[Pharma]

Increase. That’s why shampoo thickens with salt .

[Pharma]

1. No, the amount of molecules within the water/air interface is too small to change anything. Also, the used concentration is commonly way above CMC.

2. Once you mix two surfactant, the resultin apparent CMC is unknown. And, as said, most everyday situations deal with concentrations well above CMC.

3. Yes, both. Read a book.

4. Many. Read a book.

Recommended online literature: CLICK

[Pharma]

CMC is the concentration above which a surfactant is no longer soluble (and the water/air interface becomes saturated as a side-effect) but starts to form micelles. The CMC is the lowest concentration at which a surfactant actually behaves as surfactant and not just a dissolved compound (the amount at the water/air interface is actually not considered in ‘real’ CMC though several methods for the determination of CMC automatically/unwillingly include that effect as well). In case of SLS: If you use it below 185 mg/l, it won’t foam and it won’t clean. Sure, surface tension and wettability are already lower than plain water but that’s not enough for most applications. Even more, CMC is utterly useless in most everyday situations, especially in complex surfactant blends. There is however a tendency that surfactants with a low CMC perform better; it’s neither a direc correlation nor scientific in any regard, it’s just a trend when looking at commercially available surfactants.

CMC gives neither an indication on micelle size nor the number of molecules within a micelle. Again, the tendency is that lower CMC mean smaller micelles with less molecules per micelle (= aggregation number). These values also depend on the amount of added salt and other ingredients.

[Pharma]

By definition, COCOYL means coconut oil derived…

Cosmetics aren’t always too strict when it comes to naming products and hypothetically, there could be cocoyl whatever products which contain palm oil too… however, palm oil is a source for longer chained fatty acids and hence isn’t well suited to adulterate sodium cocoyl isethionate.

[Pharma]

Microformulation said:

This is not research.

We don’t know which serine protease is in that product, only that it’s genetically modified… Anyway, some serine proteases, especially keratinases, do digest keratin as has been published in Nature, PLOS ONE, and AJAS. They do not mention hair relaxing but rather hair removal… the difference of which, as we know from common chemical hair treatments, lies in concentration and duration. The step from no hair to different hair is really a short one .

Fun fact: Subtilisin, a serine protease, is commonly used in laundry detergents to remove protein stains and is a fodder additive for chicken (because of the same effect as Ronozyme: increasing digestible proteins), it also breaks down keratin (which you already know, now that you have read some real publications)… I wonder how long it would take until someone tried laundry detergent as hair relaxer if I posted this on TicToc as new life hack 🙂 .

[Pharma]

Microformulation said:

What is your emulsification system?

That oil phase composition results in solid droplets… all it takes is high sheer and a good enough thickener to keep them from creaming :smiley: .

Looking at it makes my eyes sore…

[Pharma]

Mica, especially synthetic and/or highly purified ones such as RonaFlair, shouldn’t pose any trouble.

[Pharma]

They’re not interchangeable and yes, you would have to know their degree of polymerisation. Short PEGs are liquid, long PEGs waxy, and very long ones hard like platics (which they are).

[Pharma]

What type of soap? Alkali soaps, due to their alkalinity, will be an issue in case of metabisulfite. Even ascorbic acid isn’t going to work as nicely due to chemical degradation. Phenolic and thiol antioxidants are really active at alkaline pH… that is, they work too well too fast…

[Pharma]

According to Chapter 4.12.2 of ‘Chemical and physical bevaviour of human hair’ by Clarence R. Robbins, hair relaxation is only permanent with a supercontraction of >5% which can not be achieved by a base. Disulfide reduction (using reducing agents or bases) and/or lanthionine formation are not enough for a really permanent relaxation whilst alpha-keratin denaturation is.

[Pharma]

There are other thiols emerging… as @Perry mentioned, most smell acrid and sulphurous, others are nearly without odour but are too expensive for cosmetic applications (dithiothreitol -> probably the best you can get, commonly used in research because it doesn’t alter the chemical structure beyond clean disulfide cleavage nor forms disulfide bonds with cysteine as do most others).

[Pharma]

It’s just a matter of taste, they’re synonyms. Some industries/applications/products call it this, others that way.

[Pharma]

You do the maths:

- Both are huge molecules with a ‘tine’ amount of bound ascorbic acid.

- The branched alkyl chains make enzymatic cleavage difficult -> biological activation is not that easy.

- They’re highly lipophilic and keep them stuck in the upper SC in the lipophilic compartment (activating enzymes are in the aqueous compartments).

- They’re more expensive than plain ascorbic acid and a lot more expensive on an equimolar scale (same amount of ascorbic acid and not same weight).

[Pharma]

@DaveStone It should. Like: No-lye generelly contains other bases and does work in a similar way (ORS is alkaline). No, the effect using a base is not permanent (it’s mostly just swelling) and hair structure reverts back after several weeks. Using a thioglycolate based relaxer is more effective because it does change the hair’s structure (alkaline versions can too… when left on too long and the hair gets damaged beyond repair).

All in that text .

[Pharma]

The isopalmityl and tetrahexyldecyl residues aren’t chemically identical and are even in cosmetics usually differenciated. However, cosmetics does not really adhere to classical organic chemistry and sees things a little too lax ;( .

Anyway, tetrahexyldecyl chains are derived from a Guerbert alcohol (even in cosmetics) whilst isopalmityl moieties are isomerised palmityl chains which comprise a mixture of linear hydrocarbon chains with several methyl branches (true ‘isopalmityl’ is just the main constituent and Guerbet alcohol derivatives do not occur).

Both tetraesters of ascorbic acid are in use, officially under two different INCI names. Distinguishing might not be too easy just by looking at them.

[Pharma]

Find your answers HERE.

[Pharma]

You should send out samples, that would really help.

You’re happy with your product and it works (assuming stability testing comes out fine) which means it’s a good product when neglecting consumers and marketing. Why do you want changes?

I would have done it differently…. mostly for the reason I prefer less synthetic ingredients and like plant extracts (because I like plants, not because cosmetic plant extracts would do much).

Things you could try: Swap propylene glycol for a non-polyol humectant such as betaine. Use a silicone polymer/film former/elastomer instead of dimethicone.

[Pharma]

@helenhelen Thanks! Okay, it’s about 10% each potassium jojobate and jojoba alcohols. Meaning, HLB of potassium jojobate (mostly potassium gondoate) can be calculated (something below 20) and it would count as emulsifier whilst the fatty alcohols (mostly a mixture of eicosenol and docosenol) should have an HLB requirement of somewere above 13 and count to the oil phase.

[Pharma]

Do you know it’s chemical composition? I don’t but wonder…

[Pharma]

Oh, behenyl alcohol. I would dare saying that this shouldn’t have a negative impact either (it’s high melting). MM feels nice but due to its lower melting point compared to other ester waxes doesn’t have that much of an effect when comparing different similar ingredients. The difference only comes into play when comparing w/o with w/.

[Pharma]

Swapping behenyl behenate with myristyl myristate is likely going to increase ‘grease’ and only with luck play time.

Coco caprate/caprylate should have a short enough play time whilst octyl palmitate is used to increase play time. Me, I woldn’t do a swap but just reduce octyl palmitate content (and probably also reduce the natural oils…).

Maybe increase fatty alcohols a bit.

[Pharma]

Both phenomena are not bound to petrolatum but anything with such properties. You can achieve occlusion with a cling film. The insolubility or ‘anti-solvent’ part highly depends on the ingredient and its solubility and insolubility in different solvents and its solubility in skin.

[Pharma]

That citation only cites a poster (number FC 02-06) presented at the 22nd World Congress of Dermatology, Seoul, Korea, 2011.

Can’t find the poster online but you can find another publication by those autors HERE. BTW they are either part of, affiliated with, or financed by P&G who also holds a patent regarding SDA & niacinamide for said claim.

[Pharma]

Occlusion and insolubility

[Pharma]

For nail and cuticle creams, a longer play time is okay to get that cream really everywhere but like the previous posts, when working (job or garden) or to ‘cure’ too much hand disinfection, a fast job (1 minute already feels long then) is what I like and what suffices.