Pharma
Forum Replies Created
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EHG is said to be active above 0.1% as booster for example for phenoxyethanol. Alone, you’d have to use it well above 1%. Meaning, EHG in a blend like Euxyl 9010 will be limit if sticking to the EU regulation which @PhilGeis mentioned. Given that it’s not too problematic even at 5% or higher (contact allergies are infrequent but we will, most likely, see more in the future due to increasing usage of EHG) and it also acts as emollient and humectant, inclusion at more that just 0.1% seems reasonable. Compared to other, similar compounds, I’d aim at 0.3-0.5% or even more but be careful because higher levels might in some cases interfere with emulsion stability and/or viscosity.
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Ethylcellulose and some polyacrylates (carbomers and especially acrylate/alkyl acrylate crosspolymers) should work. The former is more ‘natural’ but may be susceptible to degradation by cellulases (should you add those particular enzymes to your product).
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Wash them with soap and whip down with 70% ethanol before use
.Sterilising them means you’d have to get a very clean room and a sterile work bench (=laminar flow) to keep them sterile. Also, you’d have to gamma-irradiate or sterile filtrate your ingredients too. Most cosmetic manufacturers don’t have/make any of that and don’t need to After all, your products contain preservatives for a reason (or two). -
Why do you need sterile equipment?
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GLDA has one huge advantage over EDTA: It’s biodegradable, not super fast and only after acclimatisation of or inoculation with corresponding microbes but that’s already better than EDTA. On the up-side, GLDA’s not so good chelating power makes bound metal plant available. In hydroponics and agriculture but also when accumulating in nature, this is a huge plus point. Synthesis-wise, it can be obtained more readily from renewable resources with less dependence on petroleum chemistry and, given that it is intended as more eco-friendly alternative to EDTA, a greener production chemistry is part of the sales pitch. On the down side, EDTA just works better and more efficient in a cosmetic product (if you’re the the type of ‘screw Greta, climate change is a problem the next generation should deal with’ person, EDTA is sadly still the way to go if you want to go better safe than sorry).
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How you obtain/synthesise xylitol doesn’t matter. In the end, it’s always the absolutely same molecule called ‘xylitol’. What can be different are the residues and contaminants but with a reliable/responsible manufacturer this isn’t of any concern.
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Phosphate is certainly no concern. Phthalic acid on the other hand… not just that phthalates (esters of phthalic acid) have a bad reputation but there are alternatives such as malic, citric, or succinic acid paired with a strong base such as NaOH or KOH
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You mean elemental sulphur? Carbon disulfide and toluene come to mind. Other hydrocarbon and aprotic solvents and solvent mixtures with ionic liquids may also be used depending on the amount you required dissolved.However, these solvents are not to be used as cosmetics!
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Pattsi said:…
For crying out loud, why would you have to mention China in all posts.Because she doesn’t know that many chemicals and most active pharmaceutical ingredients on this planet are actually manufactured in China?
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GLDA is about 10% heavier than EDTA and the graph would look even more extreme were it in mM instead of ppm .Anyway, such differences are not only due to binding affinities but a several other factors such as pH dependence, solubility of free and complexed chelates, assimilation, cell wall interactions, biodegradation, competition with microbial sequestrants, and non-chelate effects.Overall, the graph is biased because it highlights the very narrow range of 1000 to 1400 ppm where there are differences. Besides that, it’s a very non-self-explanatory graph with chelate concentration on the x-axis and quaternary ammonium compound on the y-axis. Whatever that means… Maybe the effect (whatever effect that is, it’s not mentioned) is caused by precipitation of QAC-chelate salts?
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Can and should are two different pairs of shoes. Can = anything you feel happy with and which doesn’t kill the product or the consumer; should = the amount needed to preserve your product sufficiently. Phenoxyethanol has a quite well defined recommended usage level. EHG has too but as a multifunctional booster, you can basically add as much as you want, just don’t go below a minimum.
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Should work though depends a bit on the type of vitamin C derivative you intend on using.
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More chelate doesn’t actually mean a better action. Furthermore, apparent binding affinity depends on ionic strength of the medium, temperature and more importantly pH. Bear in mind that binding is reversible, free and bound metal are in equilibrium which means that said numbers refer to the ratio of bound versus free metal ions.But the most important thing to note is that the K numbers in that chart (stability constants, more correctly pK values) are log-scale, not linear. The metals of concern in a cosmetic product are usually Cu, Fe, and Mn with Ca only in certain products.Let’s take iron as an example and do simple 1+1=2 maths and ignore concentration effects and the rest: 25.1 v.s. 11.2 means a difference of roughly 14. To obtain the same amount of bound iron with citrate than EDTA, you’d have to take about 100’000’000’000’000 times more citrate than EDTA!I guess that should suffice as an answer .
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It’s not an official LOI and therefore it doesn’t mean anything. It might really be the correct order but I wouldn’t bet on it.
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Any guess wouldn’t be more accurate than the % range they already give. Only with testing or inside knowledge could one get a more precise %.
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@Graillotion EQ 65 is similar to BTMS. I don’t know whether or not it’s equally good at emulsifying silicones and/or squalane (which comes close to silicones in several regards).@Zink One reason to use BTMS and alike would be incompatibilites for example with cationic polymers such as chitosan.Given that most emulsions using non-ionic emulsifiers have a negative zeta potential by nature. This makes it a safer bet to add anionic co-emulsifiers which will further decrease the potential rendering the droplets more stable. Adding a cationic one will increase it and hence pass through the unstable range of -30 mV to +30 mV before hitting a high enough positive value to actually be stable again. Sure, if working with lamellar networks and liquid crystal structures as well as gelling agents, zeta potential may be less of a concern.
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Coco betaine and cocobetaine are the same whereas cocamidopropyl betaine is not. Both are amphoteric surfactants, the former betaine with one of the methyl groups substituted for a mixture of short carbon chains derived from coconut oil (likely mainly decyl and dodecyl) whereas CAPB is betaine with an aminopropyl chain instead which in turn is bound to fatty acids from coconut oil by amid bonds. CAPB should, according to empirical theory, be milder.See graphical illustration for chemical structures HERE.
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I don’t see any benefit in a 98% xylitol base toothpaste. Xylitol works to replace sugar and to reduce biofilm formation on enamel already at lower levels. Xylitol at high % or rather in water-free products shows a nice feature: if it dissolves in water, it cools down and gives a ‘freshness’ kick (best combined with peppermint EO). A good toothpaste should do more than that.A problem with corn cobs is that several countries grow GMO maize especially for feed & technical applications (e.g. cosmetics). Trees (at least the ones used for xylitol production) are never genetically modified. Hence, buying xylitol derived from trees will automatically ‘proof’ that you don’t sell GMO whereas traceability of xylite derived from corn cobs will be quite difficult (there’s likely not enough maize DNA in the final product to double-check for absence of GMO).On the other hand, many organisms/enzymes used for syntheses by fermentation employ GMO microbes or biotechnologically modified ones. This is usually okay because, as said, there is virtually no genetic material left in the product and the introduced genes aren’t of any concern (they are ‘natural’ and ‘common’). BTW many such modifications are usually indistinct
between genetical and biotechnological modification strategies and you’ll have a hard time finding out whether or not modified materials were used during production (that is, if they even used microbes/enzymes).Genetic modifications may or may not be approved by consumers… On the bright side, most consumers aren’t bright enough to know that much and will, at best, raise concerns with regard to potentially modified resources (e.g. corn) = go with birch, people love birch! :smiley:Apart from that, THIS article might be interesting. Sure, a bit overkill but still some nice insights (including which company/country produces xylitol from which resource). Most striking for me was that China uses corn cobs… -
As long as there is diffusion, order of addition won’t matter. Also, ‘monoprotic ions’ aren’t bound very strongly to clay minerals (which is generally a good thing here).Pre-wetting/saturating clays (or any other porous or ion exchanging material) with as many ingredients not serving as preservatives increases the chance that ‘unimportant’ molecules will bind first and hopefully stay bound = occupy the spaces where preservatives might potentially compete for. But then again, a liquid system is always in equilibrium. Given the long period of time a cosmetic product may lay around before being used up, equilibrium will be achieved and a preservative having higher affinity than whatever was originally bound will occupy its place.A workaround may be to disperse such materials in the oil phase to render them hydrophobic and hence hampering electrostatic surface interactions. Alas, this approach is not always feasible.Another strategy is to add ions with high affinity for clay minerals. Drawback here is that commonly used salts are quite efficient at killing emulsion stability, saturating chelates, or are unwanted for other reasons (such as aluminium, copper, iron, phosphate, or nitrate).Affinity series for cations: Al
3+> H+> Ca2+> Mg2+> K+= NH4+> Na+Affinity series for anions: PO43-> SO42-> Cl-> NO3-Sorry for the poor formatting, I don’t know how to format sub-/superscript.
A problem with this approach is that the ion affinity series neglect organic molecules and there is no straightforward formula to predict their interactions with clay minerals (unlike inorganic ions, they tend to bind without hydration shells which also makes them bind tighter). -
Only if I have to use mostly PEG-based emulsifiers. Else, the HLB system simply doesn’t add up (or at least isn’t better than an educated guess).
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IMHO what’s more important than the actual source of xylitol is the way hemicellulose is turned into xylose and then xylitol.There are mainly two routes which both start from hemicellulose either using corn cobs or a by-product from cellulose production (i.e. from wood treatment, most often birch and beech). Corn cobs are more frequently used in the USA, wood wastes are the common source in Europe.The first synthetic route is the older, fully synthetic one where xylose is obtained by acid hydrolysis followed by reduction using hydrogen gas and a catalyst. The more recent second strategy involves microbial fermentation for both steps. Notable, xylitol may also be obtained by each one synthetic and one natural (or vice versa) conversion step.Xylitol is an upcycled waste product from dirt cheep material usually used for soil amendments and the like which has now become a highly regarded sugar substitute from renewable resources. In the beginning, small scale (synthetic) manufacturing caused high prices, nowadays it’s maybe a mix of using slower fermentation and high demand/fame/marketability.Besides oral health benefits, no insulin secretion and only 40% calories compared to sugar, xylitol is as natural as many other artificial sweeteners and sugar substitutes but has the big advantage that it’s obtained from trash and doesn’t require too much additional cleaning and refining.
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Search for “cold cream” and not cold cream without apostrophe.Better in which regard?Environment/health-wise: What about everything? :smiley:Seriously, there is not ONE product which can replace every (positive) aspect of borax added to a cold cream but you can work around it. Use an anionic emulsifier (such as Castile soap, TEA stearate, or SLS/SLES) and add a preservative. For certain pharmaceutical preparations, both can be omitted. However, for more physical & microbial stability this wouldn’t be a wise decision.The buffering capacity of borax may or may not be an advantage. I never thought about substituting/mimicking this feature given that we don’t have a traditional cold cream based on borax (not to mention that borax has been banned a few years ago). If you like the higher pH of borax, you may adjust that with a base, saponify part of your oil with NaOH, or use traditional soap. I don’t quite see an advantage of a high pH unless you’re relying on soap instead of an ‘artificial’ emulsifier such as sulfates/sulfonates. Feel free to play around with other emulsifiers (non-ionic, cationic). In theory, low HLB emulsifiers would be the way to go but require higher % than SLS or SLES.
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We have some nice discussions here on CC about cold creams .BTW if you have to live by the sometimes biased, often poorly researched and outdated opinions of EWG because your customers love semi-reliable data by self-opinionated people who seem to like to draw power from influencing the masses… it’s your decision. Everyone chooses his/her own piece of the marketplace.What I don’t get is that you even dare using the word ‘borax’ in an non-negative context.Cold creams are simple and cover the bases from a pharmaceutical/health point of view. However, they are neither sufficiently stable for cosmetics nor ‘haptically viable’. More stable versions/formulations are available (again, use forum search bar) whilst most if not all cold creams from big corp out there are not cold creams in the proper sense but pure figments of marketing imagination.
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It depends on the type of clay. Several 2:1 clay minerals of the phyllosilicate group like montmorillonite and vermiculite have a high CEC and hence a high affinity for cationic ions, they act like cation exchange resins. Highly porous silicates (e.g. diatomaceous earth and zeolites) tend to adsorb (not absorb, that would be a misnomer) everything like molecular sponges and may, depending on many factors (like presence of cationic polymers), even have preferences for anionic species such as organic preservatives available in salt form (e.g. benzoate, sorbate, salicylate, anisate, levulinate…). Only a few minerals like kaolinite and iron-rich minerals have a noteworthy affinity for anions. Obviously, CEC and AEC are also pH dependent.Apart from that, the main issue with clay minerals and preservation is not or at least not solely due to loss of free preservative due to adsorption but the often high content of trace elements within these minerals which serve as bug food and/or overcharge the added chelates.
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HA is a polymer . High molecular weight HA does gel nicely if used at sufficient levels.Not knowing what formulation you have makes it impossible to estimate whether or not HA might be enough for the task.