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Help figuring out percentages
This is my formula for one of my serums. I am trying to figure out the cost per gallon but I have no idea what % each ingredient is (minus mandelic and lactic) because a lab makes it for me. Can anyone give me a sample of % based on a your experience of what each one would relatively be in a formula. I am just trying to get a ballpark figure. Thanks!
Purified Water,8% Mandelic Acid,3% Lactic Acid,Sodium Hyaluronate,NiacinamideSodium PCASodium LactateGlycerinHamamelis Virginiana Leaf ExtractGlycyrrhiza Glabra Root ExtractCamellia Sinensis Leaf ExtractXanthan Gum -
7 Replies
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Niacinamide will degrade at the pH that is required for AHAs to be active. And yes I know some commercial brands that do it, but they are wasting materials.
You can add as little of extracts as you want. They don’t provide any tangible benefits and are added for claims. As long as you have one drop there, you can say it on the label (0.001%?).
Humectants: 5% altogether, and you don’t need all 3.
Sodium Hyaluronate - is it a gel maker or a claim ingredient in this formula?
If it’s a gel maker, 0.50-1% and you don’t need xanthan. If it’s a claim ingredient see extracts.
Xantan.. 0.3-0.5% you need to experiment and see what you like. -
The first thing you should do is to take a sample, determine the mass (weigh it), then put it in an oven for a couple hours. After that, you weigh it again. Put it back in the oven for another half hour and then weigh the sample again. If the weights haven’t changed, congratulations…you now know the approximate % of water in the formula.
The rest of the numbers will have to add up to 100% - % water. After that, you’ll just have to guess but most likely Glycerin is the highest percentage ingredient and the others are lower.
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awesome, thank you! I just read that about niacinamide not working in acids.
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@ngarayeva001
Thank you for the help. Based on that ingredient deck do you see a preservative in there? I don’t, but maybe I am missing something. Do I need one in this type of formula? -
I don’t see any preservatives here. There could be two reasons: it’s either a very poorly formulated product (and niacinamide+acid gives me a hint that it might be the case) or the pH is very low (below 3) and they relied on it. Again not a great idea, because it can drift, plus you don’t want to keep it lower than needed as many users would have irritation. My skin tolerates anything above 2.5 but I wouldn’t advise doing it. I don’t see TEA or NaOH in this LOI. Another warning sign. Is it a commercial product?
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It’s a formula that was made for me from a lab. I don’t make it myself but I am hoping to and if it’s not stable as is because of the niacinamide or lack of preservative then I probably should just make it. Do you think sodium benzoate would be an appropriate preservative? Mandelic is pretty stinky. Is there a preservative that masks product smell? @ngarayeva001
I appreciate the feedback! -
In general sodium benzoate alone is not sufficient. It’s usually used in combination with other preservatives. Preservatives are not designed to mask the smell of the product. Moreover, preservatives often don’t smell nice themselves. Although some people like the smell of Phenoxyethanol and think it smells like flowers. To me, it smells like a chemical weapon.
I heard of one exception, a preservative that is called naticide which is also used as a fragrance. It’s not a broadspectrum preservative, and you need to check at what pH it’s active.
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