[Pharma]

@PhilGeis Good to know. Maybe it’s because the negative charges don’t really count although it has a very high calculated ‘salt index’. Theory meets practice, in cosmetics that’s every time a surprise!

I still wonder how exactly caprylhydroxamate inhibits microbes and why it targets fungi more than bacteria???

I haven’t thought of pyrithione, a hydroxamate and a thiol in one small cosmetically approved molecule… good one 🙂 !

[Pharma]

People get allergies from everything, more so from plants than synthetics… I don’t think that lecithin could help prevent an allergy. However, aescin formulated with bad mojo might cause irritations. Aescin is a saponin, a ‘herbal soap’, and detergents, as you know, can be harsh or mild depending on how they are blended. Saponins are usually regarded as mild surfactants but sometimes that’s already too harsh for some people.

[Pharma]

@PhilGeis Isn’t phytic acid the worst of them all? No other chelate can have that many negative charges…

As an educated guess, caprylhydroxamic acid would be better suited because it does form fairly stable complexes with metals but isn’t deprotonated to any significant level at a pH usually used in cosmetics (except soap). Personally, I wouldn’t bet on that compound. Kojic acid goes in the same direction…

Another more potent hydroxamate, though with one positive charge, would be deferoxamin LoL. Joke aside, some polyphenols complex/chelate metals, though mostly trivalent ones (Al3+ is of no concern and Fe3+ does not exist in a cosmetic which contains antioxidants) and/or in alkaline conditions. Copper could be complexed with thiol ligands but common ones such as penicillamine are also electrolytes. On the fancy side of things, Salen ligands and similar would be very good non-electrolyte chealtes… though they are not approved for cosmetic use.

[Pharma]

@”Dr Catherine Pratt” Here around, hobby beekeepers and small scale private honey producers are booming and well organised for example under THIS label. Beeswax isn’t what keeps them going, it’s honey and fun .

I just wish more would cultivate the native European dark bee instead of Carnica, Ligustica or Buckfast and other hybrids…

@emma1985 I like olive wax, has a nice feel. However, it’s not a wax but a blend of straight chain hydrocarbons, squalane and other unsaponifiables. I haven’t tried to use it as oil gellant because I assume it wouldn’t work anyway.

[Pharma]

Electrochemistry says no.

[Pharma]

Yes, there are; such which disrupt and such which stabilise. Depends on the whole blend (really, the WHOLE cocktail, not just an EO meeting an emulsifier) and this is, by common means, totally impossible to predict ;( .

There are several mechanisms in play, some are somewhat understood, others are educated guesses and extrapolations, and the rest is speculations & hypotheses.

As a general rule of tumbs, I would say (and this is pure assumption) that the chances that an EO destabilises a lamellar structure is more likely than the opposite. Unsaturated, branched, or cyclic hydrocarbon EO constituents are more likely to have a negative than a positive impact on liquid crystal structures but are tendentially the ones with the lowes chance to actually interfere with the emulsifier layer. Ketone and aldehyde EO constituents… dunno… probalby close to the aforementioned ones. Phenolic EO constituents have a high chance to actually do something with an emulsion but the effect may be either way (depending on everything) with maybe, just maybe, a higher chance for a positive outcome due to them interacting more likely with the interface than the oil phase. Alcohol groupe containing EO constituents are probably the ones which have the highest possibility of negatively interfereng with liquid crystal structures due to them intercalating with the emulsifier/co-emulsifier tails. Functionalised monoterpenes are also more likely to interact with emulsifier layers than the more lipophilic diterpene counterparts whilst corresponding sesquiterpenes are likely the ones which most readily interlocate with the crystalline part of the interface.

Generally, unsaturation, branching, and cyclic structures are more likely to reduce rigidity of lamellae and introduce defects into crystal structures, no matter whether they are part of the emulsifier, the oil phase, or some added actives or essential oil. Except some phenolics, most EO constituents have one or several of these structural elements, that’s the reason why most are low viscosity liquids and likely also why people more often complain about EOs killing their emulsions than raving about their benefits for stability.

Again, this is speculation and a not very helpful one at that either. This is because essential oils are usually blends of dozens to hundreds constituents very often comprising most of the abovementioned chemical families with highly fluctuating composition between batches…

Bottom line is: Best add EOs only after lamellar structures have been formed, dont add too much EOs, and add them together with a solubiliser. Alternatively, include them into an oil phase and add lamellar structure builders as separate phase. Both strategies would reduce the chances that EO constituents meet crystalline structures.

[Pharma]

DeepTitan said:

Hi, I don’t understand concepts well enough (obviously… no offense!), so appreciate if you can correct my understandings below, appreciate it.

a) I read somewhere that you use for transdermal drug delivery, cationic polymers (i.e. positive charge polymers) as skin and hair are negatively charged, so these polymers bind to the skin, and in that process, the product gets a chance to permeate through the skin barrier. Are you sure you don’t confuse it with transfection? Polymers on dead matter usually don’t work (with some exceptions but applications therewith are highly limited).

b) so while the above is merely one component (i.e. binding to skin Precisely, it binds to skin and then sticks there) of topical delivery science, another would be to force the product to actually enter the skin (that’s one of the standard ways to do it, it’s called occlusion and works by the principle of solubility/insolubility).  I can see 2 methods: 1. diffusion (that would be the another standard which it the one probably most often referred to in cosmetics when talking about penetration enhancers), 2. transport (in cosmetics, one can rarely use a transport system for an active ingredient mostly because it involves covalent binding and living cells which are only reached after the hard part has been achieved i.e. penetration through epidermis).  What factors help diffusion and transport? Laws of physics and principles of biology

c) Diffusion: I can think of pH of product solution as helping with diffusion? Anything which creates a gradient such as pH may be used for some things under certain circumstances. However, pH is mostly used to tune lipophilicity/hydrophilicity of acidic and alkaline actives.  Transport:  As for transport, maybe mixing an ingredient that has a skin transporter present? (??? You mean like gene technology?)  What would be transporter ingredient? Again, ???

d) so what happens if you combine cationic polymers (such as chitosan, guar gum) with anionic (such as xanthan gum).  You end up with a Polyelectrolyte Complex.  1. Would that be not suitable for Transdermal use? Likely not. What’s the point of that most likely precipitated blend anyway? 2. Would the application be for oral delivery instead? Why?

e) Can you comment on this topical formulation with least ingredients but still sufficient to penetrate at least in epidermal, but preferably in dermis as well: 

Active ingredients (safe even if goes into systemic circulation): x (hard to dissolve, lipophilic product), y (hydrophilic product) If you use both, the vehicles for the two will have to be different, unless you use some injection device such as CLICK.

Solvents: 1. try to dissolve in healthiest oils first (Define healthy. Why an oil?).  2 If fail, Glycerin, 3. If fail Propylene glycol If it fails with glycerin, why should it work with propylene glycol?

Polymers: For max skin absorption: what do you think about: Gum arabic (it’s used for oral drug delivery of lipophilic actives) vs Guar gum vs Chitosan vs Xanthan gum vs Sodium Hyaluronate.   How would each fare for dermal vs epidermal absorption? Absorption of what? An active or the polymer itself? Low molecular weight hyaluronic acid does penetrate to a degree, against all predictions and principles of skin penetration, though I’m not aware that this would help penetration of other ingredients in any regard. Same goes for a very few other polymers such as heparan. Chitisan, if properly formulated, may work, the others are just polymeric thickeners and gel builders.

Short-term stability/preservation: citric acid, edta That’s not preservation, that’s chelation. Also, they are partially incompatible with chitosan and do not really contribute to physical stability.

f) Is there something lacking in above. Yes, there is: some books on your shelf and a sound basic knowledge. Again, no offense.  How do you think about adding sunflower lecithin to the above? I think that reading those books first… or maybe just buy active ingredients encapsulated in lecithin based liposomes or the like might be easier.

Thanks a lot, sorry for this being long.

See comments in italic.

[Pharma]

Did you try to make/use it?

There’s a good discussion about said topic here somewhere. Keep in mind that you can’t dissolve 15% azelaic acid without turning it into an effectless salt.

[Pharma]

@PhilGeis Would you rather buy a 30% industrially mined and highly refined magnesium chloride lake or Magic Magnesium Oil? One of the first, if not the first to start the hype, was called Zechstein Magnesiumöl (can’t find it anymore, thousands of copy-cats around) depicting an idyllic village in the Netherlands… Consumers think that said village is Zechstein and don’t realise that Zechstein is a sediment layer spanning over big parts of northern/middle Europe from which not just MgCl2 but also rock salt is mined and which shows as the magnificent white cliffs in England. Good marketing, that’s what it is.

[Pharma]

Depends on how much magnesium chloride you use . ‘Traditional’ magnesium oil is 30% salt; no need to add antyhing else to that, it’s self-preservating.

[Pharma]

Check out the other thread . The colour of hibiscus changes with pH, under others green. You can’t do anything about that, no matter which alkaline substance you use to increas pH.

Graininess is another thing, though…

[Pharma]

It’s a PDF download.

I can’t find it in another form (the one I found on Akema’s HP isn’t quite the same and lacks the important information).

[Pharma]

Just bear in mind that the colour of hibiscus (anthocyanidins) depends on pH. At a pH closer to neutral it may shift through pink, purple, and sometimes also colourless; in the more alkaline range, it’ll be blue, green, yellow…

The colour is most stable at an acidic pH in the range you currently have. The more alkaline, the faster the colour will dissipate.

If a strong colour is important, you may add certain metal salts (however, not just the intensity but also the shade of the colour will change).

[Pharma]

Does THIS work?

[Pharma]

Graillotion said:

…Maybe @Pharma will chime back in…

For a bottle of good wine, I might

[Pharma]

Fatty alcohols aren’t electrolytes and fatty acids only after neutralisation (i.e. soap). The ‘saltiness’ of a molecule depends on its charges (anion and cation) and its molecular weight. Amphiphilic molecules such as emulsifiers have a ‘saltiness’ of roughly 1/3 of what you would calculate based on that; 1 part sodium stearate corresponds to ~15 parts table salt = its salt effect and carbomer interaction are minor.

[Pharma]

Regarding solubility etc. HERE‘s some nice reading.

[Pharma]

Why do you need the alcohol gone?

[Pharma]

Squinny said:

…

Cyclopentasiloxane: Main ingredient, it’s volatile. The more you take,

the less greasy the product will be after ‘drying’ (10-20 min?)

Dimethicone: To add occlusion, cushioning, it’s the main ingredient

you’re going to feel after ‘drying’

Dimethicone/Vinyl Dimethicone Crosspolymer: Film former & viscosity

modifier, often comes as blend. Use this or similar at an amount which suits your needs. Go with manufacturers recommendation as a start.

Hydrogenated Vegetable Oil: Oil thickening ingredient. Low %, may be left out or replaced with other ingredients.

Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer: See the other crosspoylmer.

Silica: Texturising ingredient, reduces oiliness, gives powdery feeling & might increase viscosity. Usually used in the low % range. For trial and error runs: just add different amounts to the final product, homogenise, and see if you like the texture (not super accurate this way but a good & fast estimate).

Disteardimonium Hectorite: Maybe the main oil thickening ingredient. Often comes as blend with the next three ingredients and cyclopentasiloxane. I’d rather use this than hydrogenated oils; usage rate is probably in the range of +/- 5% (of a blend!).

Pentaerythrityl Tetraisostearate: Cushioning emollient & film former which imparts some degree of gloss but may likely be omitted

Alcohol. Likely part of the hectorite or other blend. Omit if you want to

Tocopheryl Acetate: Not required, likely part of a blend

Butylene Glycol: Likely not required cause likely not enough for hydration. However, the glycol phase is likely to hydrate/swell with sweat and air humidity… not sure if the effect is actually noticeable

Silica Dimethyl Silylate: Thickening agent for the glycol phase, maybe also part of a blend, omit if no glycols etc. are used

Acacia Senegal Gum: Likely the emulsifier for the glycole phase, omit if no glycols etc. are used

Phenoxyethanol: Preservative, not using it may be okay if only silicones & no glycols are used

Caprylyl Glycol: Preservative, not using it may be okay if only silicones & no glycols are used

Hexylene Glycol: Preservative, not using it may be okay if only silicones & no glycols are used

@Squinny See comments in quote. As a starting point, just mix the first two ingredients at different proportions (more cyclo than dimeth) and try them out, mostly regarding oiliness and residue on skin. Then add a silicone polymer and/or disteardimonium hectorite to adjust viscosity. Use silica to fine tune (if dimethicone feels too greasy). That should give you a fair dupe or at least a good basis with which you can play and add some % of your own favourite (oil/silicone soluble) ingredients. Water/alcohol/glycol soluble ones may be dissolved in alcohol/glycols and adsorbed to silica prior to its addition .

@Abdullah It’s an anhydrous formulation with a volatile silicone oil as main ingredient; heat drying doesn’t help here.

[Pharma]

If you were to use a lever (and applied some basic physics laws), then you could also claim ‘hand pressed’ .

Get that thing out of the box! Imagine you manage to make a hand pressable formula and then use the press and it won’t work any longer… would be a shame, wouldn’t it?

[Pharma]

With a standard vesicle, you’d be right. A multilamellar one is composed of several concentric ‘cell membrane like’ structures, like an onion.

However, the similarity ends there and is heavily exploited by cosmetic marketing. Only because the arrangement and (sub-)microscopic features look similar doesn’t mean they are. Hair conditioner and traditional soap also form lamellar structures (in this case, they look more like puff paste or, in marketing terms, similar to stratum corneum lipids LoL)…

[Pharma]

It’s a term invented and patented by Neopharm (CLICK). The science behind it isn’t new; it’s actually as old as emulsions, we just weren’t aware of the particular strucute and thought of emulsions as droplets floating in a continuous phase. Lamellar this and that is just very hyped at the moment but such structures were already present in cosmetics sold a hundred years ago, even mayonnaise contains them. The invention refers to multilamellar vesicles (a type of liposome). However, without freeze-fracture TEM they can’t really know wether or not they have what they claim. The composition of the lamellar structure is only ‘new’ due to a pseudo-ceramide they use instead of, say, traditional lecithin. Lamellar gel networks are non-specified lamellar structures which may or may not form single or multilamellar vesicles and even sheets around emulsified oil droplets or just ‘float throughout the water phase’.

By reading a LOI you can actually guess with high accuracy (one only knows with a polarised light microscope and/or freeze-fracture TEM) if a product contains lamellar structures and which typ of it. Some ingredients, depending on manufacturing process, may fairly easily form multilamellar structures (such as lecithin). Again depending on the manufacturing process, such multilamellar structures may be a type of vesicle… this however isn’t visible in the LOI, you could just guess that a product which contains certain ingredients (lecithin or the alike, sterols, and fatty acids or similar -> note the AND) could, if properly formulated, contain multilamellar vesicles. Production of these is not very production friendly due to high costs and labour and it might be easier for a company to buy a multilamellar pre-mix and add that to their product so their marketing department can exploit the hype.

[Pharma]

Maybe have a look at some sample formulations, for example by Kobo.

The main difference to you is production methods: they micronise/homogenise (that’s something you can’t do with a coffee grinder) and they press real hard (you’re pressing with probably 2 bar, a bit more if you’re a bodybuilder… they propose about 30 to 60 bar) .

60 bar is when you use your whole body weight to press down 1 square centimetre of powder or you and 8 friends sitting on a 3×3 cm square.

[Pharma]

@Fekher I only know that they get aggressive here around and during the warmer seasons, especially when it’s dry and hot like this year and they are very much attracted by sweets and sting unprovoked when they’re hungry. Wasps are likely not that much nicer in other parts of the world… I simply lack personal experience on other continents, that’s all .

[Pharma]

How do you process your ingredients and how exactly do you make your pressed products?