1.0 mica spheres 0.5 silica/vinyl dimethicone crosspolymer 2.0 serecite mica (etc)blending each component individually is not a problem, but would the osterizer ruin mica spheres, boron nitride (which i believe has a hexagonal shape), etc? i do not use any sparkly micas.. hate those, grr..those blender cups: i have been looking everywhere for (well, obviously not..) thank you! are you suggesting that an auxiliary blade apparatus is required for those small blending cups, or that the auxiliary blades are generally recommended for pigment blending in said cups/blender?your time and attention and expertise and patience are greatly appreciated and valued.. thanks so much for reading, responding, (and not judging)..
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