Bill_Toge
Forum Replies Created
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@Danedane that depends largely on what else is in your product, and how sterile the clay is
also, when I said it didn’t perform adequately, what I meant was that it worked, but the reductions in microbial counts during the challenge test weren’t fast enough for it to pass - an additional preservative was needed
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do you add the caustic soda as a powder, or as a solution?
try it both ways and see if it makes any difference
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@Perry strictly speaking, a hydrocarbon is a compound which contains only hydrogen and carbon
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unfortunately, due to the nature of these products, it impossible to create a product like this which is both all natural and performs to the required standard; one reason, and this is by no means the only one, is that cosmetic pigments are all to some extent artificial
it’s a bit like trying to built a house that’s by the sea but also located near Leicester city centre - you can have one or the other, but not both
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what’s the pH?
if it’s much above 5.5, your preservatives will be ineffective
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@JulietK Lameform TGI can be used as an O/W co-emulsifier, but only in combination with another, high HLB emulsifier, and there isn’t one listed here; and it is not physically possible to create an O/W emulsion with the listed ingredients
you’re right in that electrolytes are usually used to stabilise the water phase in W/O, but they are not compulsory, and given that there are no other stabilisers listed (long-chain polymeric emulsifiers, or oil-phase rheology modifiers) my hunch is that it’s been manufactured using an Ultra Turrax or a similar very high shear mixer, and the emulsion is stable by virtue of having a very small droplet size
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personally I’d lean towards W/O, based on the fact that polyglyceryl-3 diisostearate is a W/O emulsifier, it’s high up in the list, and the only potential O/W emulsifier listed (polysorbate 20) is a) ineffective; and b) very likely not present in a substantial enough quantity to affect the product as a whole
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@Shubh123 the HLB value you’ve quoted for caprylic/capric triglycerides is for a W/O emulsion - the figure for O/W is closer to 12
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@DRBOB@VERDIENT.BIZ probably not on its own, but the fact there’s a large amount of acid and electrolyte is very likely to prevent growth
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that depends on whether you have something to heat it with
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as castor wax is not surface-active, I assume you mean the required HLB value
personally I’d assume it has the same required HLB as castor oil, as the only chemical difference is that hydrogenated castor oil has no double bonds, and that change doesn’t affect the overall polarity of the molecule
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another good configuration is with the shaft at an angle to the surface, so the vortex is relatively small, and generally not coaxial with the shaft
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@Belassi the sodium stearate acts as a gelling agent, and makes the product solidify
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that depends: do you know about mathematical modelling of dynamic chemical equilibrium, and a programming language of some kind?
if the answer to both of these questions is ‘yes’, then you can
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personally, I’d be tempted to remove the cocoa butter - that’s notorious for crystallising in the cooldown phase, and causing products to become grainy / crumbly / otherwise unsatisfactory if it’s cooled too slowly
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there is no logical reason why using cetyl (C16) alcohol instead of cetearyl (C16/C18) alcohol would change the product’s ability to form an emulsion - or even why the emulsion failed to form in the first instance
to my mind, this suggests one or both of the following:
1. the emulsion cannot be consistently formed using this particular combination of method and materials
2. the ‘cetearyl alcohol’ you used before is actually a different material
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the first batch I ever manufactured myself was 8 kg of Marks & Spencer peach foam bath, as part of a cost-of-product reduction exercise: they’d cut back the fragrance and surfactant levels slightly, and needed samples to make sure it was still acceptable to the consumer
after that I made the five other variants in the range; after I started using a new lot of SLES halfway through the run I learned first-hand just how variable surfactant-based products can be in terms of pH and viscosity, even when all the materials are weighed out with rigorous accuracy
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because pH meters are electrochemical devices, the relevance and reproducibility of any readings depends on the conductivity of the product, which in turn depends on its composition
as the conductivity decreases (whether this is due to a lack of ionic salts, or the presence of non-conductive co-solvents), the measured pH readings will become less accurate, less consistent and less meaningful overall
in anhydrous products and W/O emulsions, the continuous phase generally has little to no electrical conductivity, so any readings are essentially meaningless
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@johnb I fully agree with you: the purpose of my post was to provide additional information about why the major branders did what they did
@David given that a number of national authorities within the EU have impounded products containing perborates, and barred them from sale on the grounds that perborate and borate salts are category 1 reprotoxins (see RAPEX reports for details), I’d personally err on the side of caution and steer well clear of them
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agree with @Bobzchemist - I’d suggest adding a polymeric emulsifier, e.g. PEG-30 dipolyhydroxystearate
also, the relative ratio of the two phases is irrelevant - the nature of the emulsifiers, and that factor alone, determines the nature of the emulsion
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personally I’d leave glycerine out; it’s not very miscible with oils, and it’s probably the root cause of your problem
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@johnb the concern is very real, and arose from its classification under the Globally Harmonised System of chemical classification (which was passed into European law in 2008)
because of this, it’s been classified as a Substance of Very High Concern under REACh regulations, which means there is a legal requirement for its usage to be tightly monitored, and for its usage in place of less contentious alternatives to be justified
in thise case, the branders clearly felt the case for continued use wasn’t strong enough, and it was simpler to use an alternative material that did the same job
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how are you manufacturing this product?
forming emulsions requires a certain technique, or else it can go disastrously wrong
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borax is a category 1B reprotoxin, personally I’d avoid it altogether
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@jeremien I’d disagree - there are a few situations in which the shape, and hence the size, of the surfactant/emulsifier plays an important part in determining the overall properties of the system
one example is the difference between using stearyl alcohol ethoxylates and oleyl alcohol ethoxylates as emulsifiers
the two are almost identical in terms of chemistry and HLB, but you get very different emulsions because the latter is wedge-shaped rather than linear, and takes up more space at the interface than the former