soap-based facial wash - Chemists Corner

Formulating

soap-based facial wash

Posted by crisbaysauli on September 22, 2014 at 5:34 am

Hey fellas…I need your two cents on this one.

I’m trying to do a soap-based facial wash using saponification. Ingredients for this product are as follows

Stearic acid

Myristic acid

Potassium hydroxide

Glycerine

SLES

Cocamidopropyl betaine

The goal is to have a cream-type facial wash. The problem is, I can’t get the foam and lather i want.

Can you help me?

crisbaysauli replied 9 years, 9 months ago 4 Members · 8 Replies
8 Replies

Chemist77

Member
September 22, 2014 at 6:06 am

1) Either replace saturated fatty acids with some unsaturated ones and check how they come out e.g. potassium oleate gives good lathering.
2) Or get a surfactant which works optimum at an alkaline pH around which a potassium stearate/myristate soap would generally be stable. As generally we see in shampoos (sulfate based) that they work good at acidic pH I think that if you get some surfactant which performs well in alkaline conditions, you might get some lead. I hope I am correct in my approach here.

3) Last but not the least, someone chips in a better suggestion.

Cheers
belassi

Member
September 25, 2014 at 2:19 pm

It appears to me that you are creating a natural potassium soap (KOH + myristic and stearic fatty acids) which will in itself have a glycerin content, so first, I’d remove the additional glycerine.

But then, you’re combining this with two synthetic surfactants, one of which is anionic and the other, amphoteric.

I don’t see any immediate reason why CAPB can’t be added, but the SLES isn’t going to work with an alkaline soap having a pH of around 10, I would guess.

I think you need first to decide if you want to base your facial wash on “natural” soap or on synthetic surfactants. For a “natural” soap you should follow the guidance that you can find in many soap forums; for a synthetic wash, check out Swift’s blog (swiftcraftymonkey) - SLES and CAPB make a starting point, to make it creamy you’ll need a pearlising agent.
vitalys

Member
September 25, 2014 at 10:22 pm

I’m sorry - there is no glycerin formation in this reaction: KOH + myristic and stearic acids.
Chemist77

Member
September 26, 2014 at 9:32 am

Anyway glycerin can be avoided here as it is a foam suppressant and brings the viscosity down and this has been repeated by many learned chemists here, in fact in a very recent discussion by @chemicalmatt and I would take his word pretty much seriously.
belassi

Member
September 26, 2014 at 2:31 pm

I don’t get this idea about glycerin suppressing foam or viscosity. I have just made two versions of my sulphate-free shampoo. One with 3% glycerin and one without. The one with glycerin has higher foam and viscosity than the one without. Also, natural (cold process) soap is full of glycerin and produces more foam than I can get with synthetic surfactants, generally.
crisbaysauli

Member
January 12, 2015 at 9:22 pm

@Belassi. Thank you for the information. I tried your suggestion and the following became my ingredient list

Stearic acid

Lauric acid

Myristic acid

Potassium hydroxide

PEG-150 distearate

Glycol distearate

Beeswax

Coca betaine

My problem now is, the cream formed appears bubbly, not smooth. Is this just a matter of mixing speed? Or do I need a vacuum pump to remove air in the mixing vessel?
belassi

Member
January 13, 2015 at 11:30 am

Well, it IS a soap, so you’re bound to get foaming when mixing. You’re implying that it is too thick for the air bubbles to migrate to the surface and disappear? That would be a production, not a formulation problem, I think.
crisbaysauli

Member
January 26, 2015 at 12:13 am

Thank you so much @Belassi!