[Bill_Toge]

in my experience, a water-free high HLB surfactant (e.g. Tego Care 450, INCI Polyglyceryl-3 Methylglucose Distearate) can easily be included in anhydrous products, provided that you also have a suitable dispersant, e.g. polyglyceryl-3 polyricinoleate

[Bill_Toge]

it’s used to accelerate phase separation; benzyl alcohol is also used for this purpose, and to ensure clean separation of the phases (it helps dissipate entrained air in the oil phase, not sure how or why)

[Bill_Toge]

if you have a sufficiently stable emulsification system, you can easily add water-soluble material when cool, provided that you keep any high-shear mixing to the absolute bare minimum

[Bill_Toge]

try food-grade sodium or potassium ferrocyanide; they’re widely used as anti-caking agents in table salt, which is highly hygroscopic

[Bill_Toge]

this silica manufacturer’s guide gives plenty of detail

https://products.evonik.com/assets/46/21/244621.pdf

[Bill_Toge]

I’d suggest getting rid of the PEGylated oil altogether; it’s not necessary, and is likely contributing to the formula’s tendency to draw water from the air

I’d also suggest getting rid of the IPM, as it’s not miscible with the rest of the stick, and stick formulas are best kept monophasic

[Bill_Toge]

yeah, this is definitely fake

solubilised azelaic acid products that strength are all emulsions; being both highly polar and hydrophobic, it’s a notoriously difficult ingredient to solubilise, unless you use something like N,N-dimethyl formamide as a co-solvent (which is not in the slightest bit suitable for topical use, being highly toxic)

[Bill_Toge]

sublimed sulphur is usually finer and purer than precipitated

[Bill_Toge]

Oxford are legit, but if the person preparing the assessment is the same one we used to deal with, they are not the sharpest tool in the box

for instance, they refused to certify one of our products because it contained melatonin and was therefore a medicine(???), completely ignoring the fact that a) it was topically applied and not ingested, as medicinal melatonin is; and b) melatonin has no legal restrictions in cosmetics

[Bill_Toge]

another possibility is that the chemist(s) involved didn’t really know what they were doing and just threw everything bar the kitchen sink at it - which is particuarly likely if the product was formulated in the UK

[Bill_Toge]

VP/VA and PVP combined are more flexible and a lot less flaky than PVP on its own

high-viscosity PVP will give you a viscous gummy texture at low levels in a way that few if any other styling resins can - K-90 is a good balance between high viscosity and practicality of usage

also, if the benchmarks are manufactured in China (many are, in my experience), the ingredients list is likely to bear little resemblance to the actual product, a lesson I learned the hard way

[Bill_Toge]

try adding PVP K-90 - it’ll thicken the product and have a big effect on sensorials, unlike Luviskol VA 73 W

Luviskol VA 73 W is definitely worth keeping in, as it’s a lot less prone to flaking than PVP

[Bill_Toge]

HEC hydrates most quickly in neutral or alkaline conditions, is thinned by surfactants, and is generally slow to hydrate

the best material of that family for thickening bodywashes is hydroxypropyl methyl cellulose, which also acts as a foam booster

[Bill_Toge]

isoamyl laurate is a thin fluid with low viscosity, and lauryl laurate is a wax; the former will give a lighter and less greasy skin feel than the latter

[Bill_Toge]

OliviaLeigh said:

@Bill_Toge Hi Bill, I found this on Research Gate -  Formulation and Analgesic Effect of Sodium Hyaluronate and Magnesium Sulfate Combination in Rats Following Intra-articular Injection: Hyaluronate Combined with Magnesium Sulfate for Rapid Analgesic Effect

Would this be okay to use in my formulation then? 

I am getting better at understanding these papers but not ???? confidant yet ????

the best thing to do is try it and see for yourself - you can only get so much information from scientific papers

[Bill_Toge]

I made about 500 grams of old-fashioned soap based shaving cream at home several years ago, using materials from various online shops who supply to individuals - a little goes a long way and it’s still good, several years later

none of them sold coconut fatty acids though, so I had to make this myself by saponifying and then acidifying coconut oil

[Bill_Toge]

hydrogenated castor oil (not PEG-40 hydrogenated castor oil!) is the same thing as castor wax; in my experience, around 5% w/w is effective

castor oil has some unique chemistry (hydroxyl group on the 12 position of the fatty acid) that becomes evident when it’s hydrogenated; other hydrogenated oils don’t show the same gelling effect as castor oil

I don’t know about the compatibility of sodium hyaluronate with magnesium salts, I’ve never tried combining them

[Bill_Toge]

something worth bearing in mind, and which is rarely explained, is that magnesium or calcium salts improve stability by increasing the surface tension of the water phase, and reducing its (normally very high) tendency to aggregate; magnesium sulphate is typically used because of its high solubility

I would also suggest adding a few % of castor wax to gel the oil phase and improve thermal stability

[Bill_Toge]

+1 for polyglyceryl esters

you’ll also need a rheological stabiliser to keep the product non-fluid at rest, or else it’ll separate

[Bill_Toge]

@ariepfadli except you need a base for it to become deprotonated, which this formula doesn’t have, and stearic acid is not soluble enough in water for water to act as a base

[Bill_Toge]

@PhilGeis that’d be ISO 11930, which is a lot more rigorous than the USP/BP challenge test

[Bill_Toge]

when it comes to not leaving an oily residue, non-volatile alkanes with a low viscosity (isododecane, isohexadecane etc.) and low molecular weight silicones are even better tools for the job, as they hardly interact with the stratum corneum at all, due to being non-polar and therefore immiscible with nearly all of its components

[Bill_Toge]

I’ve tried it (and many other solvents) - it doesn’t work

[Bill_Toge]

I’m not convinced - having spent many hours working with it on the bench, I know that azelaic acid is poorly soluble in damn near everything, including propylene glycol

[Bill_Toge]

if it contained that much azelate or other salts, the carbomer gel wouldn’t retain its structure

also, as it’s diprotic, azelaic acid would need a staggering amount of caustic soda to neutralise