Bill_Toge
Forum Replies Created
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a quick and easy test would be add enough acid to the product so the pH drops below 4; if the product has carbomer in it, it will become very thin
a more rigorous test would involve HPLC-MS (to separate the cream into its component parts, and identify any polymers), followed by IR and NMR (to characterise the component parts)
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if some bottles from a given batch fail and others don’t (which is how I read your post), that suggests the product is unevenly mixed or otherwise non-uniform
also, when you say “Incubate the water phase and oil phase ingredients for 20 mins in separate beakers”, do you check the two phases are actually the same temperature before mixing them together?
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they might be marking it up for small orders; Sensient are a large company, and they may well prefer to sell products in fairly large quantities (we’ve only ever ordered their dyes through an agent, and their rates are much more reasonable)
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@Doreen81 and those figures were obtained at 25°C: if you want it to pass stability tests at low temperatures, you’ll need more PG than that
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my money’s on salicylic acid
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it won’t make any difference: denatured alcohol is almost entirely ethanol, with a small percentage of adulterants added to make it undrinkable
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ceteareth-25 has negligible vapour pressure unless you heat it well over 100°C, or spill it on a hot surface
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the second one (the rotor/stator mixer) is a more widely used design, both on the lab and plant scale; it’s similar to a Silverson or Greaves mixer
it’d be total overkill for making shampoos, but it’d work well for making creams, lotions and conditioners
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it’s an oil at room temperature, so it’s most likely added for lubrication
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this depends very much on what criteria you use to judge whether or not a given level is too high
from a technical point of view, your formula will certainly do the job it’s meant to do, and the lanolin/shea butter/babassu oil won’t harm it at all
the only comment I’d make is that Phenonip is unnecessary, as the formula contains no water and won’t sustain microbial growth
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it depends on what kind of fragrance you’re adding, and where you’re sourcing this fragrance from
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@mikethair that is shockingly poor service, notwithstanding the fact that Crotein HKP Powder is a stock item over here
if memory serves I believe @Chemist77 is based in India; you may have better luck contacting Croda’s agents in that part of the world
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the general rule I use is to round percentages of materials to their first two significant figures, and work everything else out from there; the water acts as a variable remainder which serves to make up the formula to 100%
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@myalcin have you done freeze/thaw tests as well?
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the Cosmetics Regulations 1223/2009 EC apply to all cosmetics, regardless of where they’re made
no approval is needed to place products on the market, but you do need to register your product(s) on the Cosmetic Product Notification Portal, preferably before launch
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@myalcin in which case, there’s a high chance it’s destabilising as it cools; the solubility of the emulsifier(s) in water reduces as the product cools, which in drastic cases can lead to the water phase becoming physically detached from the interface
my first suggestion would be to find the drop point of the oil phase, and form the emulsion 5-10°C above that instead of at 80°C
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what temperature are you forming the emulsion at?
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the flash point is the temperature above which a substance can spontaneously ignite: the vapour pressure is a measure of how readily it will evaporate
having said that, from personal experience, I’ve never had an issue with benzyl alcohol at that kind of temperature
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@mikethair can you source materials from Croda? in my experience, they charge significantly less than any of the prices listed above for their hydrolysed proteins
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if the reaction product doesn’t have an INCI name, or a CAS number, or any other formal identification, your best bet is to list it on the label as Potassium Hydroxide and Hippophae Rhamnoides Oil: i.e. the starting materials of the saponification reaction
by doing that, you also avoid the issue around the fact the exact quantity of reaction products is unknown, and possibly variable from batch to batch too
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Microbiological Solutions Ltd. and Advanced Development & Safety Laboratories in the UK offer this service; don’t know about the cost though
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the other critical factor is the temperature at which your emulsion is formed; it needs to be formed at as low a temperature as practically possible, or else it’ll destabilise as it cools
try melting phase A, cooling it, finding the approximate temperature at which it sets, then forming your emulsion 5-10°C above that temperature
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if the ingredients list for Brylcreem is accurate, chances are it’s manufactured using a very high shear mixer (e.g. Ultra Turrax) or a colloid mill: your problem sounds very much like the droplets of the dispersed phase are not small enough to guarantee stability in relatively extreme conditions
also, lanolin alcohol can help emulsify water into oil - it doesn’t work as a primary emulsifier, though
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what you need is another non-solvent liquid of some kind, e.g. propylene glycol
technically speaking, when guar gum and similar polymers are premixed in glycerine before being added to the batch, they are said to be dispersed in the glycerine rather than dissolved in it
the polymer doesn’t start to hydrate until it’s mixed with water, and dispersing it in a non-solvent liquid slows down the rate of hydration and gives the operator greater control over the process
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my best guess regarding batch #35 is that its drop point is close to the ambient temperature of your work space, and it’s transitioning between solid and liquid as the temperature varies through the day