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Preservative on a base cream
I have a very basic question. I have a formulation of a base cream which is:
Stearic acid 12%
TEA 1%
Glycerin 5%
Gliceryl monostearate 4%
Propylene glycol 3%
Now, I want to add DMDM hydantoin and added with biosurfactant as a potential preservative. I want the DMDM Hydantoin to be 1500 ppm (1.5%) and the biosurfactant to be 350 ppm (0.35%). I have a stock solution of 55% DMDM Hydantoin and 5000 ppm biosurfactant. How much should I add the preservative into the base cream to have the desired concentration to be exactly what I wanted?
I’m a high school student working on a project but no one seems to understand..
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4 Replies
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What is your pH?
Do you also use some EDTA?
1500ppm is 0.15% so 0.28% dmdm hydantoin will give you almost that mach.
You will need an anti fungal too.
What is bio surfactant?
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no i dont use EDTA.
Can you give me calculation on how you get 0.28% of dmdm hydantoin?
Biosurfactant is surfactant that is produced by microbes. It’s reported to have antifungal effect so I’m trying to combine DMDM hydantoin and biosurfactant to get broader spectrum of antimicrobial
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0.28*0.55=0.1540 ppm
If it is produced by microbes then it doesn’t kill them. Use something that kill microbes.
And use some EDTA too.
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the formula you need is: concentration1 X volume1 = concentration2 X volume2
Concentration1 - is the % in the raw material DMDM hydantoin 55%
Concentration2 - the target concentration in your product - 1500 ppm - 0.15% (think 2000 ppm would be better)
Volume1 - is the amount of raw material 55% DMDM hydantoin to be added to your product
Volume2 - is the total volume of your product
For 100 ml of product - you’d add ~0.27 ml.
Please tell us the biosurfactant. That “preservative” capacity is highly doubtful - more likely (marketing) BS.
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