[Pharma]

If you want to play on the safe side, go with stuff bacteria can’t digest, not just short fatty acid chains (which they could but don’t like because of membrane destabilising effects) and long fatty acid chains (which they can’t easily eat because of very poor water solubility). I’m thinking silicone and paraffin oils and silicone/PEG/PPG surfactants. Problem solved.

Although a surfactant is no longer a fatty acid (except for fatty acid salts), they may be metabolised (like triglycerides) by bacteria and there is reason to suspect that certain fatty acids such as oleic acid may favour growth of certain bacteria even if covalently linked. However, simply demonising 99.9% of all biologically relevant fatty acids is utterly stupid because your skin is made of a good portion of exactly that.

On the other hand, you would have to ban all triglycerides and most other oils from your creams and, as said, be left with silicones and hydrocarbons.

[Pharma]

Phenol is a chemical prohibited in most countries whereas polyphenols simply contain subunits with structural similarities with phenol but have no biologically identical behaviour. I don’t know what you exactly mean with ‘suffering from phenol intolerance’. If it’s a real intolerance for phenol, then you’re safe with any natural product.

[Pharma]

Why don’t you just buy Differin gel/cream for 1/10 of what you’re going to pay for an equal amount of adapalene (BTW Sigma does only ship to companies, not private persons and has a minimal order fee which isn’t that obvious when reading the terms & conditions).

[Pharma]

Belassi said:

the original manufacturer or a China source.

At least in Europe, adapalene is a drug and like most API (active pharmaceutical ingredient), the original manufacturer IS in China, just the ‘cream maker’ may be local and certainly won’t sell APIs (they may donate small quantities to research & universities). The reason for the high Sigma price is that it’s a small quantity at a very high purity, not that mush cosmetic grade. If you’re looking for APIs, they are relatively cheap, require re-testing and sometimes re-purification, and a liaison in China or a visit to an API congress. They basically sell to everyone even if patent rights prohibit you from actually using what you buy.

[Pharma]

Ups… did translate/interpret OP’s phrase the wrong way… she/he is looking for something outside the C12-C24 range. And that more or less leaves her/him with C10/decyl or such based on octacosanol or triacontanol such as octacontyl sulfate or triacontyl phosphate (which, to my knowledge, do only exist in patents and as research chemicals). Or rhamnolipids and trehalolipids might work (they’re for example based on two C8 and are often not standard fatty acids but derivatives) .

Good reading: Renewable Surfactants for Biochemical Applications and Nanotechnology by Sarah Le Guenic et al.

[Pharma]

Funky? Lice solution? Dunno how that smells…

Funky sounds like dank but this here isn’t a weed forum, so… and our lice products don’t contain benzyl alcohol (lucky us).

Hence, could you describe the aroma better because I have no clue what you smell?

BTW salicylic acid and glycerin have no odour and sorbic acid may smell unpleasant upon degradation but IMHO it’s not a strong odour.

[Pharma]

Decyl glucoside is often a mixture with a higher % of decanol (still likely less than 50%) whereas caprylyl/capryl glucoside is rich in octanol and decanol but as well doesn’t contain just these two.

The chains of emulsifiers are most commonly fatty acids whereas many common surfactants contain fatty alcohols instead. These are usually derived from fatty acids (anionics such as alkyl sulfates, alkylether sulfates, sulfoacetates, most synthetic nonionics, and glucosides). Performance and feel are +/- identical between ester and ether/acetal groups. Quaternary ammonium soaps usually don’t contain either but are made out of ‘pure’ hydrocarbon chains linked to the ammonium nitrogen via C-N bonds. Also, alkyl- and alkylbenzenesulfonates don’t contain fatty acids/alcohols but ‘pure’ hydrocarbons linked in this case to the sulphur atom via C-S bonds.

Is there any reason why you don’t want anything fatty acid derived? And what’s the reason behind the C12-C24? Why not C10? Nearly all commercial surfactants have chain lengths between C10 and ~C24 because shorter than C10 turns them too hydrophilic to function as surfactant whereas very long chains would make them very powerful surfactants weren’t it for the fact that these are usually no longer soluble in either phase and have too high melting points (extended surfactants are an exception but these are not used in cosmetics).

Honestly, to me you sound like haveing no real clue of surfactants… (no offence!)

[Pharma]

What do you smell: Floral or bitter almonds/marzipan?

Floral would be benzyl alcohol in its pure form and can be masked with other (floral) perfumes whereas ‘marzipan’ comes from the oxidation product benzaldehyde. This one is difficult to mask. Benzaldehyde increases with age of your product or the preservative, may be generated on skin upon UV irradiation… You could buy new product (might help but our noses are so sensitive to it that even fresh product quickly develops that flavour), stabilise your lotion with a good antioxidant if it only appears after production, add a UV filter if it only happens on sun exposed skin, or add some almond oil and call your product ‘Pure Almond’ (seriously!).

[Pharma]

Ditch castor oil, that stuff feels terrible. Depending on hair type, reduce hemp seed oil and/or shea butter… but honestly, I’d safe the money and use the oils (given that my hair would tolerate them) and use them as a leaf in and not under the shower. You could add maybe 0.5-1% oils, more seems unreasonable and ‘kills’ the emulsifiers.

You could add some more fatty alcohol, like 20% instead of 2% .

There is no reason why you should add glycerol to a rinse off.

[Pharma]

QAC = quaternary ammonium compound = ‘invert soap’ = cationic surfactant/emulsifier = main ingredient in hair conditioners apart from fatty alcohols.

Butylene aka butene is a propellent at best… you mean butylene glycol, I suppose. Dunno… you’ll have to run both against each other.

Evonik has nice things though many of their ‘active’ ingredient blends are more shine than anything else. Given that they are already blends, they’re made so you don’t have to mix pure compounds yourself . I’d guess if 1 or 2 such blends don’t suffice, then these blends are useless. Me, I prefer pure stuff and mixing everything myself. But that’s just me with my hobbies…

[Pharma]

1. What kind of product is it? A conditioner? More oil is likely to to make it ‘creamier/richer’ and quite often also thicker (unless it breaks because of too much oil). On the other hand, your hair might get oilier…

2. Because emulsifiers are expensive and often regarded as ‘bad’, you opt for the minimal requirement. You add more if emulsion isn’t stable (especially if it was before you added more oil phase). The emulsifier forms a molecular ‘shell’ around oil (or water) droplets which keeps them emulsified. More droplets mean more surface to cover = more emulsifier needed. Some emulsifiers (liquid crystal network aka lamellar structure emulsifiers) tend to give more substance if more is added. Some won’t have much effect by themselves and others will reduce viscosity because more emulsifier means more droplets and with the same amount of oil, this results in smaller droplets. Try it out.

3. Link? Read books about the basics and also manufacturers recommendations. Cetyl and cetearyl alcohol give more substance if you have a lamellar structure. BTMS is an QAC and you add as much you need for the desired effect.

Why and what ain’t usually very scientific in the cosmetics field. Most is hearsay, tradition, preference, availability, and personal experience. Sometimes it is an advantage to use more than one, other times it doesn’t.

You’ll have to try both to see which one you personally like better. How you understand: Read books and try stuff.

[Pharma]

12% ethanol will keep most but not all germs from growing and it won’t kill any.

The 2% glycerol are, at that concentration, bug food at best whereas zinc sulfate at 1% hampers microbial growth (likely not of all but of many).

The 0.4% phenoxyethanol should put your product in a safe spot.

Is it a spray? Else, I concur with @chemicalmatt: Why a surfactant?

BTW most scientific and most older literature uses the term nonionic surfactant for PEG derivatives. The inhibitory effect of modern nonionics on preservatives is largely unknown. Given that you use a surfactant without any oil phase increases the chances for inactivation of phenoxyethanol, no matter which type of surfactant you use. However, the more ethanol and glycerol you add, the smaller that chance gets.

[Pharma]

deneuxben said:

…

@Pharma Which one worked best in a solid soap bar ? pretty please ?

I am not equipped with something to measure RH unfortunately. If I understand your point about starch, the finer the grain is, the more susceptible it is to adsorb water (more surface area)

So far I have stayed away from clays because of their reputation to be hard to preserve. But it seems to me that you are implying this would be the best choice here (less batch to batch variation) ?

…

I don’t know, I’m not a soap guy . Else, I’d already told you.

RH just requires a cheap hygrometer and a jar. But as said, with those ingredients absolutely pointless.

The finder starch grains are, the more water they will adsorb, correct.

And yes, clays are hard to preserve and no, I’m not implying that they were the best choice. What I said is that they have a very large surface and will therefore adsorb more moisture than starch. As said, I’m not a soap guy and can’t tell you which product works best (or worst). All I’m saying is that these ingredients aren’t hygroscopic but they will take up some of the moisture within the soap. However, they are not very likely to have the soap ‘suck up’ water from the environment like hygroscopic ingredients would.

[Pharma]

deneuxben said:

…Hence, I would like to know how hygroscopic are these material ? Is there a way to find this out ? My objective would be then to select the one that is least hygroscopic…

Maybe not only the material counts but also its particule size ?

• zea mays starch
• avena sativa kernal flour (50 microns)
• Distarch phosphate (modified rice starch)
• arrow root powder
• hydrolyzed pea protein (90% protein)
• illite (green or red clay)
• kaolin (white clay)
• Rhassoul, maroccan lava clay

…

From a scientific point of view, these materials are not hygroscopic except for pea protein if highly hydrolysed.

And yes, there is a way to find out how hygroscopic an ingredient is: measuring RH.

In your case, all ingredients (especially the clays) will have high batch-to-batch variation and adsorb water to some extent. This ‘extent’ depends mainly on surface area (in case of starches/flours, this depends on particle size whereas pore size predominates in clays) and correlates directly with RH (or surrounding water if used in a soap bar).

The effect of water adsorption can go either way -> maybe just ask ‘Which one works best in a solid soap bar’ .

[Pharma]

Depends probably on the regulations of the country you’re selling.

Here around, if it’s known to be present, then it has to be listed. Although, this is likely ignored by some.

[Pharma]

helenhelen said:

…
In my case, I believe soaping is coming from polar oils (most vegetable oils are polar while hydrocarbons like mineral oil are non-polar) being in an alkaline environment (e.g. barrier-compromised skin, or skin just out of the bath)… literally saponifying and turning into soap….

Dimethicone is non-polar. I wonder if the reason it works so well at eradicating soaping is that it creates a barrier between the polar oil molecules and the alkaline environment, preventing the polar oil from reacting with the alkali and saponifying. …
The other thing I’ve heard helps with preventing soaping is adding a low HLB, non-ionic co-emulsifier to reduce saponification. This is why glyceryl stearate (HLB 3. is recommended alongside Olivem 1000.

Anyway, that’s my rambling thoughts typed up with a toddler on my lap… so this is probably full of mistakes.

Blunt answer: yes, it is full of mistakes. See, if your skin were alkaline enough to saponify triglycerides ON your skin, it would be alkaline enough to saponify triglycerides IN your skin turning YOU entirely into a giant junk of soap (with a saponified toddler on what once was your lap). BTW the surface of healthy skin is supposed to be slightly acidic.

Dimethicone is an anti-foaming agent due to its ‘ultra-lipophilicity’ (it’s oilier than oil). This shifts the equilibrium of the emulsifier. The latter is a surfactant and surfactants soap aka foam if mixed with air and a liquid or emulsify if mixed with two liquids (i.e. water and oil). Dimethicone simply ‘uses up’ the emulsifier crashing it’s low surface tension and destroying foam/emulsion. That’s also the main reason why silicones require silicone emulsifiers to form emulsions.

Olivem 1000 is something entirely different. The perception of soaping is not caused by the same effect. Here, I don’t know how it comes to ‘soaping’ (it’s not a chemical reaction, though!). Adding glyceryl stearate boosts its potential to build a lamellar structure aka liquid crystal network. I suppose it’s because the better that network, the lower chances become that the emulsion upon application (which means high sheer stress and water evaporation) turns from lamellar to hexagonal or similar (which would then follow the same rules as in the above case).

[Pharma]

Graillotion said:

Every re-packer out there sells an emulsifier with the following INCI: Glyceryl Stearate (and) PEG 100 Stearate.

Question…. Is it safe to assume these are all the same ratio?  (And will therefore preform the same?)  I am guessing these all originate from just 2-3 manufacturers. (maybe less.)

Emulsifier 165 is produced by several manufacturers and hence, proportions aren’t the same for everyone. However, if you know the manufacturer, check his pure glyceryl stearate and PEG-100 stearate (should they A: have both in stock and B: use the same glyceryl stearate for the 165 blend -> check MSDS). With the given HLB values of all three, it’s possible to get an approximate estimate of the used proportions.

Else, run an HLB or better yet an HLD scan to compare different batches.

[Pharma]

africanbug said:

thank you @Pharma, can I use the glycerine with SS for the d phase? sorry for my ignorance, I’ve not tried d phase emulsions before,,

You more or less INEVITABLY HAVE TO USE glycerol for d phase emulsification .

Regarding a question further up concerning to which phase an emulsifier should be added. Apart from pure liquid crystal emulsifiers (which are, from a physical point of view, usually VERY chaotic and unpredictable), the perfect emulsifier would be added to the interphase (that’s the super fine surface between the two phases). Alas, most cosmetic emulsifiers are far from perfect… D phase emulsification is therefore the closest one gets to adding it to the interphase.

Scientifically (which isn’t always very practical), there’s a bunch of rules and physical laws dictating the better phase (if the interface isn’t an option)… there is no definite answer and all depends on everything… and it boils down to what science wants to prevent: trial and error… more or less ‘the usual everyday routine when creating emulsions’. It could be a different, better world if one were for example to use HLD instead of HLB (HLB sucks and doesn’t really work other than predicting if it’s going to be rather w/o or o/w). As a current example: Olivem 900 is sorbitan olivate with an HLB of 4.7 and Olivem 1000 is cetearyl olivate (a wax which doesn’t have an HLB value) and sorbitan olivate and yet, it has an HLB of 8-9. Either someone is cheating and/or HLB is arbitrary.

[Pharma]

Don’t whisk and use Bamix fully immersed so there’s no air getting sucked into your emulsion.

Or try d phase emulsion.

[Pharma]

I had a customer once who didn’t want to buy a product because it contained alcohol: phenoxyethanol. She wasn’t offended by the presence of a preservative but ugh, ethanol is killing her skin. Can’t argue with that…

[Pharma]

Use search bar, it’s an old topic.

Clinically (proven), non are drying. Due to wrong handling, ethanol and propanol isomers are considered drying by consumers.

Fatty alcohols have about as much in common with the alcohols you’re referring to than other ‘alcohols’ in a chemical sense such as sugars or glycerol.

[Pharma]

blackbird said:

…an organic cream cleanser…

…glyceryl stearate citrate, could I swap this for cithrol 10GTIS . Iknow they are both anionic…

…Aloe vera juice, propanediol, xanthan gum, cetearyl alcohol, cetearyl glucoside, caprylic/capric triglycerides, evening primrose oil, gluconolactone, sodium benzoate, bergamot, geranium, rosemary essential oils, pomegranate enzymes, and tocopherols…

- Your product ain’t organic. It’s based on ingredients from renewable resources and probably Natrue or Cosmos approved (as natural, not organic).

- Cithrol 10GTIS is a non-ionic PEG derivative -> neither organic nor natural, glyceryl stearate citrate is a blend of non-ionic and anionic. It’s far less effective in a cleaning product than Cithrol 10GTIS (or is it something like a pore-minimising city-smog ‘cleaning’ leave-on detox cream?).

- IMHO your product is insufficiently preserved. You would have to check pH to guarantee a low enough pH but even then, it’s susceptible to moulds.

- Agree with @@helenhelen. Alexmo is a top DIY repacker.

[Pharma]

My guess would also be on too much shear. It’s a common issue with w/o.

[Pharma]

Coconut milk is not milk (it may, however, look white like milk and be used as vegan milk alternative), milk is from cows .

[Pharma]

Cafe33 said:

…They claim there is a fire retardant of some kind.

Fire retardant? Hmm… water comes to mind 🙂 …