[Pharma]

SSL would be a great partner for polyglyceryl esters. Maybe substitute 1/5 or so with it? Also, SSL works great in conjunction with fatty alcohols -> triple combinations (or such also including glyceryl monoesters) are frequently used to obtain lamellar phases. The job of SSL in there is mostly that of an anionic emulsifier which stabilises the formulation (electrostatic repulsion).

The question about ‘better emulsifiers’ can not be answered for several reasons (as you should know when reading older posts here on the forum).

[Pharma]

The problem with HCl is that it comes along with a lot of water. You would have to use dry HCl gas and that’s not practical. HCl would work (good enough solubility in solvents and oils) but is usually not used because of those limitations (either water or gas). Remember, your main enemy in esterifications and even more so trans-esterifications is water. Whatever it takes, avoid water! Standard sulfuric acid also contains water but H2SO4 is very hygroscopic and can be made water free and that’s one of the reasons for its use. However, sulfonic acids are prefered because they are easier to obtain in anhydrous form.

As mentioned before, focus on base catalysis: Easier, cheaper, and 10 to 100 times faster!

[Pharma]

Correct. Silicones do the trick if you are willing to use silicones. Me, I have a few silicones in stock but I try to get my way around them knowingly missing out on a great deal of astonishingly feeling formulations which can only be obtained with the aid of silicones.

IMHO people willing to use silicones might not be too much into the sustainable/green way of life and hence won’t use SSL because there are more draft formulations available without it than with it and the latter tend to use sustainable/green ingredients with all their possible disadvantages a silicone person would not dare risking.

[Pharma]

I don’t like it too much because it tends to make creams soaping .

[Pharma]

You can buy several catalysts (in powder form) of undisclosed composition.

Apart from that: Platinum on charcoal and other lab catalysts as well as powdered blood might not be practical, too expensive, and/or incompatible with hypochlorite… the rest you’ll have to google cause I’d have to do the same.

I don’t see any advantage of combining two gas producing reactions in one cleaning bomb. If you were to rely only on the reaction of acid with carbonate, then you’d have H2O2 left to help with the cleaning which you forfeit when adding yeast or iodide. Besides, all the fun of the latter reaction is that it, if done ‘right’, shoots out of the vessel, high up into the air .

[Pharma]

@chemicalmatt Right, that bomb combines two different strategies, one is CO2 formation due to reaction of citric acid with carbonate but the other one is the elephant’s toothpaste phenomenon created by an instant avalanche degradation reaction of H2O2 to oxygen. This reaction is not entirely catalysed by catalase and peroxidases (which would indeed be too slow) but mostly by stuff like iron ions within yeast which cause a sudden oxygen evolution.

I’m not sure if pH and/or bleach will mess up one or the other reaction to the point of disappointment.

However, too much acid will reduce the efficacy of bleach whilst helping with dissolution of deposits in the bin…

[Pharma]

Those phrases are marketing mumbo jumbo.

You could as well just saponify the oils and re-protonate the soap back to their acid forms. That’s how stearic and oleic acid are made.

Using enzymes, lipases in this case, is basically digesting triglycerides. As @chemicalmatt said, enzymes are more and more often used in standard chemical syntheses such as those required for the production of cosmetic raw materials. Enzymes have the advantage of a ‘cleaner’ product (higher selectivity and less side reactions = less colour/scent and less work-up needed), no/minimal heat requirement, and they act as highly specific catalysts.

Quality peptides (e.g. hydrolised silk proteins) are obtained with the aid of proteases (another type of enzyme), low grades (dark colour and smell of bouillon) are obtained traditionally using acids or bases.

Many amino acid based emulsifiers can only be produced with lipases. Many other things are obtained through fermentation instead of oldschool organic synthesis and are now being replaced with purified enzymes, xylite and ascorbic acid are such examples. There is nothing special about that Oleosoft-4 thingy except that its production is probably less ecological and less fast compared to traditional synthesis routes but maybe, just maybe, still contains the natural contaminants/goodies such as carotenoids, tocopherols, phytosterols, flavours, and other secondary metabolites which are usually lost during traditionally required refinement processes.

[Pharma]

@Perry Yeast is added as catalyst to kickstart decomposition of hydrogen peroxide (H2O2 is what’s originally used in the elephants toothpaste concoction and what’s created when dissolving sodium percarbonate in water). There are other, better, catalysts available such as potassium iodide.

[Pharma]

Read a book about emulsions or just use google, plenty of good explanations available there .

Using different phases is safe unless you had to increase concentration and or temperature to get there (I guess it wouldn’t be safe to use a phase which only formed at 90% SSL at 90°C LoL). Some of these phases are simply more appealing, more practical, and/or more stable than others.

[Pharma]

I’m sorry, they all won’t work. These are organic acids and they are simply not acidic enough to activate other carboxylic acids or esters.

Use calcium oxide or potassium carbonate to make biodiesel and use that to produce whatever you want . Although it’s two reaction steps, you still will be faster, a lot faster than with the acid route.

[Pharma]

There’s a difference in skin benefits after UV exposure, a very mild SPF of <6, and real sun protection.

Some natural compounds do absorb UV light but these are usually not or insufficiently present in oils except for carotenoids (which come with intense colour and a fairly poor absorption in the UV range). Coumaric and ferulic acid as well as many flavonoids would work better but these do not occur in oils. Carnauba wax contains cinnamic and related acid esters and does in fact absorb in the UV range… however, who wants to have a shell like a Smarties?

[Pharma]

Citric won’t work at all or at least not sufficiently enough.

Phosphoric acid has a bunch of drawbacks:

- It is a rather weak mineral acid if compared for example with HCl or H2SO4.

- Acid catalysis activates the acid or ester which means the acid has to get there = being at least slightly oil soluble. Phosphoric acid in this regard is probably the poorest of all common mineral acids.

- Contains too much water which has to be evaporated at over 200°C prior to use and then it will be super hygroscopic and lead to dehydration reactions if the educts aren’t clean enough (which olive oil will never be).

- May react with the alcohols first forming for example cetyl phosphate or resulting in other weird side products. This would have the advantage that cetyl phosphate is an emulsifier and would serve as phase transfer catalyst but it also means you lose part of the alcohol and part if not all of your catalyst. And the product won’t be the same either or mostly emulsified educt plus some phosphate ester looking like the emulsifier you originally intended to make.

- Even with H3PO4 as catalyst you might have to heat too much and will get unknown side products.

-> Forget citric and phosphoric acid.Maybe you could get sulfamic acid or Amberlist or similar ion exchange resins? Again, get some alkaline catalyst, can’t be that hard.

[Pharma]

NaOH isn’t super great… Every time you use it, you’ll have to make sure it’s really dry or the water in it will always react first. It also creates water by reacting with free fatty acids; it therefore pays off to first neutralise these, dry the oil and then proceed or you’ll end up with twice the amount in free acids after esterification.

For the transesterification, the same rules apply. Methanol is great because it’s volatile and can be removed throughout the process and that drives the synthesis to completion.

Gotta run…

[Pharma]

If you want to perform transesterification, use base catalysis and go the detour via methyl ester .

Acid catalysis works but takes time and/or high temperatures. Also, polyunsaturated fatty acids don’t do well with sulfuric acid (@luiscuevasii it was you who can’t get that anyway, right?). Use p-toluenesulfonic acid if you can get that or simply google some reaction strategies (these days, people use enzymes for esterification and transesterification reactions).

You’ll also have to figure out a way to get glycerol out of the system as it’s more reactive than sorbitol and cetearyl alcohol. Add an excess sorbitol or work under vacuum to evaporate glycerol in case of cetearyl alcohol (that approach won’t work with sorbitol due to their similar boiling points).

[Pharma]

Graillotion said:

…and seeing L-Proline and several natural sources of palmitic acid….and wondering…have I accidently back doored (or been carefully steered) my way into something very similar to pseudo ceramides?…

If you found a back door which nobody noticed until now, you certainly get rich (at least with good marketing skills) and famous (at least amongst chemists) . And no, you haven’t been steered (at least not deliberately).

I just noticed that my vocabulary in this posting isn’t too sophisticated (at least, I’m sorry about that).

However, I told you over and over that you should try ceramides or similar… I’ve even tried to reach your bank clerk to convince her to grant you a second mortgage on your house so you could affort them. However, she doesn’t like you… she said the mailman is only delivering mail and leaves immediately since the day you gave his spouse that pain cream. She’s not happy with your work and won’t support it. LoL!

[Pharma]

As usual, the correct answer is ‘It depends’ .

[Pharma]

@ggpetrov In galenics classes during my pharmacy study 20 years ago, we still had to learn HLB. I never felt comfortable with it and it didn’t make much sense to me (outside the PEG-derivatives), even back then. Also, it usually didn’t work with more complexe formulations. When I found out about the HLD system (the link provided is the best resource you can publicly access and it’s really nicely explained), things started to make sense. You don’t have to understand everything . However, application in cosmetics requires a bit more work because most EACN and Cc values of cosmetic raw materials aren’t available and have a rather pronounced supplier-to-supplier deviation.

The experiments proposed can be done with just a fraction of known values and still guide you towards a better product (good = stable, not necessarily = feeling good).

[Pharma]

@Abdullah It means that the HLB requirement is often just a HLB minimal requirement. Overdoing it will still work (within a certain margin). If the HLB is too low in case of an o/w emulsion it will, obviously, turn into a w/o emulsion if possible (if not possible, the emulsion is usually quite fragile).

[Pharma]

ggpetrov said:

Hello. Lately, I am interested to learn how the HLB system works Don’t. Unless you only work with PEG based emulsifiers. The reason for that is I want to learn how to combine the different emulsifiers, and also how to define the emulsifiers amount more precisely It doesn’t help with the amount. I was reading a lot of information about that, also I have found a calculator in Excel which makes the calculations faster, but I am still confused. Obviously. Everyone in his or her right mind should be confused when applying HLB to real life formulations. It’s only adding up in half of the cases. I never got along with it, too inaccurate in most cases. Okay as a guideline (the HLB values, not the HLB requirement values).

Here is my current lipid phase :

* Cetearyl alcohol - 2.5% Accoring to HLB, this can have a HLB requirement value or an HLB value and be part of the emulsifyer side. According to better systems, fatty alcohols belong to neither.

* Decyl oleate - 3%

* Octyl palmitate - 2%

* Mineral oil - 2% Not a defined molecule, different HLB rey. possible.

* Dimethicone 350 - 2% Not a defined molecule, different HLB rey. possible.

Also, HLB req. depends on the type of emulsion and silicones are not exactly following the traditional route of the HLB system.

The HLB value of this combination is : 11,1

To be honest I am not sure if the all HLB values are correct Good assumption that they’re probably not. For example I have found that the HLB of the Dimethicone can vary in a wide range. But still …

And now the interesting moment. With this lipid phase I am using two emulsifiers :
Glyceryl Stearate SE - 3% SE can mean different types of emulsifiers with different HLB values.
Methyl Glucose Sesquistearate - 1% Not part of the traditional HLB system. HLB value is estimated and usually given as HLB range.
Total HLB - 6 Completely arbitrary number

As I understand the HLB values of the emulsifiers and the oil phase are totaly unmatched So what? If it’s unmatched to one side, it doesn’t mean too much. If it’s unmatched to the other side it only means that maybe/probably the emulsion is inversed or if not, potentially unstable. But, the emulsion is perfectly fine, stable with a great sensorials. The question is why?

The second combination :
Ceteareth - 25 - 0.5% One of the emulsifiers where HLB can be applied IF you stick to very simple systems and by preference micellar emulsions types. GMS plus cetearyl alcohol pull it away from there which explains the no-longer applicability of the HLB system.
GMS - 3%
Total HLB - 5.6 ( This combination is borrowed from the Evonik’s Teginacid’s formulation giude)

Again, stable emulsion and a great sensorial profile -  easy spreading, fast absorbing, no gloss, no stickiness. Again too far from the desired HLB.

The third combination : (according to HLB)

Ceteareth - 25 - 1.4%

GMS - 3%

Total HLB - 11.1

The emulsion offcourse is a bit more liquid because of the redused amount of the GMS.  But the sensorial is totally different. It feels a bit “heavy” than the previous, also it tends to be more sticky and shiny. It also have a fast absorbtion time, but the overal feeling to the skin isn’t the best.

The questions here are two in general :
1. How is it possible to get a stable and fully working emulsions which are totaly out of the HLB system? Because HLB is an obsolete system which only works in a very narrow setting. Other industries do no longer use it… cosmetics, when it comes to that part of the industry, simply has no interest and not enough budget to switch to better systems.
2. Does the sensorial properties related with the HLB of the emulsifier system? High HLB gives heavy and more upleasant sensorial, low HLB more pleasant. Not, no correlation at all. Well, in theory: Low HLB = w/o emulsion = greasy feeling and high HLB = o/w emulsion = lighter/fresher feel. However, you can know as much by looking at the structure of the emulsifier or very roughly estimating the approximate HLB (that’s btw absolutely okay and helpful).

The same situation I got with the Lotionpro 165. Used alone it gives light, but unpleasant emulsions which tend to be sticky and glossy.
To be honest I don’t understand why’s that.

See text in italic.

[Pharma]

That’s like asking: I have that boat, it tends to rock a bit, whatcha recommend?

The answer could be ‘airplane carrier’ or ‘supertanker’ but maybe you would feel more at ease with a catamaran or stick with your current boat but sail on a lake instead of the open ocean.

Alkylpolyglucosides (part of the Montanovs) have a large space where they form liquid crystal structures (aka alpha gels) on the aqueous phase-oil phase-emulsifier triangular landscape called pseudoternary phase diagram. See random example HERE page 8, other landscapes look very different and my not contain all possible phases and mixed-type areas or such of complete emulsion failure.

You can see that even minor changes of either of the three partners or their constituents might push you out of that area, possibly in one where the APGs do what they do second-best: foaming. Understanding emulsion types and your specific emulsion and its parts helps to guide you over that landscape to your target point. How you do that is impossible to predict just by looking at the products composition. However, with some well planned trials you could predict which adjustments are more or less likely to help.

Three strategies I see (on aformentioned page, you’re most likely somewhere on the left side but aim for a lamellar pattern): Use less emulsifier, add low polarity oils at sufficient amounts, and/or add more liquid crystal promoters (by preference of the monoglyceride or sorbitan ester type -> if you’re still in the HLB age = a low HLB co-emulsifier).

[Pharma]

It is, chemically speaking, related to the waxy component in petrolatum . Mix with a liquid hydrocarbon such as isoeicosane and you have fake vaseline, possibly from renewable feedstock.

[Pharma]

LexFeel N200 or N350? I never used these and can’t tell you anything you wouldn’t find online within 10 seconds… However, the silicone alternatives I tried do not considerably help with soaping. This is obvious due to the chemistry of silicones which simply can not be replicated with most non-silicone molecules (some might but they are usually non-cosmetic and fully petroleum base -> the latter doesn’t seem to bother you, the former should). Hence, removing/reducing the ingredient which causes soaping (must be the Montanov) is the easiest option. Simply increasing the oil phase can also help but that comes with possible drawbacks.

[Pharma]

Castor oil can dissolve up to 10% but requires high temperatures and time. Olive oil and other oils can only handle 2-3%. You may add Eutanol G as solubiliser.

Also, polyethylene glycols are remarkably good solvents for salicylic acid.

[Pharma]

If $$ bothers you: Glycerin, propanediol, and/or butylene glycol are your new BFFs.

[Pharma]

1. Formulationg is like European cooking: We already use grams . And I truly believe that a good cook can be a good cosmetic chemist and vice versa.

2. Do some reading on the basics (emulsion principles) before you start anything but anhydrous formulations.