[Bill_Toge]

the limit for peroxide in oral care cosmetics is 0.1% w/w as hydrogen peroxide, as per Annex III/12 of the regulations

so for calcium peroxide, the limit would be 0.1% × (72 g/mol ÷ 34 g/mol) = 0.21%

if you want to use more, you’d have to look into getting your product made and sold as a medicine

[Bill_Toge]

for what it’s worth, many years ago we used to manufacture a mixture of coffee grounds and powdered indigo, and sell it as a brown hair dye

[Bill_Toge]

emulsifying wax contains at least one high HLB surfactant (polysorbate 60 among others), so it’s impossible to form a W/O emulsion with it

the relative volumes of the oil and water phases are irrelevant - the nature of the emulsion depends entirely on which emulsifiers are used

[Bill_Toge]

try http://www.gracefruit.com, they’re based in the UK and have quite a wide selection

[Bill_Toge]

it’s related to thymol and carvacrol, but different to both, and it has much weaker odour than either

the difference is most obvious from the IUPAC names:

thymol: 2-isopropyl-5-methylphenol
carvacrol: 5-isopropyl-2-methylphenol
o-cymen-5-ol: 4-isopropyl-3-methylphenol

in the EU it’s only permitted as a preservative, with a limit of 0.1% (minimum inhibitory concentrations are 0.02-0.07% depending on the species)

[Bill_Toge]

corrosion shouldn’t be a problem if the spring is made from good quality stainless steel - you’ll just have to try it and see

[Bill_Toge]

you could also try alibaba.com; a number of suppliers claim to sell in lots of 1kg or less, and some claim to sell VP/VA copolymer too, in similar quantities (these are the two generic non-proprietary resins widely used in this kind of product)

as always, be wary when ordering things from China!

[Bill_Toge]

what you need is a film-forming resin, which gum arabic and CMC are not

most resins suitable for haircare are related to PVP, and many of them have no effect on viscosity at all

[Bill_Toge]

I’d start with 5% cetearyl alcohol rather than 10, unless it’s incredibly thick

behentrimonium chloride has a higher melting point than cetrimonium chloride, and it forms more stable emulsions

[Bill_Toge]

as it’s not a cosmetic, a medicine, a foodstuff or a detergent, it would most likely fall under the general legislation for chemicals and mixtures, so you probably wouldn’t have to declare ingredients on the pack

you’ll have to double check this though; I’m no expert in US law

if the mixture is hazardous, you would have to declare those hazards on the pack in a manner prescribed by the relevant legislation and the GHS (Globally Harmonised System of Classification and Labelling of Chemicals)

[Bill_Toge]

@kinome the product described in the patent I linked, which sounds a lot like Hairprint, is an oxidative colour based on L-DOPA and iron/manganese salts rather than traditional bases and couplers (PPD etc.) - so not very similar to henna at all

I’ve also realised it’d be a complete nightmare as far as safety assessment is concerned - the oxidative nature of this product means its exact composition at the point of use (hence, its toxicity) is completely unknown, unless there’s a very rigorous and foolproof study out there somewhere

(apropos of nothing, the patent reads like it was written by an academic research group rather than by cosmetic chemists; the way they’ve written the formulas and methods is a dead giveaway)

[Bill_Toge]

further to @Belassi‘s comments I found this patent, filed by the company who owns the brand (Warner Babcock Institute for Green Chemistry), which goes into detail

the long and short of it is that it uses the iron and manganese salts, and peroxide, to accelerate the process

[Bill_Toge]

+1 for the COLIPA guidelines

there is no standard because stability testing is not a rigorous science, and is essentially a guessing game; you just have to evaluate all the data as a whole, draw a conclusion from it and make a judgment call based on that conclusion

I’d recommend doing freeze/thaw cycles as well, as it highlights the difference between an intrinsic instability and a heat-related instability, and gives you an advanced alert of any low-temperature instability that might not be immediately evident

[Bill_Toge]

what I mean is that the products claim to have an SPF of 25, they scored between 30-40 on the in vivo test, and we get consistent results on the Labsphere between 30 and 45

the sunscreens in those products were titanium dioxide, ethylhexyl methoxycinnamate and homomenthyl salicylate

if you’re using a sunscreen-grade zinc oxide dispersion, it will have a hydrophobic coating, therefore none of it is soluble, therefore the concentration of zinc ions in the product is minimal to nil

also, titanium dioxide in sunscreens is every bit as inert as zinc oxide, regardless of what the state of California says about it

[Bill_Toge]

try an alkyl glucoside (decyl glucoside, lauryl glucoside, coco-glucoside etc.)

low HLB surfactants don’t foam, and because foaming surfactants are generally not effective as emulsifiers, their HLBs are irrelevant

[Bill_Toge]

in my view your best bet is to consult a fragrance house that does flavours too - to the best of my knowledge, there are very few (if any) consultants in this field

[Bill_Toge]

in my experience, in vitro measurements (e.g. on a Labsphere) correlate well with in vivo results; we produce a range of products with SPFs and use the Labsphere as a QC check, since the results are consistent with the in vivo test report

the rheology of the product, hence the quality and evenness of the film, is a very important factor influencing the SPF, so yes, the thickener does matter - what you want is a short-flow, strongly shear-thinning product that forms an even film when applied to a surface

carbomers and clays (Veegum/Laponite) are generally the best choice for rheology modifiers, but many others are effective

as for boosting SPF: titanium dioxide absorbs more strongly than zinc oxide, but zinc oxide provides a broader spectrum of UV protection, so you might want to consider using a combination of the two

[Bill_Toge]

honey is mostly sugar, i.e. microbe food; any preservative will really struggle to prevent growth in a product with that much honey in it

[Bill_Toge]

@HuskyBeard on the other contrary, it would be an “article (other than food) intended to affect the structure or any function of the body of man”, which puts it firmly into the medicines category

[Bill_Toge]

a product like that would be regarded as a medicine anywhere in the world - the fact that other branders use weasel words to try and sell their products as cosmetics doesn’t make them legally compliant or in any way defensible

you could certainly try to sell it as a cosmetic, but if it blew up in your face and you ended up being taken to court over it you’d only have yourself to blame

[Bill_Toge]

hmm, that’s a difficult one; foaming products and emulsions usually work against each other

however, you can by adding a little bit of a foaming surfactant to the water phase, e.g. SLES, and a suitable protective colloid to stabilise the emulsion - I’ve done this with cream hair dyes so they wash out more easily

be careful not to add too much of the foaming surfactant, or else it’ll compete with the emulsion for the available water and cause separation

and @Belassi is right, alcohol will kill the foam completely

[Bill_Toge]

@David as I said above, to the best of my knowledge there are no ozonides, organic or inorganic, that have registered INCI names, or are stable enough to be used in consumer products

the only time I’ve ever come across them are as reactive intermediates in an organic synthesis

[Bill_Toge]

@johnb funnily enough, ozone actually has a registered INCI name and it’s not subject to any restrictions in the EU - probably because nobody uses it

in the dim and distant past I can remember using it for ozonolysis reactions in the lab; the smell is very harsh, nearly as bad as sulphur dioxide, and once you’ve smelt it you never forget it!

[Bill_Toge]

first of all, ozone and ozonides are two different things

ozone is a dark blue, acrid-smelling gas that acts as a strong oxidising agent and decomposes readily in aqueous solutions; if you put it in a cosmetic product I very much doubt it’d remain stable for long enough to act as an effective preservative

ozonides are either inorganic salts of ozone (just as unstable as ozone itself, and often explosive), or adducts of ozone to organic compounds; the latter are also unstable, and the majority of them don’t even have INCI names

in my view, even trying to create a stable formulation with either of them, let alone trying to get it to pass a challenge test, would be completely impractical

[Bill_Toge]

in my experience, airless packaging is very robust; as long as the closure fits properly and consistently, you shouldn’t have a problem with an alcohol-containing product