[ketchito]

Please don’t get me wrong, but just reading your post, I don’t know if you’re willing to accept evidence-based information. Just as a side note, most Cocamidopropyl betaine use coconut or palm oil as one of the starting materials, probable same as the sulfoacetate you’re using.

[ketchito]

I believe you want to make a microemulsion. If that’s the case, I don’t believe you can do that from already formed macroemulsions, since it’s not only the process but the formula that form a microemulsion (eg. Specific types of surfactants, co-surfactants, small molecules, etc).

[ketchito]

It says its melting point is around 200°C (and the boiling at around 400°C), so unless there’s some reactant to cleave a bond within its structure, it should be fine to heat it in the water phase at 90°C.

[ketchito]

Can you make a sample without PEG-120 methyl glucose dioleate? In some systems, it tends to gel the product. What you see at the bottom might be water, and the upper part might be a surfactant-rich phase.

[ketchito]

You could make a microemulsion or use an ultrasound device, but the first requires advance knowledge on colloid chemistry (and specific type of surfactants), and the second requires special equipment.

Now, an oil phase of 1% migh not be worthy to make an emulsion, but if so, there are plenty of emulsifiers other than polysorbates (which are actually pretty safe), some in liquid form and/or water dispersible.

[ketchito]

You can also check all the series of “Handbook of detergents” (parts A to E), “Liquid Detergents” and the “SEPAWA proceedings”.

[ketchito]

Glyceryl stearate SE is still one of the best emulsifiers on the cosmetic market, and one of the best to get very stable lamellar phases. I don’t think these old materials get outdated (just ask guys like P&G, UL, L’Oreal and the likes, who spend millions of dollars on research and have the best cosmetic scientists, and yet still use very “old” ingredients 🙂).

[ketchito]

You could add an oxidant (like hydrogen peroxide), or a metal catalyst (if you could get iron chloride, that’d be great).

[ketchito]

The amount of water soluble extract is so small (consider that extracts at most have a 1-5% concentration of the real active and the rest is just solvent) that I’d just remove it.

[ketchito]

Could you make a test removing Plantapon SF? The amphoacetate there is an amphoteric surfactant, which at low pH, can behave as a cationic, giving that you’re below its pKa (which I didn’t check, but the test is still worth to be done).

[ketchito]

How are you mixing your acrylates (type of mixer, time and speed)?

[ketchito]

I have a trick: keep a high temperature during the whole emulsion process (75-80°C)…then, keep that same temperature for 10-15 extra minutes, but lower the mixing speen at 100-200 rpm (this will help remove most of the foam).

[ketchito]

You can use Carbopol 674: https://www.ulprospector.com/es/la/Cleaners/Detail/11384/35242/Carbopol-674-Polymer?doc=1173493&st=20&bplogin=success

ulprospector.com

Carbopol® 674 Polymer por Lubrizol - Productos de Limpieza, Domésticos, de Marca e Industriales

Carbopol® 674 polymer is a lightly crosslinked polyacrylic acid polymer powder. This polymer provides suspension at low product viscosity and improves f...

[ketchito]

You can check this thread on the topic:

https://chemistscorner.com/cosmeticsciencetalk/discussion/polar-value-of-oils-and-other-lipids/

chemistscorner.com

Polar Value of Oils and Other Lipids - Chemists Corner

Hi,Are there books or resources on polar values of oils and other lipids (other than the 2 articles on free patent) please?Following my last post…

[ketchito]

Chances are some oils and waxes are not compatible (different polarity can impact miscibility when mixed), so you better check that before. A non-ionic surfactant like the polysorbate you have is more useful when there’s water present, because it acts better in a protic media.

[ketchito]

Let’s put it this way, if that formula was an artery, not even plaques would clog it 🙂

There are several papers and books on the effect of both inorganic salts and CAPB to build viscosity of different anionic surfactants, but since you don’t have any anionic, they are useless.

Both Aloe Vera and Glycerin are useless in a cleansing product…not only they impair viscosity and foam without any real benefit, they increase the contamination risk of your formula. For sure the preservative you have will be overwhelmed by them.

[ketchito]

Can you make a sample without glycerine?

[ketchito]

Chances are your BK is binding to you dye (anionic), and when you add your acid thickener, your BK binds to that one instead and releases your dye (that’s why you see that color change). I remember these products use anionic surfactants instead, but to confirm, make a sample without BK.

[ketchito]

You might have just made a buffer yourself. If you managed to neutralize half of you acetic acid for instance, then you might have created a 4.5 pH buffer. The frst reading you had at around 6 is the free sodium hydroxide, because your system didn’t reach equilibrium. Working with that amount of acids is very hard indeed. I’d just theoretically find the amount of NaOH to make a pH 6 buffer, and use that as a starting point…but that means you’ll have to consume quite some NaOH. As a side note, your preservative actually has a chelant (the organic acid, but it’s just a very poor one), and In fact, more than a preservative, it’s a booster. Please use a more robust preservative system. Or get rid of the peptide (not doing anything really) and embrace benefit yourself from the low pH of your system (4.5 is OK for your type of product, which would make it possible to work with many preservatives).

[ketchito]

There are actually few studies using low pH formulas to improve hair properties. Keep also in mind that while water wets hair, there’s dilution and an increasing raise in pH until the solution has the same pH of water, so no change on skin. A different story is the lipid removal from surfactants.

[ketchito]

I wouldn’t rely on citric acid as a chelant, since you don’t have free electrons to interact with metal ions (which you have in citrates); rather, you have protonated groups that at most have a dipole (a ion-dipole can be feasible, but metal ions would compete with hydrogen bonds).

[ketchito]

The first thing to know is that glyceryl stearate is not a soap (like sodium stearate), but an ester.

Now, skin “acid mantle” is a semi-solid (with crystalline domains), the same as creams that are usually applied on the skin. That makes the concept of pH less relevant as opposed to liquid solutions, so I wouldn’t worry that much. Perhaps the pH range for this emulsifier has more to do with the risk of hydrolisys during product’s shelf life.

[ketchito]

Proposición 65 is not a science based document. The risk comes because of secondary amines, which are impurities from the quaternization process (secondary amines are present in most cationics, at very low levels). Now, secondary amines themselves are not harmful, it’s only when they’re converted into nitrosamines. For that to happen, you need a nitrosating agent, which current cosmetics barely have. Also, you can minimize the risk by having an acidic pH in your formula (this neutralizes amines).

[ketchito]

I think you better find another chamber to do the stability. There might not be annything wrong with your formula, just a very unrealistic stability temperatura.

[ketchito]

Just as an experiment, remove your coco-glycoside and increase Lamesot PO65 up to 5% (as is). I see on the manufacturer’s website that tests are done at the highest recommended dose, and the Garnier product actually has it at high level, so let’s see if the magic occurs at that dose. If positive, you can start dosing down until you find a confortable level.