[Bill_Toge]

the HLB system is only one of the factors that determine emulsion stability

firstly, you need to ensure your emulsifiers and oil are chemically compatible with each other; if they’re not, then they won’t mix or stay mixed at all, regardless of what the HLB system says

secondly, you need to ensure your emulsified oils cannot physically separate from the water phase, or can only do so with great difficulty - and this is where your problem lies

because you’re making a thin, sprayable product, what you need is a rheology modifier that gives the formula some zero-shear viscosity (i.e. stops the droplets within the liquid from moving while at rest) - in a thicker product such as a cream or a paste, this can be achieved with a judicious choice of emulsifiers and oil-phase ingredients

if you want to keep the overall viscosity low, then Laponite clays and/or gellan gum work well

and your question is not basic at all - there are lots of otherwise knowledgeable people within the industry who don’t understand how emulsions work!

[Bill_Toge]

having used both, I would say there’s no significant difference between them

the only real reasons I’d hesitate to use either of them would be the fatty/soapy smell they impart to the product, and their tendency to go yellow over time

[Bill_Toge]

yes, we carry out packaging compatibility tests on everything that is destined to go to production, at the same time as the stability test; if the product is not appropriate for the pack type, if the pack/closure combination is inadequate, or if the packaging is poorly made, the compatibility test flags this up

and sometimes even just having the formula in packaging of different materials can give very different stability results - these are two drastic examples I’ve dealt with:

1. a pearlised shampoo which was fine in plastic, but separated when tested in glass

2. a hair dye containing HC Blue No. 2, which experienced a slight pH decrease in glass, and a much more rapid pH decrease in plastic, followed by a severe colour change once it fell below pH 5

[Bill_Toge]

it is possible, but in the EU at least it’s restricted to 0.1% (far too little to have a substantial effect), also, regardless of the concentration, you’d have to get the pH down to 2-3 for it to remain stable throughout the product’s shelf life

and a toothpaste that acidic would do appalling damage to the teeth

personally, I wouldn’t bother

[Bill_Toge]

you can’t directly add anionics to PQ-10, but an overall mix can be successfully done using a particular technique - details can be found on page 17 of this manufacturer’s brochure 

for what it’s worth, 0.5% is quite a high level for PQ-10 generally, and particularly for this formula; you may struggle to achieve clarity

[Bill_Toge]

further to the above, I keep a list of naturally occurring plant / flower / fungus extracts that are considered so harmful they’ve been explicitly banned from cosmetics, just to demonstrate that what’s natural ain’t necessarily good for you

going back to the main question, I’d quite like to know what it is about hot-fill styling products that makes customers so flaky and indecisive when it comes to picking what they want and sticking with it

[Bill_Toge]

depends where they’re sourcing it from; if it’s come from China then the written ingredients list is likely to bear marginal (if any) resemblance to the actual product

and if it washes out easily, it will be water-based; I know from experience that you can formulate very wax-like O/W emulsions if you use the right emulsifiers and rheological additives

[Bill_Toge]

that’d be because it’s a direct colorant

all direct colorants are PPD-free by nature; you’d only ever use PPD in an oxidative colorant (it’s colourless until it undergoes oxidative polymerisation)

“PPD-free” claims on direct colorants are technically correct, but given their context, they’re nearly as nonsensical as “gluten-free” claims on bags of salt

[Bill_Toge]

since the ES-5227 Formulation Aid is described as being “grey white to milky white” on the SDS, and all the others are “clear to slightly hazy”, I’m guessing it’s that

the polysorbate 20 is there to form a transient emulsion which lasts long enough for the product to be usable in its mixed form, but which also breaks down over time

sodium chloride increases the surface tension of the water phase, and ensures the two phases separate cleanly, so that any partitioning/leaching from one phase into the other is kept to a minimum

surface tension is also the reason why it’s used in W/O emulsions, though in that case it’s to stop the water droplets from coalescing rather than to promote separation

(I found out a lot of this stuff because the last place I worked was the UK-based contract manufacturer for a very well known brand of two-phase mouthwash)

[Bill_Toge]

cocamide DEA is not a carcinogen

it can form carcinogenic substances in the presence of a very specific type of preservative which is rarely if ever used in cosmetics these days, but it is not carcinogenic in itself

[Bill_Toge]

that’d be your TEA - at that level it’ll cause serious yellowing

just out of interest, how come your acrylates copolymer (hence, your TEA) is in at such a high level?

[Bill_Toge]

since the vast majority of liquid cosmetic-grade surfactants are sold as dilutions in water, your only really viable option is to try and dissolve solid surfactants in your glycerine/glycol solvent

sodium lauryl sulphate, sodium lauryl sulphoacetate and sodium cocoyl glutamate (in increasing order of price) are three such surfactants that I can name off the top of my head

[Bill_Toge]

for what it’s worth: both glycol stearate and Tween 80 are very poor emulsifiers, because they are respectively too hydrophobic and too hydrophilic to effectively mix with both the oil and the water phase

[Bill_Toge]

having seen the photo on the website, the product definitely looks like an emulsion

and CI 75120 is a water-soluble dye, so it would be a little silly to use it in an anhydrous product

also, the INCI list is evidently incorrect and/or incomplete (“cera microcrystallina” is one ingredient, and there is no such thing as “hydroxaldehyde”; at a guess, it’s probably meant to be “hydroxybenzaldehyde” or “hydroxyisohexyl 3-cyclohexene carboxaldehyde”)

in other words: I don’t think it’s anhydrous at all

[Bill_Toge]

@mktan54 try Liquid Germall Plus (INCI: Propylene Glycol, Diazolidinyl Urea, Iodopropynyl Butylcarbamate)

[Bill_Toge]

is it definitely the ketoconazole that’s coming out?

(I ask as chlorhexidine gluconate is one of the most temperamental ingredients I’ve ever tried to formulate with, and will crash out of solution at the slightest provocation)

[Bill_Toge]

for what it’s worth: both phenoxyethanol and ethylhexylglycerin have low solubility in water, and are better suited to creams and emulsions rather than clear gels

[Bill_Toge]

there is no legal limit in the EU

don’t know where that figure of 2% came from but it certainly didn’t come from the European Commission or the SCCS

[Bill_Toge]

@Bobzchemist I don’t know of any white oxidative dyes either; they tend to be dull and dark in colour, as the base and the couplers often form ill-defined mixtures of oligomers rather than single products

and base/coupler combinations which give single products result in sharp, bright colours (e.g. red, pink, orange) rather than white

based on what I know about photochemistry, if you want to create a genuine white dye or oxidative pigment you’d need some incredibly wide absorption and emission bands, and an outrageously odd molecular structure; it’d probably make a good Ph.D project, but at this moment in time it just doesn’t exist in reality

[Bill_Toge]

what you need is a purple toning shampoo, to cancel out the yellow tones in bleached hair, leaving it silver/white

this product is an excellent example

[Bill_Toge]

leave out the Tego Betain F50

it won’t mix with the rest of the ingredients in phase B, and it’ll severely thin your Natrosol gel

just out of interest, why is it in there?

[Bill_Toge]

since the sodium salt of camelina seed oil doesn’t have a recognised INCI name (or even a CAS number for that matter) any declaration of it on the label would be spurious

in this instance I’d personally go for approach a) 

[Bill_Toge]

my view is that you have too many surfactants all round; these thin carbomers and carbomer-type polymers, and result in more Newtonian flow, which is not what you want for suspension

also, from personal experience, Carbopol Aqua SF-2 suspends particles very efficiently at low usage levels

a bonus of this is that lower levels = less trapped air

[Bill_Toge]

these shampoos often contain a small amount of sodium thiosulphate, or a similar reducing agent, to neutralise the chlorine - see Wikipedia for details

also, if memory serves, it makes isothiazolinone-based preservatives less effective, so you need to choose your preservatives carefully

[Bill_Toge]

vitamin C can reduce benzoic acid to benzene in the presence of soluble iron

without soluble iron, vitamin C is simply not powerful enough to do this on its own (if it were, it would be on every banned list in the world!)

if the base lotion has been made with deionised water, the amount of soluble iron - hence, the chance of this reaction occurring - is negligible

and with citric acid, there is even less possibility of this occurring, because unlike vitamin C, citric acid cannot act as a reducing agent

hope this helps!