[Pharma]

@thejoggler Nice update! However: How do I cite a post? And, BTW, I think I’m typing too fast, it’s often lagging and the cursor disappears for a second or two… didn’t happen before.

@fotis83

What’s active:

A) Menthol (3.7%) Gives a cooling sensation, Arnica Montana Flower Extract Might (depends on quality and quantity) be anti-inflammatory and is commonly used for bruises and injuries, Dimethyl Sulfone (MSM) Allegedly active on skin though likely just a claim… better eat it if you have a chronic inflammation, Melaleuca Alternifolia (Tea Tree) Oil Extract Can give a perceived effect, doesn’t do much for muscles

B) METHYL SALICYLATE anti-inflammatory, penetrates skin well, most often used ingredient in creams and gels for your indication, EUCALYPTUS GLOBULUS (EUCALYPTUS) LEAF OIL Can give a perceived effect, doesn’t do much for muscles, MENTHOL Gives a cooling sensation which is comforting but doesn’t do anything beside feeling cool on the skin, CAPSICUM FRUTESCENS RESIN Heating effect (exactly the opposite of menthol), can have an analgesic effect in sufficient quantity (with regard to capsaicin) which is better used against nerve pain, not sore mucles

That’s about all… Personally, I wouldn’t buy either of the two but if these were the only two products on the plante… maybe version B? But that depends on the amount of added ‘actives’.

[Pharma]

The theoretically correct answer would be: Instability or incompatibility causes this 😉 .
As mentioned before, without a detailed composition, it’s impossible to guess what’s happening in your case.

[Pharma]

This is not a chemistry corner but a cosmetic chemistry corner… meaning, it has usually nothing to do with chemistry but only with mixing cosmetic ingredients (hoping that they don’t undergo any chemical reactions).
Synthesising H2O2 is fairly simple and there’s just one approach being used by nearly all manufactures. This strategy is scaleable and not too difficult to perform (for a real chemist, not a cosmetic ‘chemist’).
However, given that you plan a pilot plant imlies that you’re running a different chemical route… which means, only you can answer the question.
Besides all that, with the scant informations you share, it’s impossible to give you an answer. For all we know, you might be better off buying concentrated peroxide and dilute it down to your 6% 😉 .

[Pharma]

Gordof said:

…
For a visual effects, I don’t have an idea for that right away.

Wouldn’t that be those ingredients having a ‘soft focus’ or ‘matte’ effect? Certain silicones and modified starches and the like would, again, fit that bill.

[Pharma]

Aliacura*, Manske-Shop*, Skinchakra - Germany

Farmaciavernile* - Italy

Kosmetikmacherei - Austria

*I did order there before (also at Alexmo) and can recommend these shops

Glamourcosmetics has quite a nice assortment of (let’s call it) less natural ingredients which the other shops don’t offer… sad enough, they don’t deliver to my country.

[Pharma]

@Paprik True, gelling the outer phase is way more important but 5% wax takes care of that easily .

Assuming it’s not a traditional w/o emulsion (water droplets in a continuous oil phase), gelling the water phase to some degree certainly isn’t a bad thing to do.

[Pharma]

OliviaLeigh said:

… why would the cetearyl alcohol possibly change it to an O/W, if that’s what you mean …

I’ll try and lower the candelilla wax too, and gel more water with more HA powder, CW does have a high absorption rate so not too heavy, sticky or waxy, but could go down …

No, not into a classical o/w either . There’s a few more emulsion types possible, one looks like lasagne, hard to tell what’s the inner or the outer phase, the pasta sheets or the sauce layers.

I’m not saying you should, let alone have to, reduce or increase anything, if you like the haptics, then that’s abosolutely fine. Two months shelf life for a DIY project for personal use, that’s also okay I think. BTW gelling the water phase with HA is expensive…

[Pharma]

I would guess that the thing which keeps your emulsion stable are the 5% candelilla wax . It’s actually a lot but if you like the feel, there’s nothing wrong in using that much.

Gelling the water phase for example with HA or xanthan also helps (even more in o/w emulsions).

Magnesium sulfate and other salts can, but don’t have to, stabilise w/o emulsions. If its stable without, the better. You could add sodium lactate and/or sodium PCA; both serve as salt (not as potent as Epsom salt) and humectant.

Oh, and with 5% cetearyl alcohol I would guess that chances are there that you don’t have a traditional w/o emulsion.

[Pharma]

Small water soluble ingredients may even penetrate better with a w/o emulsion due to occlusion and ‘anti-solvent’ effects (better soluble in skin than in product after water evaporated). I don’t know how well HA and other polymeric humectants would perform…

Apart from that, I doubt that your emulsions are going to be stable if you only use polyglyceryl-4 oleate. Also, should you add enough fatty alcohols and/or glyceryl monoesters, this ingredient is more likely to form lamellar structures than a w/o emulsion . This would result, IMHO, in more flexibility and a higher chance for stability. Such lamellar structures are also good in reducing TEWL.

[Pharma]

Unless it dissolves spontaneously, yes.

[Pharma]

Your question isn’t just about two nearly identical and fully
biodegradable ingredients, it’s about most cosmetic ingredients with
that property, it’s about petroleum vs. renewable feedstock. I did the
maths ‘over the thumb’ in another thread: if 1 barrel of crude oil could
replace one barrel of canola or hemp oil, we wouldn’t have enough space
(not just agricultural but simply ‘land’ in the broadest sense) on our
planet to grow enough plants to replace all the oil we drill.

Solution 1: Use less

Solution 2: Reuse (not the best idea with cosmetics)

Solution 3: Realise that recycling doesn’t work and go with 1 and 2

Solution 4: Create/synthesise/assemble stuff which can be recycled/upcycled

Solution 5: Don’t use stuff which isn’t necessary, such as most cosmetics

Solution
6: Use the traditional approach = let the next generation worry about
it… Besides, what’s 1 person (usually me, not the other one) amongst 8
billions? So, don’t you worry, someone else will find a solution with
technology which hasn’t been invented yet. It always worked (for humans,
not nature)…

[Pharma]

Just for the fun of it: the 11 -OH (9 in brackets and the two on the right side of it) each count 1.9 according to the method by Davies.The ester (left of the brackets) counts 2.4, the nine ethers (the -O- on the right side within the brackets) count 1.3 and the 42 carbons each -0.475.

Add this up and add 7 = HLB = 22.05. As you can see, a totally arbitrary and obviously wrong number .

As @ketchito said: HLB was made for PEGylated fatty acids and alcohols and sorbitan fatty esters and PEG derivatives thereof (e.g. Tween, Span, Myrj, Brij, and older Arlacel, Atlas, and Atlox series, to mention just a few). The system isn’t even working well with Tritons, Pluronics, branched or polyblock polymers, and extended surfactants, let alone valid for glucosides, polyglycerols, ‘biosurfactants’, lamellar gel network promoters, and all the other newer types.

[Pharma]

The Thai place has it, along with PG-10 isostearate and oleate if you want a liquid version and a bunch of other PG-10 esters too.

Can’t remember having them seen there last time I placed an order…

I suppose, of all the polyglyceryl esters, the 10 comes closest to 165?

[Pharma]

Wikipedia gives you two different methods for calculating HLB values of unknown/new compounds.

Are the results accurate? I don’t know… what I know it that several polyglyceryl esters can form lamellar structures and then do not comply with the HLB system. Also, most manufacturers give HLB values for their emulsifiers… not because these values are any good other than telling you if the emulsifier has a certain preference towards one or the other emulsion type (o/w vs. w/o) but because of tradition. The HLB system is a very persistant relic in most applications but sad enough, it’s the only one most cosmetic chemists care about (the smarter ones go by experience, gut feel, common sense, and trial and error).

Estimating from related emulsifiers, PG-4 laurate should be in the range of HLB 13-14.

[Pharma]

350 cSt dimethicone has a molecular weight in the range of 13’000-15’000 g/mol depending on the manufacturer (some sources say half that number). What I found is, that 27 kDa corresponds to 1000 cSt dimethicone… it’s a mess…

300 g/mol is slightly above the molecular weight of the tetramer which has a viscosity of ~1.5 cSt.

Viscosity of polymers usually varies greatyl because they aren’t pure but blends of different chain lengths. Dimeticones are sometimes also branched and not exclusively linear, contain additional siloxane moieties, or may be endcapped etc. which all affects viscosity.

Bottom line is, dimethicone 350 contains approximately 200 monomers and dimethicone chain length doesn’t have a linear correlation with viscosity. If memory serves me right, dimeticones above ~6 cSt aren’t volatile and can be added to the hot phase without any losses.

[Pharma]

chemicalmatt said:

…I know this annoys one of our esteemed colleagues here, who has been adamant about dissing the HLB system all along (and you know who you are.)…

Not in all cases but most. It can work in simple systems… this one does look simple. However, it’s actually not even a classical HLB emulsion but a lamellar structured emulsion (10% fatty alcohols) and hence, the original HLB system doesn’t apply (not saying it can’t be stable, I’m saying that HLB math doesn’t matter). Sorbitan esters also form lamellar structures and the roughly 12% ‘high HLB’ emulsifiers are in the recommended range for proper hydration of the ‘low HLB’ emulsifiers (Span plus fatty alcohols). As a result, the proportion Tween to Span might have been copied from Griffin (with an -N, not a -TH 😉 ), might be LGN formulation, or just a coincidence or found by trial and error.

In addition to that, the 20% PG result in a higher apparent HLB as would be found using standard HLB calculations.

And that’s one example more in my collection of ‘Why not to use HLB calculations in cosmetics’.

Sorry @chemicalmatt, I simply couldn’t help it :blush: .

[Pharma]

So it is in mine. Good for you though, it was only one out of three.

[Pharma]

The two aren’t the primary surfactants, they’re just first on the LOI . The surfactants are the four subsequent ingredients.

[Pharma]

@RocketDog Appology accepted and no hard feelings.

I admit, I was quite pissed this morning… reading something like that (the way I understood) isn’t exactly the way you want to sip your wake-up coffee, right?

I know that English is only my third language and that chances are there, that I might not get everything in a text (e.g. the parts, which aren’t written in words). So, obviously, I’m reading your reply and I’m glad I misunderstood and also that I didn’t write what I felt like calling you this morning. :smiley:

[Pharma]

RocketDog said:

Pharma said:

Why on earth do people touch and even mix chemicals without some basic knowledge of chemistry and the stuff they’re handling? 

Oh, oh! I know this one (wildly waving arm)! It’s the Dunning-Kruger effect, right? Or as we used to say in graduate school, “it’s takes some bit of competence to recognize your own incompetence.” 

(And that’s what you all get for letting a psychologist in here.) 

-Rocky

@Rocky Looks like you got the wrong forum for a pissing contest. Go elsewhere because:

- People like me and a handful of others share their knowledge and time worth thousands of $$ for free. Respect them and be grateful, don’t insult them.

- I’m a PhD pharmacist with a solid background in chemistry and I did instruct students in the chem lab. I know how much knowledge and intelligence it requires and what can happen even then. It’s not waving arms for nothing.

- I do not succomb to the Dunning-Kruger effect (or, if all humans do, I’m on the weaker affected side). I really have an IQ of around 130 and I do know the limits of my competences.

-> If you really are a psychologist, you should know that this here it the point where you should just shut up and walk away.

[Pharma]

For me, it’s mostly about fun, getting to know what the single ingredients do, and knowing what’s inside and how much is inside. Also, I like those theoretically/sientifically cool/nerdy formulations with aren’t commercially available (which they aren’t for more than one good reason LoL).

The common hygiene stuff, shampoo and cheap body lotion, I buy. DIY is usually more expensive than that. Facturing in all the stuff on my shelves which I might use just once out of curiosity, I’m certainly not safing any money by making my own products even if a product itself might be less expensive than a comparative store bought one.

[Pharma]

Abdullah said:

What factors has influence on micelles size and makes them smaller in an emulsion? 

Which factors? Basically everything you add to an emulsion, how/when you add them, and how you process it.

What makes them smaller? Besides everything (which can also make them bigger or longer and any whatever form), the main factor which makes them small is energy. This may come from high sheer or pressure, ultrasound… Lower energy strategies involve PIT and PIC emulsification.

Where to start? Stevenabbott.co.uk is nice and free lecture with tons of useful information (if you’re willing to go into detail and sciency stuff). It’s not a guide on ingredients and doesn’t give you formulations, but tools .

[Pharma]

MarkBroussard said:

…the chemical structure of D-Panthenol …resembles a sodium hyaluronate monomer in terms of functional moities.  I would presume that D-Panthenol is able to form hydrogen bonds with sodium hyaluronate and displaces the hydrogen bonds between individual hyaluronic acid chains that accounts for its viscosity.  

@MarkBroussard Not really… True, some interactions aren’t obvious or predictable just by looking at structures. If it were the simple interaction you describe, then pentylene glycol, lactic acid and many, many more ingredients would be as likely to interfere with HA (and panthenol with all kinds of anionic polymers, respectively). Viscosity in case of hyaluronate heavily depends on the carboxylic acid moieties (or rather the sodium salt thereof). Interference would have to involve an acidic proton (not necessarily an acid = low pH but something more acidic than an alcohol) or a ‘salt overload’. Panthenol can’t do either.
I’m not aware of any incompatibility between the two and can’t see how this could happen but that doesn’t mean anything. As said, some molecules do like each other more than what meets the eye but I would assume that an interaction between two very common ingredients should be known. Maybe search on PubMed, ScienceDirect, or ResearchGate (@LeoCosm).

[Pharma]

You could as well use potassium hydroxide or arginine base if these were easier to source in small quantities where you live.

With NaOH and the two abovementioned bases (and ammonia, which I advise against…), you can pretty much obtain any high pH you want to, with bicarbonates you’re limited somewhat. It’s a very poor base and it’s neutralising property relies mostly on the formation of carbon dioxide. Evaporation thereof results in a loss of acid and hence the pH increases.

Sodium carbonate aka washing soda would be more efficient than sodium bicarbonate. It’s a stronger base and therefore neutralises also because of its high pH and not just CO2 formation (it also results in CO2 if there’s enough acid present and/or if added slowly enough) but it may not be available as cosmetic, food, or pharma grade.

Sodium carbonate aka washing soda would be more efficient than
sodium bicarbonate. It’s a stronger base and therefore neutralises also
because of its high pH and not just CO2 formation (it also results in
CO2 if there’s enough acid present and/or if added slowly enough) but it
may not be available as cosmetic, food, or pharma grade.

Using bicarbonate is safe but it has the dendency to mess with our product in different ways (under others: slow CO2 evolution happening after you closed the lid tight… happy cleaning when it goes *PLOPP*). If you find an alternative, better use the alternative.

[Pharma]

Edit: @thejoggler Trial didn’t work and I can only copy the URL to the whole discussion ;(

Re-Edit: But I can reply to just you or the whole thread 🙂