[Gunther]

@jeremien so that means that SLES is still viscous at 30%, so you’d need to dilute it down to 27% or less for it to become water-thin ?

[Gunther]

@Soaper_Babe just for a twist, the next time you can try either buying distilled fatty acids, or hydrolyzing oils to get them with acid (be careful) 
and neutralizing the free fatty acids with Ammonia instead of Sodium or Potassium hydroxide to get Ammonium soaps.
(You may wish to do so in a closed bottle, to avoid ammonia fumes).

I just tried that with Oleic acid and it feels so much better than the Sodium salt, and pH ain’t as high.

[Gunther]

@Vnnil IMO Sodium hydroxide scares people away, even if placed way down in the list of ingredients.

@Microformulation the Lubrizol paper mentions that Arginine can be used to neutralize carbopol
It would be interesting to try to see if skin feel gets any better.
I recall Ajinomoto studies that suggest that Arginine improves almost everything.

[Gunther]

For pump sprays you need it to be water-thin
carbomer will thicken it, so it won’t get atomized by the pump.

IMO the best, mild hold, quick dry spray
is just a silicone dissolved in cyclomethicone, diluted enough to make it water thin
but that won’t likely be considered natural.

[Gunther]

You can try substituting exotic oils for plain ones that don’t usually cause allergy, to see if it helps.

[Gunther]

Perhaps it is because of marketing soaps as natural?

Human saliva is naturally occurring
mucus = natural
sneeze and cough fluids = natural
hair = natural
dead skin cells = natural
sweat = natural
floor microbes = natural

Sorry, I couldn’t resist 

[Gunther]

Try with water replacing honey to see if it makes any difference
and try adding a silicone, preferably a water dispersible silicone for ease of formulating.

Is HEC intended as a thickener?

[Gunther]

Can you use PEG-150 distearate along carbopol (to thicken sulfate-free surfactant formulations, CAPB+glucoside), and are there any advantages or disadvantages in doing so?

[Gunther]

@Belassi did you use gel networks in your products, or did further experimentation with them?

[Gunther]

@ngarayeva001 did you use emulsifiers to hold oils in solution?
Did the glucosides act as emulsifiers in that formula?

May I ask why do you prefer PEG-150 to carbopol?

[Gunther]

@ngarayeva001 

Does glycerin has to be that high? Doesn’t that leave a sticky afterfeel?

Did Xanthan gum leave a slimy feel?
Have you tried this formula with other thickeners, like Guar gum (plain guar gum, not the cationic one), or Carbopol?

[Gunther]

@ngarayeva001
Is that 10% active Cocamidopropylbetaine?
or 10% as supplied ( about 3% active )

Is almond oil (or any other replacement oil) a must? can you remove oils?

[Gunther]

@HairmanPhd sorry if this sound obvious but can you please clarify if the product is intended to be applied on hair or skin?

@Bobzchemist do you know of a volatile organosilicone suitable for replacing cyclomethicone?

@chemicalmatt thanks for mentioning Finsolv TN.

[Gunther]

Use only FDA approved colorants. They usually have a number after them.

You can use a pearlizer. You may need an opacifier as well.

It looks like people perceive white, pearl and pale green as more conditioning and maybe even more “natural” than other colors.

@Chemist77 can you use cetyl or cetearyl alcohol as opacifier in a shampoo? or it will just slowly sink to the bottom?

[Gunther]

There’s no clear evidence that soap really benefits from added glycerin 
and there’s evidence that glycerin hinders foam.

IMO the best way to improve saponified soap skin feel
is to try to make its pH not as strongly alkaline
Neutralizing fatty acids, a simpler reaction than saponification, may allow for a closer control of Sodium hydroxide
albeit hot process soap already reduces excess NaOH compared to cold process.

[Gunther]

To get the average dispensed volume you trigger the pump several times

i.e. 20, 50, 100 times

pour liquid in a accurate graduated cylinder, measure it and divide by the number of sprays.

https://en.wikipedia.org/wiki/Graduated_cylinder

Now to determine the variation

you’ll need accurate equipment

IMO the best way to do it, without spending too much is to get a microliter syringe.

https://www.hamiltoncompany.com/products/syringes-and-needles/general-syringes/microliter-syringes

[Gunther]

Interesting
I always wondered if you can make an emulsifier out of CETAC + fatty alcohol.

@DAS Do you know why Croda used cetyl alcohol in their BTMS and not cetearyl alcohol instead?

[Gunther]

While there are some (low quality) studies that suggest so,
they may not work in real life

http://www.regrowth.com/hair-loss-forums/topic/topical-garlic-study/
This studies alopecia areata, which may not work for general baldness.

Interestingly a Yokohama university study used dimethylpolysiloxane (dimethicone) to grow culture hair follicles:

Practical hair regeneration technology

Researchers develop a method for large-scale preparation of hair producing tissues

Date:February 1, 2018

Source:Yokohama National University

Summary:

Researchers have developed a method for the mass preparation of cellular aggregates, also known as ‘hair follicle germs (HFGs)’, that may lead to a new treatment for hair loss.

Culture vessel for the mass preparation of hair follicle germs (above). Generated hairs on the back of a mouse (below).

Credit: Yokohama National University

Researchers have developed a method for the mass preparation of cellular aggregates, also known as ‘hair follicle germs (HFGs)’, that may lead to a new treatment for hair loss.

Although hair loss is not life-threatening, it troubles a substantial number of individuals all over the world, particularly in aging societies. Hair regenerative medicine has emerged as a new therapy to combat the problem. The therapy involves regenerating hair follicles, the tiny organs that grow and sustain hair. One of the more challenging obstacles to hair regenerative medicine has been the preparation of hair follicle germs, the reproductive source of hair follicles, on a large scale.

The paper, published in the journal Biomaterials, reports the successful preparation of up to 5000 HFGs simultaneously, and reports new hair growth from the HFGs after transplantation into mice.

“The key for the mass production of HFGs was a choice of substrate materials for culture vessel,” says the corresponding author Junji Fukuda, Professor, Yokohama National University. “We used oxygen-permeable dimethylpolysiloxane (PDMS) at the bottom of culture vessel, and it worked very well.”

The research group further evaluated the feasibility of this method by transferring the prepared HFGs from a fabricated approximately 300-microwell array, called “HFG chip,” to generate hair follicles and hairs on the mouse body. The group confirmed black hair generation at both the back and scalp transplantation sites. The regenerated hair exhibited the typical hair cycle of murine hair.

“This simple method is very robust and promising. We hope that this technique will improve human hair regenerative therapy to treat hair loss such as androgenic alopecia,” adds Fukuda. “In fact, we have preliminary data that suggests human HFG formation using human keratinocytes and dermal papilla cells.”

Story Source:

Materials provided by Yokohama National University. Note: Content may be edited for style and length.

---

Journal Reference:

1. Tatsuto Kageyama, Chisa Yoshimura, Dina Myasnikova, Ken Kataoka, Tadashi Nittami, Shoji Maruo, Junji Fukuda. Spontaneous hair follicle germ (HFG) formation in vitro, enabling the large-scale production of HFGs for regenerative medicine. Biomaterials, 2018; 154: 291 DOI: 10.1016/j.biomaterials.2017.10.056

https://www.sciencedaily.com/releases/2018/02/180201142853.htm

[Gunther]

You can make fairly good soaps using all fatty acids and no oils the following way:

Phase A
Pour
53.93% Palm Oil fatty acids
13.48 Palm Kernel fatty acids
Heat to melt in a double boiler

Phase B
Pour 
5.39% Sodium hydroxide
10.78% demineralized or distilled water
for a concentrated Sodium hydroxide solution

Pour phase B slowly on phase A, it takes 20 minutes to pour it all
keep warm, and stir carefully.

Phase C
Pour
10.78% demineralized or distilled water
5.39% Sodium hydroxide
0.01 - 0.07 % EDTA Tetrasodium
0.17% Sodium chloride

Pour phase C slowly on phase A+B it takes 20 minutes to pour it all

keep warm, and stir carefully.

Then you can air dry, or press the final soap to eliminate excess moisture.

This should cut costs since fatty acids are cheaper than oils.

[Gunther]

In short, there are no good, really natural surfactants.

1. There are some saponins occuring in plants, they are truly natural since they exists in plants
but they foam badly, and may be irritating.
They have been used by native people to wash clothes.
i.e. soapberry tree, California soaproot and the soapwort plants

2. Saponifying vegetable oils with lye
While oils are natural, the process is manmade so not truly natural.
You can even get Potassium hydroxide from wood ashes, that some people perceive as more natural.
The big problem is that such soaps need an alkaline pH to avoid reverting back to their free fatty acids.
Their solubility in water is a big problem too
https://link.springer.com/article/10.1007%2FBF02645899

3. BS “naturals”
like glucosides
even if made out of natural ingredients like glucose,
in the manufacture process they often use harmful solvents that may remain in trace amounts in the final product.
Glucosides are hard to thicken, and don’t clean or foam as well as synthetics.

[Gunther]

You’ll need to dig into wax specifications (ask the suppliers for them).
waxes are mixtures, not single substances
So both the wax source and the hydrogenation degree need to be similar, to get similar results.

Maybe Carbon lengths, insaturation degree, iodine values and other specs can guide you towards finding a suitable replacement.
And of course, there’s no replacement for experimentation.

[Gunther]

You can convert Disodium into Tetrasodium EDTA yourself

If I’m not mistaken,
for every  372.24 g Disodium EDTA
https://www.sigmaaldrich.com/catalog/product/usp/1233009?lang=en&region=US

add 2 moles Sodium hydroxide = 80.0 g
https://www.sigmaaldrich.com/catalog/product/sigald/s8045?lang=en&region=US

you’d get 
380.17g Tetrasodium EDTA plus extra water from the reaction
https://www.sigmaaldrich.com/catalog/product/sial/03701?lang=en&region=US

As for etidronate
try a local pharmaceutical ingredients suppliers
or you’ll need to import it yourself.

[Gunther]

May I ask what happened with higher DFAs?

What DFAs did you use?
Do you know the originating plant, carbon length or insaturation degree?

Can you buy both palm oil and palm kernel oil fatty acids from them?
For best results you’d need a mixture of them.
Just one or the other may not work properly.

[Gunther]

pH 11 seems excessive. Maybe you’re using too much Sodium hydroxide?

Do you use both PKO oil, and PK fatty acids in making the soap?
thus saponifying PKO, with some additional hydroxide to neutralize the extra fatty acids added?

How do oil and fatty acids costs compare to each other?
May I ask the oil and fatty acids percentage in the formula?

[Gunther]

The effect of urea and taurine as hydrophilic penetration enhancers on stratum corneum lipid models

Muellera1J.S.L.Oliveirab1R.Barkerc2M.TrappdA.SchroeteraG.BrezesinskibR.H.H.Neuberta

Highlights

•

Effects of urea and taurine on SC lipid structure are studied deploying a wide panoply of techniques in 2D/3D model systems.

•

Urea and taurine do not fluidize the very rigid SC lipid structure.

•

Under special conditions, urea and taurine are able to form pore-like structures in the SC lipid membrane.

•

The penetration enhancement effect of urea and taurine in the SC must be related with the corneocytes.

Abstract

To optimize transdermal application of drugs, the barrier function of the skin, especially the stratum corneum (SC), needs to be reduced reversibly. For this purpose, penetration enhancers like urea or taurine are applied. Until now, it is unclear if this penetration enhancement is caused by an interaction with the SC lipid matrix or related to effects within the corneocytes. Therefore, the effects of both hydrophilic enhancers on SC models with different dimensionality, ranging from monolayers to multilayers, have been investigated in this study. Many sophisticated methods were applied to ascertain the mode of action of both substances on a molecular scale. The experiments reveal that there is no specific interaction when 10% urea or 5% taurine solutions are added to the SC model systems. No additional water uptake in the head group region and no decrease of the lipid chain packing density have been observed. Consequently, we suppose that the penetration enhancing effect of both substances might be based on the introduction of large amounts of water into the corneocytes, caused by the enormous water binding capacity of urea and a resulting osmotic pressure in case of taurine.

https://www.sciencedirect.com/science/article/pii/S0005273616301845