Bobzchemist
Forum Replies Created
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It could be microbial contamination. What was the final pH? Have you run a plate count?
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I think it would be useful to go over the options for making/selling cosmetics to consumers.
Listed from least amount of effort to most:1) Buying generic products wholesale and selling them retail.2) Buying a private label product and putting your name on it3) Having a contract manufacturer make a stock/library product and fill it into a stock container4) Having a contract manufacturer make a custom product and fill it into a stock container5) Having a contract manufacturer make a custom product and fill it into a custom container6) Doing some or all of it (R&D, testing, manufacturing, filling, packaging) yourselfHave I missed anything? -
In order to have a colloidal dispersion, and not just a suspension, you will need to have all particles below 1 micron in size. The Grant dispersion will work for this.
However, in addition to having the zinc oxide stable within the dispersion, you are also going to need to make the dispersion stable as the oil phase of a low viscosity emulsion. This is not a trivial/easy to solve problem. If I were given this as a project, I would estimate at least six months of full-time research to get a stable low-viscosity formula.You’re going to need some heavy-duty emulsifiers at significant levels, in my opinion. Sclerotium gum won’t cut it. One of the Pemulens might work, but I don’t think you’ll be happy with the viscosity. Try it, see what happens. -
Can you use Laponite?
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You need to talk to @Duncan. Are you on LinkedIn?
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To have a stable colloidal product you’ll need to have the zinc oxide particles at colloid-forming sizes, otherwise gravity works.
Are you going to use a pre-made dispersion, or a colloid mill? -
In the UK,I’m pretty sure the EU regulations have effectively made it unlikely to be able to make and sell small quantities at a profit. £1,800 sounds like a good deal.
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Going the private label route can be significantly cheaper, depending on the volume. It all depends on what you’re trying to sell and why.
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stabilize the W/O. By itself, lanolin can carry a few percent of water.
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@lotachi, please start a new discussion if you have a question.
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Use Veegum Plus “Typical use levels are between 0.5% and 3%.”
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Use a muller(cheapest) a ball mill, or a 3-roll mill(most expensive) Mortar and pestle will not work.
use this to judge fineness: http://www.gardco.com/pages/dispersion/fg/SSgrindgage.cfm 4 Hegman or higher, 2 mil/50 micron particle size or lower = no gritty feeltalc/mica are exceptions due to platy particles. -
Ultra-fine milling in a viscous base is important, or the lip feel will be gritty.
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I’d suspect that too. Have you tried anything like Dry-Flo? Is there room for ethanol in the formula?
You might also want to think about an alternate thickener. -
@Avick Amanda, you are not alone in your Whole Foods formulation dilemma. Several of us have been extremely frustrated by their arbitrary decisions.
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If it’s that hard to assay the Vitamin C, how could it possibly have any effect on skin?
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PTFE (Teflon) or glass-lined equipment and storage containers.
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@ChemWizard, The easiest way is to try it for yourself, or look at the ingredient labels of the various products that are already on the market.
Thinking back to the few classes I’ve had on pharmacology, I will also point out that solubilizing active ingredients isn’t always the best method for incorporating them into a preparation. Sometimes, you get more effective activity by using partially soluble or even insoluble active ingredients. -
Many color cosmetics use Veegum HV/ PRO(Magnesium Aluminum Silicate) either by itself or in a synergistic mixture with CMC (Carboxy Methyl Cellulose) or Xanthan gum.
You could look at Laponite, as well.I’d also suggest a combination of Pemulen and Carbopol, if you need a lighter feel on skin.