[Bill_Toge]

at my old place we used to make and fill two-phase mouthwash; each phase was made and filled separately, as trying to fill the mixed product would have been far too complicated and impractical

[Bill_Toge]

any regulation is useless unless it’s effectively enforced

for instance, I’ve been quite shocked to learn that mouldy/bacteria-blighted products, from major branders no less, are sold as often as they are in the US, as products in such a state over here would be quarantined and barred from sale by Trading Standards, who would then advise the brander to recall the product, with a high likelihood of criminal prosecution if they fail to do so

having to recall products in this way would be a complete disaster, particularly for a major brander, so reputable manufacturers take extra care to ensure their products are sterile at the point of sale

the regulations over here are less stringent than they are in the US, but in practise, the consequences of failing to meet them are much more severe

@BartJ @perry and if you only count the ones that have been banned based on the advice of scientific committees to the European Parliament, you’re talking about several dozen, probably not more than 100

an awful lot of the materials on Annex II are things you wouldn’t put in cosmetics anyway (arsenic, asbestos, hormones, etc.), including illegal drugs (e.g. barbiturates, LSD)

[Bill_Toge]

you were right to ask, it doesn’t make any sense!

[Bill_Toge]

I suggest you check that a) the formulas can be reproduced consistently in the lab, and b) the manufacturing procedures are actually being followed on the plant; in my view, problem is most likely to lie in one or both of those areas

the best way to check b) would be to supervise the manufacture of a batch, in person, from start to finish

also, it seems a bit strange that R&D would get involved in this rather than quality; reminds me of a certain British manufacturer who made their entire QC department redundant ‘because batches were taking too long to pass’

[Bill_Toge]

cosmetic-grade micas are perfectly safe to use as is

where did you hear they were toxic?

[Bill_Toge]

in the second column of both tables, x stands for the mole fraction of ferulic acid; in other words, what proportion of the molecules in solution is ferulic acid

e.g. the first line states that at 298.2 Kelvin (25 °C), 8.03% of the molecules in the solution are ferulic acid, and 91.97% are ethyl lactate

to convert this to % w/w, you have to multiply the mole fraction of each component by its molecular weight, then determine what proportion of the total weight is ferulic acid

0.0803 mol × 194 g/mol = 15.5782 g ferulic acid
0.9197 mol × 118 g/mol = 108.5246 g ethyl lactate

total weight = (15.5782 + 108.5246) g = 124.1028 g

%w/w ferulic acid = 15.5782 g ÷ 124.1028 g = 0.12553… = 12.6%

@Belassi that’s academics for you - I took it to mean a mixture of 98.6% w/w ethyl lactate and 1.4% w/w water (as a residual impurity from the manufacturing process)

[Bill_Toge]

those products owe their texture and viscosity to large amounts of ceteareth-25 or other long-chain fatty alcohol ethoxylates; for this reason, they are very different to carbomer gels

[Bill_Toge]

depends what kind of conditioning agent you use; if they’re dispersed correctly, many polymeric quaternaries (e.g. PQ10) are perfectly compatible with anionic surfactants

[Bill_Toge]

@Zink the quality of the film is a huge influence on SPF, don’t underestimate it!

[Bill_Toge]

if there are similar studies for oleic acid you could in principle use their findings as a rough guide, seeing as they’re structurally very similar

[Bill_Toge]

cetyl dimethicone also helps the product form an even film, which (in principle at least) would help boost its SPF score

[Bill_Toge]

@Microformulation if you want the chapter and verse in the EU regulations, the relevant Annexes are III/45 and V/34; the former covers its use in fragrances, and the latter covers its use as a preservative

[Bill_Toge]

yeah, several UK supermarkets have been phasing parabens out of their own-brand products over the last 5-10 years; major branders, on the other hand, generally have not

[Bill_Toge]

you might be able to make it; can you get hold of maleic acid, and do you have the equipment to carry out an ozonolysis reaction?

[Bill_Toge]

@cherri colour cosmetics are very easily contaminated, as they come into direct contact with the skin and are used repeatedly; for that reason it’s always wise to include a preservative

[Bill_Toge]

a bit of googling shows that “Acrylates/C10-30 Alkyl Methacrylate Copolymer” is a thickener from BASF, and “Maltodextrin / VP Copolymer” is a styling polymer from Akzo Nobel

your product is thin because the latter is not a thickener, and there’s not enough oil phase or emulsifiers for the product to have any substantial viscosity on its own

[Bill_Toge]

the largest concentrations of UK manufacturers are in south-west England (Somerset, Devon, Wiltshire) and on the M62 corridor (Merseyside, Greater Manchester, West Yorkshire)

there are a few in the south-east, but I don’t know of any within London itself

[Bill_Toge]

having experimented with numerous would-be preservatives for mouthwash a few years back, I can say that numbness is a characteristic effect of phenoxyethanol and benzyl alcohol; not irritating per se, but it is unpleasant

for loose powders, you want a preservative that’s a loose powder too - sodium benzoate, potassium sorbate and sodium methyl paraben are the most commonly used ones

[Bill_Toge]

I recall someone on here had a similar problem not so long ago, with black bits appearing in their product after they’d filled it into in aluminium tins

aluminium is a very reactive metal, and if part of the internal lacquer/coating is thin, it can leach into the product - I think this is what’s happened here

in my view using a stainless steel (i.e. inert) vessel, as used in industrial production, is the simplest solution

[Bill_Toge]

there’s no (declared) emulsifier, it’s not surprising it separates

[Bill_Toge]

in the EU, there is no legal limit on arbutin, but two recent SCCS opinions have found alpha-arbutin safe up to 2% (in face creams) and 0.5% (in body lotions); and beta-arbutin safe up to 7% in face creams

beyond these levels the margin of safety is unknown; fore this reason, many safety assessors are likely to reject a product if it contains a higher level

opinion on alpha-arbutin
opinion on beta-arbutin

there is no legal limit on glycolic acid, but the current opinion recommends maximum 4% and a pH of at least 3.8, with appropriate warnings on the pack

D&C Blue 4 (FD&C Blue 1) would be declared as “CI 42090”, and this is covered by Annex IV/63

hope this helps!

[Bill_Toge]

you definitely won’t find a solvent that meets point 2)

silicones are non-polar, so ionic salts won’t dissolve in them

[Bill_Toge]

@DavidW that’s a textbook example of marketing behaviour

they’ll happily clear a potentially contentious product for launch if it works well on a small sample, but if one person in their department isn’t 100% satisfied then the whole project is likely to get the plug pulled on it with no notice, even if they’ve already committed to an order and paid for it

[Bill_Toge]

from a bit of googling, I found out that the parent company (AOBiome LLC) has a lot of senior staff with experience in the pharmaceutical industry, and the company appears to be doing clinical trials with these bacteria with a long-term aim of using them in medicines

so on the surface at least, they don’t seem to be your average fly-by-night snake-oil peddlers

with that in mind I’m guessing, maybe optimistically, that the products are made under sterile conditions, and to order; given their short shelf life, trying to manufacture and store large amounts of them would be a logistical nightmare

@BartJ that product most likely passed a challenge test because there was not enough available water for microbes to survive in it

[Bill_Toge]

if it were a W/O emulsion it’d float on top of the water, rather than settle to the bottom

given how much water there is in the formula, it would also be extremely viscous and probably very difficult to shear

and given the very low level of low-HLB emulsifiers, it would likely undergo a lot of ‘bleeding’ as it cooled (i.e. water separating from the bulk product)

in short, I don’t think it is W/O