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Geogard Ultra
I’ve recently try Geogard Ultra in one formula and really liked it because it has hardly any scent, so it doesn’t compete with fragrances.
My question is: it is advised to use a buffer in your formula because Geogard Ultra drops the pH quite considerably. At Lonza website, they recommend to use sodium citrate with it, 1.5x of the amount of the preservative. My question is: can I substitute for sodium lactate, or it would with time destabilise the formula?
Thanks in advance
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5 Replies
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It is a really poor preservastive at any concentration and pH.
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I’m not sure I understand your question. Why do you want to use a buffer system in your formula? For Geogard Ultra Gluconolactone (and) Sodium Benzoate) to work you just need to adjust the pH below pH 5.0. No buffering required. But as @PhilGeis said, it’s not a very robust preservative system.
Sodium Citrate has 3 acid groups on it while sodium lactate has 1 so there will be differences.
Finally, it’s pretty rare that anyone could predict stability of a system without making it and testing it. Unless there is some obvious ingredient conflicts, the only way to know is to make the system and test it.
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Thanks @PhilGeis for your reply, I’m not going to lie, I got a bit upset that s not a very good preservative since I’ve being loving it! But is good to know that it might not be the one I will stick to
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Thanks @Perry for you reply. The reason I mention the buffer is only because Lonza recommends it. I got their PDF about the preservative and that is what is recommended.
I did test both of them and the final pH of the cream changed significantly, so thanks on the info about the acid groups!
I am just back to formulating, and I still have tons to learn, so I’m very grateful to be accepted here! Thanks for sharing all your knolodge Perry!
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Here the instructions on how to use it. It tends to low the pH of the formulation slowly with the time, then the supplier recommends to neutralise it to pH 7.5 first, then add the other ingredients and adjust the pH of your formulation to 5-5.5 with citric acid. I am using it now and will let you know how it goes
Hope this help.
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