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Lake pigments settling in “lip gloss” formulation (photos)
Hi all!
I am trying to formulate a tinted “lip oil” which is essentially a type of lip gloss that is runnier. To give you an idea, a product example that is available in the market is Clarins Lip Comfort Oil.
The problem I’m facing is the lake pigments in the formula tend to settle out at the bottom after a while. Now I also notice some pigment settling in the commercial product (Clarins Lip Comfort Oil) but not as much as mine. I guess some pigment settling is normal in this kind of formulation since the end product is more fluid than a typical lip gloss but I’m wondering if there’s anything I can do to minimize it? I’m already using pre-dispersed lake pigments in castor oil and my formulation is actually less runny & slightly less pigmented than the commercial product.
Below is the formula that I’m currently working with.
43% Versagel ME 750
25% Polybutene 1300
7.5% Diisostearyl Malate
8% Tridecyl Trimellitate
5% C12-15 Alkyl Benzoate
2.8% Pre-dispersed Lake Pigments (in castor oil)
2% Sweet Almond Oil
1.5% Jojoba Oil
1% Cherry Kernel Oil
1% Tocopheryl Acetate
0.7% Fragrance
0.5% PhenoxyethanolWould mixing with an overhead stirrer help? Or would a homogenizer help?
Also, would 0.5% Phenoxyethanol provide enough protection in this anhydrous formulation?
Your help would be greatly appreciated. Thank you in advance!
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12 Replies
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Bump. Has anyone got any idea?
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@sweetflakes Not knowing much about these type of products, I suspect the stucture of your product doesn’t provide enough resistance for your pigment particles, so they just go to the bottom. Perhaps you could add some polymeric material (better if crosslinked) to provide some support.
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You need threeroller mixing machine for your pigment to ensure distribution, and don’t forget to add some settling prevention like hidrophobic silica fumes ( aerosil 876 cmiiw)
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Not to add a plug but you could try our D&C Red 7 Lake, they are micronized for easy disperse. http://www.rkpigments.com
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Hi @ketchito & @ariepfadli, you’re absolutely right. I tried adding a little bit of silica dimethyl silylate and it keeps the pigments from settling. I had no previous experience with silica dimethyl silylate though so it wasn’t a smooth dispersion. What’s the correct way to disperse it in oil? Do I need a rotor/stator homogenizer or would a 4-bladed overhead mixer suffice?
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I would recommend switching to a micronized pigment, like @RKPigments mentioned, and thickening a bit to make sure they remain suspended in the gel matrix.
There are also GREAT lip bases out there. Sometimes formulating from scratch isnt worth it. They can be customized easily and make speed-to-market a breeze.
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@KMRCSMiami thank you for taking the time to respond. Adding silica dimethyl silylate actually worked to suspend the pigments. I’m just having trouble dispersing the silica completely. Any advice?
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sweetflakes said:Hi @ketchito & @ariepfadli, you’re absolutely right. I tried adding a little bit of silica dimethyl silylate and it keeps the pigments from settling. I had no previous experience with silica dimethyl silylate though so it wasn’t a smooth dispersion. What’s the correct way to disperse it in oil? Do I need a rotor/stator homogenizer or would a 4-bladed overhead mixer suffice?
You can use an overhead mixer, but get a dispersion blade for it (which is also called a Cowles blade). They’re very simple to manufacture, so grabbing a cheap one ebay for your overhead is fine.
I would recommend batch sizes greater than 400 g and 1500-2000 RPM when using it.
For reference: https://fusionfluid.com/products/mixing-impellers/cowles-disperser-multi-blade-stx
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Thank you so much @RobboAU! I’m currently waiting for my dispersion blade to arrive in the mail. Can’t wait to give it another try.
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You’re welcome, hope it helps. Keep in mind that whilst this is helpful for lab-size batches, scaling it up beyond the 1 kg range can be challenging and expensive.
Let us know how it goes!
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@sweetflakes, to add to @RobboAU advisement, which is a great idea regarding that Cowles blade, you need to really beat on the silica for a long time in nothing but the first 5 items here. Do not add the pigments and other materials until that has mixed a good two hours at top speed. You should observe the batch start to thicken a little. Mix until it thickens no more at least to your eyes, then add your pigment blend and beat on it another 60 minutes. Finally add the rest. Silicas work great as anhydrous rheology aids but the issue is you cannot always tell when they are fully dispersed. Only time & kinetic energy can assure the outcome in yield value. This depends on the oil blend too. (Never tried this with Versagels before.) Also, phenoxyethanol isn’t needed. No water - no worries.
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Hi @chemicalmatt. Thanks a bunch for your advice! I really appreciate you taking the time to share your insights with me. I have noted everything in my notebook. I will share the outcome later
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