[Pharma]

ORAC is just on of many antioxidant tests done. Each has advantages and peculiarities and may be extrapolated to some conditions but not to others.

There is not THE strongest antioxidants, there’s just some which are under certain conditions better than others or such which are no, poor, mediocre, or good antioxidants. The good ones may be piss poor in test A but excellent in test B.

The best you can do is to combine the right ones to cover the full spectrum. Regarding rancidity, adding a chelate and avoiding any addition of iron containing ingredients (e.g. clay and many colour pigments) greatly boosts any antioxidants effect!

Commonly, a vitamin C derivative plus a phenolic antioxidant are employed.

[Pharma]

@”Dr Catherine Pratt”? Guess I miss something here (lost in translation or overworked?), sorry ;( .

Petroleum jelly is safe. Legend has it that the guy who “invented” Vaseline (IIRC he, I unfortunately forgot his name/company, didn’t but was owner of a large petroleum company and actually died not that long ago) eat a spoonful petroleum jelly every day till his last breath. Said it helped his digestion (paraffin oil which is chemically very similar is used for that purpose) and maybe, just maybe, was the source of his health and long life (the petroleum or his good digestion remains elusive 🙂 ). Since petroleum is derived from crude oil, early and less pure fractions/distillates were/are certainly unhealthy or worse (think diesel fuel or oil spill, respectively). Modern, purified aliphatic hydrocarbons are safe as can be. Like Catherine said, there were a lot of ‘actives’ in cosmetics in days past which contained heavy metals, poisonous plant extracts, or *gosh* were even radioactive!

This brings me to @Cst4Ms4Tmps4 Nice link! Thanks for sharing! Can’t vouch for everything (because it’s not in my expertise) but there’s a fair deal of truth in it.

[Pharma]

Best is to ask your client for a list of preservatives they define as ‘natural’. Some of the ‘bad chemicals’ also exist in nature whereas ‘natural’ ones don’t exist in nature. Also, several of both classes are produced in a similar fashion just that one is based on ‘chemicals’ (often petroleum derived, but not necessarily) and the other on renewable resources.

Furthermore, ‘natural’ or better call them alternative preservatives are even more dependent on what you want to preserve than ‘chemical’ or better call them traditional ones.

Cosphatec as an example has a nice list of different preservatives.

[Pharma]

Cst4Ms4Tmps4 said:

… I have been wondering how come Glycerin is seemingly the only thing that gets absorbed that efficiently, it is not even cationic…

…Can Sorbitol penetrate aquaporin and be resorbed like Glycerol?
Sorbitol is twice the size of Glycerol. Does molecular weight matter in this instance?…

Is that aquaporin very important?…

Cationic only gives compounds a ‘gluey’ characteristic, being without charge makes them more fat-soluble and hence better for assimilation/penetration.

Yes, it can. And yes, size matters. There are many types of aquaporins. I don’t know the molecular cut-off of these but since they are there to transport much more than just water between/into/out of cells, such as sugars, urea and even mineral ions, it’s highly likely that sorbitol will be transported as well. Sure, there is an aquaporin family extra for glycerol and hence, glycerol might be favoured over sorbitol which has to use ‘sugar’ aquaporins (glycerol can use these too).

I don’t know how important they are in cosmetics… they’re hyped, that much I can say !

THAT might help.

[Pharma]

That’s what I’ve learned too. Silicones ‘breath’, so to say.

What’s your difference between mineral oil and petrolatum?

[Pharma]

Zabi said:

Yes mercury is banned but tell me the process of using.

You won’t get a recommendation because mercury is banned in most countries for most uses. There are exceptions but you’re not part of those or you wouldn’t ask said question.

Also, betamethasone and other cortisones have nothing to do in cosmetics, they are pharmaceutical drugs and in many countries are even prescription drugs.

Maybe ask your government for advice?

[Pharma]

Hirondelle21 said:

…zap in the microwave for 30s…great for travel. ‘merica, where people have a built-in microwave in their car! :smiley:

…100% natural is a tall order and also that natural is a pretty loose term… A good part of the ingredients may be from renewable resources; if that qualifies as 100% natural… marked these with a *

Ethylcellulose 1.5 * Oil gelling agent, may be switched with other stuff

Diisopropyl Adipate (this has got me
head-scratching) 13.5 * As (un-)natural as above product; the isopropyl-moiety is often through petrochemistry but may also be sustainable. Light polar “solvent” for ethylcellulose, might probably work with isoamyl laurate? But that one is also not 100% natural, just 100% from natural resources.

PHASE B

Octyldodecanol (and) Pogostemon Cablin
Leaf Extract 0.67 * Octyldodecanol may be derived from petroleum or plants… usually not regarded as natural.

Oxidized Corn Oil 6.03

Cocos Nucifera (Coconut) Oil (and)
Hydrogenated Soy Polyglycerides 15 * Hydrogenated polyglycerides are of natural origin but synthetically modified. May probably be replaced with other butters?

Myristyl Myristate (and) Myristyl
Laurate 5.6 * As synthetic/natural as isoamyl laurate or any other of the “modern good guys”.

Bis-Stearoxydimethylsilane (and)
Stearyl Alcohol (and) Dimethicone

(Cetyl Palmitate?) 10 Finding a silicone replacement might prove difficult. BTW stearyl alcohol is synthetically modified stearic acid. Cetyl palmitate might be of petrochemical and/or natural origin (and it’s palm oil derived like many of the ingredients in here).

Glyceryl Stearate (and) Behenyl
Alcohol (and) Palmitic Acid (and) Stearic Acid (and) Lecithin (and)
Lauryl Alcohol (and) Myristyl Alcohol (and) Cetyl Alcohol 28 * Again those fatty alcohols…

Synthetic Wax (Rice Bran Wax) 3

Cera Alba  (carnauba wax) 6.5 Or a mixture of carnauba with candelilla wax since carnauba is harder…

PHASE C

Guar Hydroxypropyltrimonium
Chloride 1.2 Depending on synthetic route, partially synthetic to very synthetic (only the guar is natural). No 100% natural alternative available, only semi-synthetic non-polymeric cations with a higher % of “natural”

Sodium Polyacrylate (polyglutamic
acid?) 8 Synthetic polymer which may be replaced with a bunch of other natural polymers, polyglutamic acid might be too “slimy”.

…

See comments within your quote.

[Pharma]

IPA dries faster and comes, at an affordable price, water-free whilst ethanol is usually no more than 96% or, if anhydrous, is fairly expensive.

Solubility properties aren’t better or worse, they are simply different. Higher hydrophilicity and polarity plus contaminating water and slower evaporation renders ethanol less suitable for airbrushing (higher elution power) unless you like a more ‘diffuse’ colour. Droplets are also tending to dry into coloured circles instead of coloured dots.

[Pharma]

Could also be Cosmospheres (i.e. microcrystalline cellulose plus lactose or mannitol) .

[Pharma]

raiyana said:

… “are you pregnant? are you breastfeeding?”….

Unfortunately, that’s about common practice ;( . I think that at least in Europe and USA, two negative pregnancy tests before the first prescription and double-contraception (or no sex but what are the chances that a 15 year single today might not be single in 1 year) plus only treatments for 30 days (for women) with a pregnancy test every subsequent month/package are mandatory. But real life out there tells a completely different story.

Weird enough, I can’t find that warning we’ve got nor can I find that alleged retrospect study… I’m currently on a few days vacation so I’ll have to check next week at the pharmacy if I can find either the mail or the letter somewhere there. Really bugs me cause it WAS there (am I hallucinating or what?)!

[Pharma]

pccochran said:

…Why would taurine have that kind of preservative effect? … 

It is likely the coincidental result of ionic strength, ion type, buffer capacity, and probably pH which has an impact on Debye length, Zeta potential, and electrical double layer which in turn affect emulsion stability.

Taurine being a zwitterionic aka inner salt makes it likely (but not obligatory) that it’s addition can reduce adverse effects of other salts on emulsion stability.

Given the high electrolyte concentration, I’m not sure how well predictions are possible and how far it’s just a lucky find.

[Pharma]

Fortunately, skin penetration is piss poor for tretinoids! But they all rely on living cells because their effect is mediated via gene expression. Faster shedding is due to faster cell differentiation/maturation = (hypothetically) faster cell life = earlier death (cell cultures ‘getting old’ is something observed easily in in vitro cell culture treated with ‘differentiation enhancers’). This is just a 1+1=2 logic since it nowhere says that it speeds up cell division. It’s also the accelerated differentiation of cells which causes teratogenic effects. Differentiation is like job specialisation including school/apprenticeship: If your kids take magic drug X to become an expert in field this or that earlier doesn’t necessarily mean that they live less long or that population will go extinct earlier, it just means that you can save tuition.

[Pharma]

EVchem said:

…Have you ever prepared any emulsions with this?

Yes, during my PhD. More precisely a micellar solution, see THIS publication, section ‘Measurement of IL-1β maturation and secretion’.

Very easy to prepare since it’s self-forming mixed micelles. Emulsions (= same principle but way higher %) which I tried at home weren’t very nice, though ;( .

Best way to turn ascorbyl palmitate into its salt is by dissolution in methanol or ethanol, followed by neutralisation with NaOH or KOH, and finally evaporation of the alcohol. Micelles can be prepared without evaporation since the amount of alcohol is comparatively small, emulsions however…

[Pharma]

@EVchem ascorbyl palmitate, not phosphate . ‘t was a typo by @MarkBroussard.

[Pharma]

ngarayeva001 said:

Beeswax is not an emulsifier…

…Oils don’t do anything good for hair except for making it greasy and heavy. Oils are added at 0.5% maximum for claims only. Bottom line: hair needs cationics and silicones, not oils and butters.

Beeswax can easily be turned into an emulsifier by mixing with small quantities of alkaline substances, shea butter can’t (unless you count saponification) . Shea butter is an emollient also for hair though I doubt that waxes are.

Depending on hair type (e.g. African hair type), such oils and butters can be used at high % (with or without cationics/silicones) as ‘nurishing’ conditioners without making hair greasy and they might even work better than pure cationics & silicones. Sure, they make hair heavy but that’s not always a bad thing. If you haven’t noticed, many conditioners also contain fatty alcohols; that’s, at least on hair, simply a less greasy form of oils/butters which is better suited for ‘European’ hair (dunno about Asian hair and it’s requirements).

[Pharma]

Dang, I can’t find the information we’ve got anymore, it was from this summer about latest data regarding birth defects. Official sites and up-to-date go-to pages such as embryotox.de still have retinoids listed as no pregnancy for 1 month post therapy. It’s not the compound which stays longer than that in the system, it seems rather like an effect on gene expression which shows some sort of ‘reverberation’.

The other point is a concern which has been raised regarding the rejuvenating hype and not just retinoids: When your cells divide, they cut off a little piece of the telomers (end parts of your chromosomes). Once the telomers are used up, the cell can no longer divide. This means, at least in theory, boosting cell renewal uses up the body’s inherent repair system or in other words, you get older faster. But that’s AFAIK just an educated guess which hasn’t been proven in real life but seems to me as if it could be true.

[Pharma]

You could make sodium or potassium salt from it and that use as anionic emulsifier which spontaneously forms micelles above ~35-40°C.

[Pharma]

Yea, brightening complex, that’s what my shrink diagnosed! Told me that I’m having a brightening complex cause I’m under the illusion of being brighter than everyone else :smiley: .

Tretinoin is a prescription drug here around. It sure does a great job but, at least the oral form, has a very long lasting effect causing embryonic developmental disorders which require up to 5 years post treatment to fall down to a normal level ;( ! That’s especially brutal since most patients taking it are teeny girls which, for a fair part, are likely getting pregnant in a few years.

The effect on skin might be like ‘live short and intensely’ because of accelerated cell renewal = look like 20 for the first 40 years and for the rest more like 200.

[Pharma]

A spoon? Now that right there might be the answer to your issue . Use the blender in the beginning and stir at low sheer (manually if you want to) until cooled down.

Sour smell? Not that I know how it smells but I imagine it shouldn’t be sour. Ask someone else!

[Pharma]

Isn’t THIS the ‘facts sheet’ and THAT the therein cited publication?

Weird that they name it saccharide isomerate since, by definition, it’s not a saacharide isomerate but a modified exopolysaccharide… Also, it’s strange that the publication which determined the molecule’s structure mentions ‘use as cosmetics’ but they didn’t do anything cosmetics related. Also, they did state that it’s a linear polysaccharide and not a word about folding or receptor interactions…

Anyway, it seems as if that molecule ain’t synthetic honey as the name implies but a marine polymer.

[Pharma]

I’m not suggesting anything for your purpose, I’m simply stating that there are other possible options. The difference is that some of these options will not perform the same as the original formula.

It’s weird that benzocaine is in solution first (PG isn’t a bad solvent for it but it’s susceptible to dilution with water) but then form crystals once emulsified only in the larger batch. How much did they upscale?

[Pharma]

mhart123 said:

…feminine care…

…they are having trouble scaling it up…

…if you could recommend any resources that would be beneficial for formulating pharmaceutical applications…

Feminine care? Benzocaine is not something to be used in a ‘care’ product, it’s a pharmaceutical drug. For what exactly do you use 20%? Laser? Epilation? Tattoos?

What kind of trouble? Why isn’t it working or what’s failing?

A resource that would be beneficial: studying pharmacy? If you’re fluent in German, the Neues Rezeptur-Formulatorium is a great resource. I don’t know any English sites/books except USP and BP.

[Pharma]

Your oil phase is about 20% and your emulsifiers make up about 20%, that’s more emulsifiers than you’d usually need. Your oil phase is likely solid and may not work properly: Use less wax or softer wax and use high sheer to produce very fine droplets or switch emulsifiers to obtain a lamellar system which would work better with such high wax content. With all those PEG-based emulsifiers and a solid oil phase, your product should be super stable if/once you manage to get it to emulsify properly. How do you prepare it step-by-step?

[Pharma]

Emulsifying wax NF should be electrolyte tolerant and has a relatively long chain . But using either of the two proposed ones in addition might actually work (try and see).

Magnesium oxide will form magnesium hydroxide in water and this is alkaline. Neutralising it will result in a soluble magnesium salt. Since magnesium ions are usually the culprit, using magnesium lactate or the like is pointless unless one were to use a cationic emulsifier.

[Pharma]

There are many publications with regard to surface charge and emulsion stability, search for the so called zeta potential: If you really want to use surface charge as a marker for stability, then you’d have to use equipment which measures said potential (for example a Zetasizer -> charge determination to estimate stability) or do so indirectly via particle size and size distribution (with for example a Lumisizer -> size/stability determination as an indicator for zeta potential).

Since most particles tend to have a slightly negative zeta potential, adding an anionic surfactant more easily results in a highly negative potential and hence it’s more easily to get a higher stability. On the other hand, adding a cationic surfactant will not as easily give a positive enough potential for increased stability. In addition to that, anionic surfactants often have a ‘hard’ charge = concentrated on the surface = higher (negative) value of zeta potential whilst cationics are generally ‘softer’ = diffuse charge = lower (positive) zeta potential. This obviously favours higher stability in the former case.

Furthermore, charge is just one of several effects which may be used to increase emulsion stability and it only works well with micelles and somewhat with cubic and some hexagonal phases (though these may not adequately be measured with a Zetasizer) but not with lamellar or inverse phases whilst several other effects do work there too.

Bottom line is, depending on the emulsion type, imparting a charge to the outer phase of lipid particles is highly correlated with increased stability and is a simple physical effect or galenic law. As a rule of thumbs, an o/w emulsion with a zeta potential of greater than + or - 60 is regarded as very stable. A lower zeta potential (nearer to zero) requires additional measures such as addition of PEGs (steric hindrance), smaller droplet size, or a water gellant to keep oil droplets from fusing or at least reduce speed of fusion. Another approach is to switch emulsion type for example to a lamellar or ‘liquid crystal’ phase.