[ngarayeva001]

I made this in late June. A simple moisturizer with 10% of tetrahexyldecyl ascorbate. I don’t have a formula in front of me now, but there’s nothing suspicious in it. Only non prone to oxidation esters, some dimethicone, chelators, antioxidants (BHT, tocopherol), emulsified with arlacel 165 and 0.3% of Sepimax Zen, preserved with parabens. I am subscribed to several Facebook formulation groups, and remember 6-7 people complaining that it happened to them as well. If this is not a typical reaction the only thing that comes to my mind that there might be something wrong with the material sold on DIY market (repackers). Maybe they don’t store it properly or something.. 

[ngarayeva001]

I either don’t use vegetable oils or make sure those are not high in polyunsaturated fats. I add BHT and tocopherol. I don’t use any sort of botanical extract. They still oxidize.

[ngarayeva001]

I don’t know why is it happening but the experience I have with antioxidants so far, they cause oxidation rather than prevent it. I have this issue with ubiquinone, resveratrol and tetrahexyldecyl ascorbate which is an oil soluble derivative and claimed to be stable.. I know that some might say it’s anecdotal evidence and those are perfectly good ingredients but I heard the same from other people. Maybe I am doing something wrong with all these antioxidants. 

[ngarayeva001]

There are too many inputs for w/si that can affect viscosity. Post the entire formula. What emulsifier are you using?

[ngarayeva001]

Yes, you should count cetearyl alcohol as a lipid

[ngarayeva001]

I made many moisturisers with NAG and Niacinamide (O/W and W/O, different oil phase, different emulsifiers) and they don’t oxidise. I am pretty sure it’s resveratrol. Are you using a powder or a version solubilised in PG?

[ngarayeva001]

What is the definition of ‘mild’?

[ngarayeva001]

BTMS-50

[ngarayeva001]

Adding to the above, if you are new to formulation my advice is to stick to commercial blends for now. Such as Arlacel 165. It has HLB of 11 but works pretty much for all oil combinations (veg oils, synthetic oils or esters, silicones might be a different story). You can use it say with pure Almond oil which has HLB of 6 but it will emulsify it. Especially if you add stabilisers (carbomers, gums, polymeric emulsifiers). HLB is useful if you are trying to make your own blend of low and high HLB of non-ionic emulsifiers. Like Croda’s tween plus span combo.

[ngarayeva001]

HLB is only useful for non-ionic emulsifiers. The system doesn’t tell you how much of the emulsifier to use either and you must figure it out via trial and error.

You need to calculate weighted average HLB of all oils, waxes and other oil soluble items in the oil phase. Then you need to match high HLB and low HLB emulsifiers to the HLB of total oil phase.

[ngarayeva001]

“Do I need to emulsify the cetearyl alcohol also?” if your question is whether you should count cetearyl alcohol in your HLB calculation as oil the answer is yes.

[ngarayeva001]

@MarkBroussard, I probably should have specified. Bella82 said, that she is not going to add water. In her updated formula there is only 1.2% of BTMS. Since glycerin is watersoluble, it should be treated as water in this formula and as you said, it is going to be a glycerin based emulsion. I don’t think that 1.2% of BTMS will be sufficient to stabilise such a product.

And in general, 10% of glycerin in hair product, might feel very sticky.

[ngarayeva001]

Glycerin is water. Are you trying to create cationic water in oil emulsion here? What is that product supposed to do in general? What is hair moisturiser?

[ngarayeva001]

Too much oil, wrong approach to emulsification system, not a broad spectrum preservative. Do you add any water at all?

[ngarayeva001]

Thank you for the polyglycerol esters doc. I will give it a proper read. 20%… the logic comes from Croda’s formulas. They dump 20-30% of emulsifies in their microemulsion oil cleansers. I figured out in an empirical way that it’s super irritating for eyes (and supplies exaggerate amount of materials in general) but I thought that for bath oil should be ok. Thank you for suggestions. I will run more experiments with low hlb emulsifiers only and see if that works. I have a large bottle of sorbitan oleate for which I have no use. If it works I will kill two birds with one stone.

[ngarayeva001]

You don’t have enough waxes for a paste. I think you should up it to at least 10%.

[ngarayeva001]

I understand this is not what was asked but if you want to add something negatively charged to stabilise the formula, make a non-ionic emulsion with conventional emulsifiers and add polymeric emulsifiers (Sepinov, Zen etc). The most of them are anionic and the difference in texture will be very noticeable.

[ngarayeva001]

Polyglyceryl-4 oleate has an HLB of 5 https://www.makingcosmetics.com/Polyglyceryl-Oleate_p_131.html
Almond oil is 6 so it was mostly polyglyceryl-4 oleate and small amount of poly 80. Still sinks.
When I say does not work I don’t mean that the blend fails to create an emulsion in water. They all do (all combinations above) but the emulsifier sinks to the bottom of the bottle and I need to shake it. I agree it’s not an emulsion to calculate HLB but I was looking for a way to stop separation and just tried that to see whether it helps.

[ngarayeva001]

Stearic acid when used as coemulsifier is just added up to the oil phase (Pharma’s formula). When you use TEA-stearate as an emulsifier there’s no sense to calculate HLB, because it’s anionic. HLB system is only useful for non-ionic emulsifiers. Post an entire formula and it will be easier to comment on qualities of emulsifiers. 

[ngarayeva001]

Thank you @Bill_Toge. I tried polyglyceryl-4 oleate and sorbitane oleate in combination with Polysorbate 80 (to bring HLB of an emulsifier to the same as oil). It separates after some time (not right away). I will try it alone and see how it works 

[ngarayeva001]

Very useful information! I have both octyldodecanol and ethylhexyl stearate and will experiment with mixing different polarities. Thank you!

[ngarayeva001]

There’s so much misinformation now and although they are a minority but most vocal customers don’t just want healthy skin they want to make a social statement and feel more moral and virtuous  than the general crowd. So all this obsession with natural/gluten/paraben/silicone /sulfatefree/vegan/ethically source 
free of toxic chemicals nonsense.

[ngarayeva001]

All these extracts are added at tiny amounts in commercials products. Look through LOIs of a couple of benchmarks and you will see that the extracts are clearly below 1% line.

[ngarayeva001]

@Pharma, as always thank you very much! There is a surfactant called Cithrol 10 GTIS by Croda (but it’s expensive and I need to ship it from Italy while poly 80 is like £5 for a lt). It is used specifically to make such products. I noticed that when they mix it with mineral oil (I am referring to Croda’s formulas), they always add PG. I thought it was a waste, but now I understand why.

Funny enough, the conconctions with polysorbate 80 are stable for more than 15 minutes but you need to shake them before use. And I don’t want to do it because if it separates and you need to shake it I take it as a failure :smiley:

I tried low HLB liquid emulsifiers but they create w/o.. I will continue experimenting now when I have more clarity of the reasons behind the separation. As a default option I have one stable version: 20% Poly 80 and 80% C12-15 Alkyl Benzoate.

[ngarayeva001]

Hah! I noticed that brand recently. Was even thinking to post one of their LOIs here. I think what is happening, they add preservatives and just say that they don’t. Who is going to catch them? Many of these natural brands use emulsifiers and then claim they don’t have anything but pure organic coconut, “healing and soothing” lavender and tears of virgins in their product. Which makes me think they overcame laws of physics and used some form of magic to persuade water and oil stay together.

Jokes aside, I have been binge watching a youtube channel called Nile Red (a chemist running interesting experiments on camera) for a while and noticed an interesting video. So, this guy wanted to see if he can reverse saponification process. He wanted to take a soap, restore fatty acids through chemical reactions and somehow attach back the glycerol to restore triglyceride structure. The final goal was to make french fries with this oil
To make his life easier he took a mono oil soap. The LOI claimed it’s just olive oil, no dyes, no preservatives, no fragrances. Having some understanding of soap making, I could tell right away that this “pure” soap had s#%t load of green colorant in it. Not being in the personal care formulation world and not knowing how this “pure” brands fake LOIs, the chemist assumed they say the truth and thought maybe it’s green because the oil was not well refined. He failed his experiment and maybe that was the very reason.