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(Failed emulsion) BHA cream got weird seperation, plz help me out!
I have read and researched alot, but i still failed after a lot of attempts. Can anybody here enlighten me on how to fix it?
below is the formula:
- Water phase: (heated to 67’C)
+ water 70.6
+ edta 0.2
+ glycerin 2
- Oil phase: (heated to 69’C)
+ BTMS-25 4%+ Cetyl Alcohol 3%+ Jojoba oil 5%- BHA phase: (heated until dissolved)
+ 1,3 propanediol 10%+ BHA 2%+ HEC 0,4%- Cool down phase: (below 50’C)
+ EHGP 1%+ TEA 1.8%Direction: I heated water phase and Oil phase to 67-69’C, then i poured water into oil phase. Oh, i saw good signs of emulsion, after 5 mins of high speed stirring, i got the creamy cream. Then I had EHGP poured in the emulsion, it still worked fine until I added the BHA mixture (BHA, Propanediol, HEC) slowly into the emulsion. It became water-runny cream immediately, i freaked out and hoped my TEA would activate the HEC and got the cream thickened up, oh this was all in my imagination since the cream didnt thicken up, it even got separated between a white layer of thich bubbles (on top) and mild yellow milk lotion (kinda runny and at the bottom).Can anyone tell me how to fix this?
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12 Replies
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The final pH is around 3.8-4.0
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@Trng1122 Could you try removing your 1,3-propanediol (keep on mind it is a solvent, so emulsions can be destabilized by high amounts of it), adding your BHA by slowly sprinkling to the emulsion durong the cool down phase, and switching the position of your HEC to the water phase where it will swell freely?
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@Trng1122
First I’d try to keep the temperature of both phases (oil and water) at 70-75 °C in the emulsification step, and as was said, move the HEC to water phase, the heating will thicken the water phase and you won’t need TEA. Heat water up to 60 °C, add edta, glycerin and under stirring you can add HEC, 5 to 10 min you’ll have your HEC-gel.In fact, 10% of propanediol is waaay too much for your formula. I would try 4% or maybe a combination with ethanol (2:2:2 ratio).
Hope this can help you fix your fomulation
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BTMS-125 has positive ions ?
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BHA? Do you mean butylated hydroxyanisole or beta-hydroxy acid?The INCI BHA refers to the former, an antioxidant which should not be used at that high concentration. If you mean the latter: Which acid exactly (probably salicylic acid)? Adding TEA will only abolish an acids effect (but have no effect on HEC).Also, if you were to make an acid peel, why did you decid to go with a cationic emulsion? Sounds somewhat counterintuitive and is highly likely to kill the emulsion if you don’t use further emulsion stabilising co-emulsifiers and other fortifying tricks (and/or make sure that the acid remains dissolved exclusively in the oil phase… which it won’t given the amount of propanediol).Also, what’s the final pH? -
ketchito said:@Trng1122 Could you try removing your 1,3-propanediol (keep on mind it is a solvent, so emulsions can be destabilized by high amounts of it), adding your BHA by slowly sprinkling to the emulsion durong the cool down phase, and switching the position of your HEC to the water phase where it will swell freely?
Thanks alot, i did remove propanediol and switch to another solvent, HEC to the water phase (im too impatient to let it swell, only dispersed), and I made it, thanks again.
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marimaster_3991 said:@Trng1122
First I’d try to keep the temperature of both phases (oil and water) at 70-75 °C in the emulsification step, and as was said, move the HEC to water phase, the heating will thicken the water phase and you won’t need TEA. Heat water up to 60 °C, add edta, glycerin and under stirring you can add HEC, 5 to 10 min you’ll have your HEC-gel.In fact, 10% of propanediol is waaay too much for your formula. I would try 4% or maybe a combination with ethanol (2:2:2 ratio).
Hope this can help you fix your fomulation
Thanks for sharing, I made it heated between 70-75’C, HEC to water phase but it’s only dispersed until i had it poured in the heated oil phase. Everything is perfect fine but my emulsion got tons of bubbles in it, is it still stable?
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Pharma said:BHA? Do you mean butylated hydroxyanisole or beta-hydroxy acid?The INCI BHA refers to the former, an antioxidant which should not be used at that high concentration. If you mean the latter: Which acid exactly (probably salicylic acid)? Adding TEA will only abolish an acids effect (but have no effect on HEC).Also, if you were to make an acid peel, why did you decid to go with a cationic emulsion? Sounds somewhat counterintuitive and is highly likely to kill the emulsion if you don’t use further emulsion stabilising co-emulsifiers and other fortifying tricks (and/or make sure that the acid remains dissolved exclusively in the oil phase… which it won’t given the amount of propanediol).Also, what’s the final pH?
You guessed it right, i meant the salicylic acid. A fairy lady tell me that BTMS 25 is perfect for low pH, is it ok if i have cetyl alcohol (tried) or glyceryl stearate SE as co-emulsifier (not yet try)? You want me to switch to NaOH solution (instead of TEA)? Thanks a lot for recommending having SA dissolve in the oil phase, i switch its solvent and have it totally dissolved in the oil phase, and i got the cream (not even runny like water, i love the texture). However, the final cream got tons of bubble trapped in it, do I need to switch to another bladder or reduce the time of stirring bcuz I have the emulsion high-speed stirred like 7 minutes (with short pause between)?
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Replace your bmts 125 with non-cationic emulsifier.
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Don’t mix BTMS with glyceryl stearate SE if you don’t know what the ‘SE’ is (it’s often an anionic emulsifier which would be incompatible with cationics). A PEG-based emulsifier would work well, though.The choice between cetyl alcohol, glyceryl stearate (not SE), or both is up to your preferences regarding texture etc. At a low pH (where they turn nonionic), also lactylates and fatty acids can do. An oil thickening ingredient would be something I’d add if it were my product. Thinking of cetyl palmitate, a wax, or any other high melting point oil/fat/ester/hydrocarbon/etc.I have no idea why you want to add TEA or NaOH (especially at the mentioned 1.8%). Sure, if you have to raise pH because salicylic acid gives you a too low pH, there’s no issue with that… except that you’ll neutralise most of the SA and render it a useless electrolyte which might kill your emulsion. If SA isn’t dissolving well in water, now that’s a different issue (which in my opinion shouldn’t be solved by adding a base though that is, only at first glance, the easiest and fastes way to deal with it).If SA is in the oil phase, you might even omit pH adjustment completely and thereby get the full effect of SA without an uncomfortable feeling due to a low pH (especially if you don’t add any solvents to the water phase which might draw SA out of the oil and into the water phase). Sure, pH might be really low but the amount of SA causing that will be small and easily be compensated by pH active substances on your skin = not as irritating as the same % of lactic acid (water soluble AHA) at a pH possibly even 0.5 to 1 unit higher.Alternatively, you could substiture BTMS with stearamidopropyl dimethylamine (I think this blend might be patent protected, check if you’re trying to sell your creation). It’s an alkaline cationic emulsifier somewhat similar to BTMS but will react with some of the SA to form a composit acting as cationic emulsifier and water soluble salicylate at the same time (with SA keeping some of it’s activity compared to neutralisation with TEA or NaOH). However, you might want to combin that with more cetyl alcohol and/or glyceryl stearate and probably also with an approximately equal amount of an emulsifier having two alkyl chains such as distearoylethyl dimonium chloride (Varisoft EQ65) and/or a polyglyceryl diester (thinking of Emulium mellifera).Per @Dtdang‘s suggestion: A nonionic emulsifier with a large head group (PEG-100 stearate, polyglucosides, polyxylosides…) would be a wise co-emulsifier in your case. In general, nonionics should also work as main emulsifiers (many but not all are salt tolerant) whilst an anionic one will require some knowledge of its chemistry (not all work at low pH, go with sulfate/sulfonate/taurate/isethionate) and make for a great fortifying co-emulsifier in a nonionic base.
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Pharma said:Don’t mix BTMS with glyceryl stearate SE if you don’t know what the ‘SE’ is (it’s often an anionic emulsifier which would be incompatible with cationics). A PEG-based emulsifier would work well, though.The choice between cetyl alcohol, glyceryl stearate (not SE), or both is up to your preferences regarding texture etc. At a low pH (where they turn nonionic), also lactylates and fatty acids can do. An oil thickening ingredient would be something I’d add if it were my product. Thinking of cetyl palmitate, a wax, or any other high melting point oil/fat/ester/hydrocarbon/etc.I have no idea why you want to add TEA or NaOH (especially at the mentioned 1.8%). Sure, if you have to raise pH because salicylic acid gives you a too low pH, there’s no issue with that… except that you’ll neutralise most of the SA and render it a useless electrolyte which might kill your emulsion. If SA isn’t dissolving well in water, now that’s a different issue (which in my opinion shouldn’t be solved by adding a base though that is, only at first glance, the easiest and fastes way to deal with it).If SA is in the oil phase, you might even omit pH adjustment completely and thereby get the full effect of SA without an uncomfortable feeling due to a low pH (especially if you don’t add any solvents to the water phase which might draw SA out of the oil and into the water phase). Sure, pH might be really low but the amount of SA causing that will be small and easily be compensated by pH active substances on your skin = not as irritating as the same % of lactic acid (water soluble AHA) at a pH possibly even 0.5 to 1 unit higher.Alternatively, you could substiture BTMS with stearamidopropyl dimethylamine (I think this blend might be patent protected, check if you’re trying to sell your creation). It’s an alkaline cationic emulsifier somewhat similar to BTMS but will react with some of the SA to form a composit acting as cationic emulsifier and water soluble salicylate at the same time (with SA keeping some of it’s activity compared to neutralisation with TEA or NaOH). However, you might want to combin that with more cetyl alcohol and/or glyceryl stearate and probably also with an approximately equal amount of an emulsifier having two alkyl chains such as distearoylethyl dimonium chloride (Varisoft EQ65) and/or a polyglyceryl diester (thinking of Emulium mellifera).Per @Dtdang‘s suggestion: A nonionic emulsifier with a large head group (PEG-100 stearate, polyglucosides, polyxylosides…) would be a wise co-emulsifier in your case. In general, nonionics should also work as main emulsifiers (many but not all are salt tolerant) whilst an anionic one will require some knowledge of its chemistry (not all work at low pH, go with sulfate/sulfonate/taurate/isethionate) and make for a great fortifying co-emulsifier in a nonionic base.
Your wise words leave me speechless in gratefulness, with your comment, I can do a lot more researchs and ask less dummy questions. Thanks alot again.
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Dtdang said:Replace your bmts 125 with non-cationic emulsifier.
Thanks for suggestions
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