Pharma
Forum Replies Created
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In theory there would be a connection between ascorbic and ferulic acid… However, SAP becomes only ‘active’ within a living cell and therefore an in vivo interaction (ascorbic acid recycling oxidised ferulic acid) may or may not happen.
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The reason why cholecalciferol can not be a cosmetic ingredient:Vitamin A and vitamin D are the only two vitamins which are not
co-factors in enzymes and/or antioxidants but, in their active forms,
bind directly to promoters which ‘activate genes’ and produce more
effect the more you take and don’t level off at the limit given by the
physiologic concentration of corresponding enzymes.Similar to most B vitamins which require activation, vitamin A is
commonly applied as precursor (retinol or retinyl esters) which, to some
degree, can be activated by all living cells and organs. Vitamin D in
its common form cholecalciferol needs to be activated first in the liver
and then the kidneys in order to become biologically active. This means
that topically applied vitamin D will not show any topical effects like
in the case of vitamin A but has to penetrate skin, get assimilated,
pass through the whole body to become active, and finally exert its
function systemically (in the whole body). That’s the main reason why
biologically active vitamin D derivatives are used in topical products.
To my knowledge, cholecalciferol has no topical effect and those would
be the ones you need for claims. The instant you claim metabolic
activation, your product is a drug (or nutrient supplement) because it
relies on a full body circulation and lacks skin targeting. -
Vitamin D is a partially synthesised and highly active compound which, back in the day, was often not pure but just an ‘activated concoction’ or it was sold in diluted form for easier and more precise measuring. Hence, quality/purity is traditionally expressed in international units instead of grams (1 ug = 40 IE). Yours would be 0.25% pure cholecalciferol.
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Oladoo said:Does this mean anionic surfactants work better at lower pH?The job of a surfactant is usually cleaning and that does not include binding to host molecules. So, no, the publication only illustrates the interactions of surfactants and hair/skin. Cleaning commonly refers to reduced surface tension and mechanical removal accelerated by surfactant-dirt interactions and, to a lesser degree, reducing dirt-hair/skin interactions. True, surfactant-hair/skin intaractions will play a role there and so does swelling but that’s probably the least interesting effect when it comes to cleaning.Though when you’re talking hair conditioning, things look different. There, the term surfactant is usually not used in cosmetics even if the employed molecules follow the exact same rules and will show the exact same interactions
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Never worked with C12-15 alkyl benzoate… it should be quite similar.Coco-caprylate/caprate is fairly similar (not similar enough for my taste), has a viscosity, spreading etc in the same range. Not quite as ‘good’ as IL and hence, I like IL more. It feels less greasy and comes with the perk of a short branched side chain.The others all have higher viscosities, lower spreading, penetrate/dry not as fast, and are less polar. Even coco-caprylate/caprate isn’t really polar compared to IL and alkyl benzoates.I would guess, from a theoretical musing, that a blend of C12-15 alkyl benzoate and coco-caprylate/caprate would come closest to IL.Becaue I have more coco caprylate than IL in stock and the former is less expensive too, I use it as an IL substitute during trial formulations (notably, coco caprylate has a lower viscosity and higher spreading than coco caprylate/caprate and hence comes even closer to IL… nonetheless, I can still feel a difference).
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Lukman88 said:…- virgin coconut oil 80%- water VCO 10%- polysorbate20 5%- perfume 3%- Preservative 2%…
Looks weird and unstable… Raises some questions: Why 10% water in an oil-based formulation? Why a o/w emulsifier in a w/o emulsion (you could do an o/w with just 10% water using a different emulsifier but that would result in a very viscous gel)? Which preservative and why 2%? Where’s the whole rest of the ingredients needed for a stable w/o emulsion? Why do you want a polymer, what should it do? Why do you ask for alcohol? Explain your Q ‘Can the emulsifier last?’. How are you going to spray virgin coconut oil in winter or when the A/C is on (coconut oil solidifies below ~24°C)? 3% perfume… you seem to love perfumes. Have you ever made cosmetics before? Ever read a book or the like about DIY cosmetics and the basic principles of emulsions etc.?
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Collagen and elastin fibres need to be in a precise orientation in a specific place in order to work. It’s not like the ‘random gel’ formed by hyaluronic acid. Sure, HA in theory has a very fast catabolism but somehow (I suppose due to its tremendous water binding) does degrade slower than pure proteins such as collagen and elastin. The latter would likely just form some sort of lump in the connective tissue without doing anything to the skin above.
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It’s a fast process, you don’t have to wait.
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PhilGeis said:…are among the contaminants of many household and industrial products - minerals/salts themselves are often the source…
Good you mention this, it completely skipped my mind. Totally makes sense especially regarding sea salt. Saline lakes and salt evaporation ponds are home to a plethora of ‘weird’ microbes such as halobacteria (hence the red colours) which aren’t found elsewhere… as it seems with the exception of the unsuspicious salt shaker in everyones kitchen. Hmm… in hindsight it sounds so obvious (*feeling stupid right now*).
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+20% salt only allows growth of extreme halotolerant and extreme halophilic microbes (CLICK) which are usually only found in environments naturally very high in salt. Hence, there is a very high chance that you won’t have microbial growth (however, 20% salt doesn’t mean contaminating microbes will die in there) especially if you were to cool your batch or boil it before ‘canning’.
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Let’s call it gas exchange. Better occlusives are silicones which allow for gas exchange whilst keeping water in the skin.What breathes are for example microbes aka skin flora which can tilt under anaerobic conditions in favour of more prblematic germs.
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SugarHouse said:But why do they call it ‘Fragment of Human Type I Collagen’ if it’s from a plant?GMO: You take the DNA sequence for example of a part of human type I collagen and implant that into tobacco cells.So… given that vegan is more of a label and a pilosophy than ‘noting from animals’ let alone ‘what’s best for nature and the planet’, it’s your decision whether or not you want to use it. Given the not always logical restrictions of veganism, using GMO of the type where hydroponically grown plants were violated against their will to express proteins of their archenemy could absolutely be okay. It’s just a plant which does weird things it could naturally never do.
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Why do you opt for a solid acid which is also one of the least oil soluble ones amongst cosmetic ingredients?
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@Pattsi One book? Maybe I can dig out the review my doctorat supervisor has published… there are thousands of papers on curcumin. Long story short, curcumin is too lipophilic to be of any use beyond topical effects (1-2 cell layers deep). Else, it would be a silver bullet.As far as I know, thetrahydrodiferuloylmethane is just a colourless substitute which looks good on the label.I don’t know anything about cassmunarin. Judging from its structure it’s even more lipophilic… I’d love to try it as spice, send some rhizomes pleeezz!
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If I remember correctly, genetically modified Nicotiana sp. are used to express several foreign proteins and peptides. When I first read about this I was WTF… I have no clue why Nicotiana and not microbes which are usually used for this kind of work.
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If you post yourself smashing an egg onto your head on TicToc it might have a real effect :smiley: .
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ariepfadli said:Depend on your pH meter model, if it also have tds meter then you can use it.It’s a simple calculation from ppm to TDS: ppm = TDS .Converting EC to TDS is nearly as easy or just use THIS.Good deionised water can have the same EC as distilled water… both are fine for cosmetics. Besides, distilled water is seldom distilled these days .
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I don’t know about SLES but identity determination according to pharmacopeias of longer PEG chains than the 2 in SLES is actually determined using FT-IR.You could check out pharmacopeia guidelines for SLS and SLES… some are identical because they determine the sampe part of the molecule. Maybe a colour reaction in solvents could be feasible?
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Sponge said:@Pharma, so repulsion falls under two main categories, steric and electrostatic, right?
What are the other [main] forms of stabilization and can you some them up in an equally beautiful paragraph?
Repulsion is mostly caused by electrostatic repulsion (measured as zeta potential in micellar emulsions), steric ‘don’t touch’ is called steric hindrance and works like porcupine quills versus predator.In case of emulsifiers, the former is achieved by using anionic or cationic emulsifiers whilst the latter is usually achieved with long hydrophilic head proups (e.g. PEGs, polyglyceryls). Hydrophobically modified polymers, gum Arabic, and milk proteins, oleosomes, modified silica, and other Pickering emulsifiers etc. also work, under others, by steric hindrance.These two stabilising strategies are mostly preventing oil droplet coalescence and partially also flocculation. Increasing viscosity of the outer phase (and the inner regarding coalescence but not flocculation) also helps and might be the number one used in current cosmetics.Ostwald ripening, a ‘slow motion’ instability which can easily go unnoticed in preliminary testing, is prevented by incorporating something soluble in the inner phase which is insoluble in the outer.Creaming and sedimentation are usually prevented by increased viscosity of the outer phase. Matching densities would also work.Most of these effects only work well with micellar emulsions and are usually only discussed in this context in text books. Many modern cosmetics are ‘ugly’ unpredictable messes of mixed type emulsions… called lamellar networks, alpha gels, or liquid crystals. Such structures often make up one part of the emulsion and are, combined with gelling agents, responsible for stability. Steric hindrance does work here, electrostatic repulsion partially works, Ostwald ripening and Pickering emulsifiers are of minor or no concern here. Matching densities and viscosity of the inner phase are also negligible or unpredictable (under others for the simple reason that there is not one inner phase).I know, not an equally beautiful paragraph but hopefully helps nonetheless. -
@Bill_Toge My first thought was also AMP but then I realised that it’s in amide bound form and should be pretty stable… should at least in theory.@Iwana Do you have a picture of the yellow to get an idea of how yellow you’re talking?There’s nothing in your product which should turn yellow but should and does are two different things when it comes to more or less natural multicomponent mixtures meeting water, oxygen, heat, and time.
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PhilGeis said:…Pseudomonads have plenty of esterases.
This would result in free caprylic acid and, at least in vitro, caprylic acid shows some antimicrobial efficacy and reduces biofilm formation. 🙂
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Margaret said:I use 0.26% sodium benzoate (mentioned above), but I left it out of the formula. Sorry for the confusion ????. I was thinking that since sodium benzoate is not effective at less than pH 5.5 why is it used by toothpaste manufacturers?
…Sodium benzoate is most likely not active in your product.Calcium carbonate is poorly soluble in water and very poorly soluble in polyols. That’s why it doesn’t increase pH much. Diluting it with distilled water before measuring with a paper strip would be wise, these strips do not work properly with suspensions of pH active compounds (however, dilution will likely increase pH). Calcium carbonate isn’t reducing water activity to any useful degree. Even with a 5:2 mix of glycerol to water (roughly 70% or aw 0.66), your water activity is still in the range of ‘some microbes can grow in there’. Sure, it’s in a range where no pathogenic microbes can grow and only extremophiles dwell (not all of these like alkaline conditions)… If you want to be on the really safe side, aim for 80-85% polyol content, add salt (several of the possible survivours don’t do well in brine) or use a pH independent preservative (maybe, though you’ll have to test, essential oils and the like could be enough to give it the last kick).I would wager that you can easily switch back to a blend of glycerol plus sorbitol (xylitol would be even better in a toothpaste), the minor increase in water activity will not reduce self-preservation to a noticeable level.For personal use = short shelf life, your formulation looks safe enough to me. -
You’re welcome :smiley:Darn, I think I have OCD… there’s a typo in my citation!…it, say helical, structure requires… should be …it, say helical structure,
requires…Is this just exceptionally nitpicking or am I going Mac nuts? LoL!
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From where I stand, I’d say that Tg (glass transition temperature ~ melting point) in cosmetics would/could only have an impact in production processes of nearly to completely anhydrous phases or emulsions… and that’s exactly why I prefer xylitol over sorbitol. Does I feel or perform better in a cosmetic end-product? I don’t have the impression.