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W/O emulsion preservation
Hello ,
I am working with a W/O emulsion at pH7 to 7.1 and trying to determine the best way to preserve it .
I am using PEA at 0.8 , glycol (propanediol and pentylene glycol at around 2.2% water phase) and Magnolia bark extract in the lipid phase .
My question is, is w/o considered easier to preserve than o/w ? Any tips on how to improve the preservation at 7 to 7.1pH ? (I cannot use Glyceryl caprilate at 7.1…or can I ? Some companies claim that it works until pH 7.5). I am even thinking to use zinc lactates..
Thx you for your time.
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16 Replies
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Magnolia bark - do not use.
One does not preserve the lipid phase - we preserve the water phase and the lipid-water interface.
Water in oil is a different micro risk. Generally, the bugs offered in use can’t find the water droplets to grow. Since preservatives are in the water phase, the same dynamic will male it difficult to pass an challenge test.
86 (with prejudice) the magnolia bark and add something for fungi. Do you have a chelator? Why must pH be ~7 rather than lower?
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We need to keep ph 7 because ultramarine blue pigment is acid sensitive. I am aware that we don’t preserve lipid phase but I have used glycol to lower the interface tension and hoped that magnolia bark can help preserve the water phase. So what else can I do, increase the glycol maybe? I cannot use chelator since w/o is stabilized by using magnesium sulfate… How about zinc lactate, will it help?
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Propylene glycol is fully miscible in water and not in the oil phase. Also, the reduction on interacial tension of the water phase is marginal. That’s achieved by surfactants which have a hybrid structure able to interact with both phases, so I wouldn’t worry much about glycols on that regard.
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what is your process and package?
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You can use some phenoxy ethanol or phenethyl alcohol
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Cold process , package is air tight (pump)
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how good are you raws - esp. water?
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All tested, water is tested and double distilled.
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Micro risk here is making and packing - formula, process design and raw material control. Cold process does not help. “Tested” by you or supplier. Water - to what level of detection.
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Raw materials are tested by the supplier with a COA. Water is made in EU and tested also by supplier.
My questions are :
1. Do I have to worry in W/O emulsion about the interface of 2 phases like in O/W ?
2. Will Zinc lactate help at around 0.5% to make the preservation more robust ?
3. I understood that in W/O I have to only worry about W (I guess its the first point again)..is that correct ?
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no - you can worry but can do nothing about it
no
yes
So you’ve no micro capability?
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Yes I do ,we just acquired Biolumix that should be installed next week.
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why Biolumix?
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The company is very reactive , they also did the test that shows equivalency with the ISO testing. So now we can do micro in house.
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Not sure what reactive means. Neogen/Biolumix level of detection is greater than what most folks use.
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Very reactive means they answered my questions , replied to my emails and addressed any concern we had. They reacted.. ( I think its a french term)
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