Pharma
Forum Replies Created
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Metabisulphite, if allowed in cosmetics (dunno, really no idea) and if not concerned about it allergic potential, is great since it reacts with oxygen and turns your product oxygen free = pretty darn stable regarding degradation of antioxidants.
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Tetrahexyldecyl ascorbate is kind of astonishing but for the rest: antioxidants are meant to reduce other substances and become oxidised themselves instead, it’s what they do. The trick is to start with something that doesn’t require reduction i.e. which isn’t already oxidised. If it still happens: get rid of oxygen. This can be done by mixing in vacuum and/or by using degassed water (one of the handy things you can do with an ultrasound bath). Furthermore, but I suppose this is already the case, avoid alkaline pH.Ubiquinone can be reduced by ascorbic acid and likely by BHT, the resulting ubiquinol is very readily going to oxidise back. It’s also slightly reactive to nucleophiles such as free -SH and some -NH2 groups (especially the former is a rather unlikely case in cosmetics).
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Aziz said:Does it has H₂S like odour or worst ? Will Tea tree oil enhance its insects repelling job ?
Smells spot on like a billy goat
. Capric, caprylic, and caproic acid have their name from “capra” which is italian/latin/greek for goat because these fatty acids are constituents of glandular secretion of goats. -
If you want something very close and be on the safe side; sure, switch it with propanediol (which has a better anti-microbial boosting capacity than glycerol). On the other hand, does 3% glycerol do anything at all in your formula?
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Gold nano-particles are of great interest for drug delivery/pharmaceuticals (i.v., jet injection…) but the used particles aren’t made that easily as common “colloidal gold” and they’re neither coated by simply mixing stuff in a blender.What exactly happens with the particles, I don’t know… they’re likely going somewhere and just stay there till death??? Unlikely to happen in a topical product.
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Capric and lauric acid would be better insect deterrents (see for example HERE) than myristic acid but you might have to up the % . BTW capric acid stinks and you won’t just get rid of parasites but also of all your friends! :smiley:
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What exactly is in your cationic cetostearyl alcohol to render it cationic?In theory, anionics (soap) and cationics are incompatible but that’s just the theory. In practice, it depends…
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And there it starts with “mild”: According to my books, DHA is not mild but parabens are .It depends also on pH (regarding irritation potential and which preservatives can be used).
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What’s the pH of your formulas and are they stocked in transparent containers? Resveratrol is fairly unstable at neutral to alkaline pH and sensitive to light.As @ngarayeva001 mentioned, NAG and niacinamide are more stable and don’t readily oxidise.
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Sorry, nope (I’m not a fan of pegylated stuff).
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Lactoperoxidase is an animal enzyme. A Pubmed gene bank search reviled that mostly mammals have it but also some crustaceans, sea urchins, and insects such as Asiatic honeybees, aphids, and bed bugs.As far as my knowledge goes, plant “milk” is a colloquial term for latex. Latex, no matter how much it looks like milk, has nothing to do with milk. Also, milk just gave the enzyme its name due to its high content therein. Why someone would use plant “milk” and sugar to isolate this enzyme from bees evades me.Sure, genetically modified micro-organisms could express it and then it would be considered vegan but also GMO.
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Ah, you mean 10 and 5 % of a dilution! Makes more sense now.If you want to add those, be my guest, there’s nothing special to consider with gold and platinum.
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Purpledusk said:…I meant 10% gold and 5%platinum =15% …
That means 10 grams gold and 5 grams platinum in a 100 g jar = 500.- $ for the gold and 150.- $ for the platinum (which is currently cheaper than gold) = 650 $ just for the metals and your jar will be comparatively small considering the hight density of said metals
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What is oil A, B, and C?
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Forgot to mention (thanks @chemicalmatt for the reminder): Silver chloride is insoluble and inactive. Your greatest enemy you’re highly likely to encounter is salt (sodium chloride) since it is a very common contaminant. If you’re going with 15 ppm silver ions, ~7.5 ppm salt will annihilate any effect (except the claims).If you’re really adding 15% platinum, then your cream will probably be i) the most expensive on earth and ii) be the only super expensive cream which really deserves the price tag. You might consider adding just 15 ppm (=10’000 times less) for claim reasons. High amounts of colloidal gold and especially platinum are likely to give your cream an ugly grey hue. If you want golden sparks, add plated gold .
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Or they sell it under a synonym?Myristyl myristate is similar (not the same, though!) whilst for other applications, waxes can be used as replacement.What is the reason you add cetyl palmtate? What does it do in your lotion? What would you like your lotion to be if you could choose an improvement? What is not acceptable as a new effect?
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Probably it’s just so little water that it’s self preserving due to low enough water activity?
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Get a chemistry degree and a lab cause it’s not that easy. If you are looking for the easy way, get shark oil, a reverse phase MPLC, hydrogen gas, Raney nickel and a pressure tank.
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IMHO HLB is a nice to have but not a must have. Knowing the HLB of an emulsifier can be helpful if you stumble upon a problem and might explain why you did (however, it doesn’t necessarily tell you how to solve the issue).The HLB system works better when dealing with “pure” substances (such as the above mentioned Tweens and Spans) rather than mixtures (such as Xyliance, decyl glucoside, or polyglyceryls) and is most helpful in o/w emulsions which aren’t particularly stabilised with gellants. It does however work with anionic too, only the original HLB system isn’t made for those . I haven’t come across any helpful tool to predict HLBs for glucosides and polyglycerols. These are purely obtained by measurements and hence tend to deviate with different oil phases.
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Could you define “prilling”? I do know that word in a different context which doesn’t make any sense in your case and my dictionary isn’t of any help either.If you mean formation of small crystalline clusters: cocoa butter shows that in pure form and is said to not do it in mixtures although I’ve learned that it still does in some mixtures. One trick there is to incorporate it at 31-35°C and use low shear during cool down (some say only 30-32°C but this is likely borrowed from chocolate making, so is the advice to add a small amount of solid/cold cocoa butter at <30°C during the cool-down stirring phase). Another one is to use substitutes such as mango kernel butter.
The problem with cocoa is the different crystal forms of which only one is stable. Heating cocoa >35°C melts the stable gamma form completely and it takes a long time and low temps (<20°C) for it to re-crystallise. When it does, chances are high, that it forms those small clusters. Heating just enough to visually melt it without melting all crystals results in rapid re-crystallisation with an even distribution and hence a smooth appearance. The addition of cold cocoa butter during cool down does basically the same (the term would be “seed crystal”).
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It’s an emulsifier with high water holding capacity and it’s “sebum-like”.
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Specific gravity comes from measuring the caustic solutions with a pycnometer and is directly linked to concentration.
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True colloidal gold and platinum are stable no matter what. Colloidal and ionic silver are highly susceptible to UV light and oxygen and ionic silver does potentially reduce to metallic silver in the presence of certain antioxidants and/or other ingredients.Do not use Leuconostoc or other protein containing ingredients because they inactivate each other.
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Depending on what you want to do, stearate salts can be part of an HLB calculation. Just because they are negatively charged doesn’t mean they don’t have an HLB. They may however be out of the original range which, due to the arbitrary definition by Griffin, the inventor of the system, is set at 20. The HLB system has since been evolved, alternate formulas without an upper limit are available like Davies’ approach, which is the main one used in pharmacy, or even computer models (e.g. add-on for MarvinSketch). Hence, HLB values above 20 are absolutely possible and can be used for calculations without limits. Because stearate salts aren’t, from a practical point of view, fully dissociated like SLS, they would even comply with Griffin’s method. HLB values for salts such as SLS, because of near absolute dissociation, have to be determined using alternative biphasic systems. Remember, the HLB system is based on observation and the original formula was deduced from practical experiments (hence the restriction to emulsifiers which were originally used). But then again, half the originally published HLB values weren’t even calculated but only experimentally determined. Most HLB values of today’s emulsifiers are determined the same way. Depending on the model used, different values can be obtained.There is no practical application in cosmetics for final HLB values above 20 or rather, there is no noticeable difference between a product with an HLB of 20 and one of 40. If a combination is used which has an HLB below 20, there is no reason not to apply the same formula for co-emulsifiers with an HLB >20.One limitation of calculating HLB values for stearate salts is their pH dependency in acidic formulas.
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Which emulsifiers do they use and what else do they add? Their product might be what’s called a D-phase. This is cool technology but it results, if the name tells the truth, in a microemulsion and that, I can imagine, isn’t very much fun in a bath since you won’t see that there’s actually oil in the water. Microemulsions are transparent/translucent with a bluish shimmering (Tyndall effect) and skin doesn’t feel nourished afterwards (the oil droplets penetrate skin way better than common oil drops which remain mostly on the skin).BTW since you’re going to do a few changes: If you want to combine two emulsifiers, theory has it that you’ll get a better stability for o/w emulsions (the final bath) if only one is an oleate . It might no longer be a cold process or use Tween 20 or 60 instead of 80.