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Hair color developer/ hair color oxidant
Hi
I am formulating a hair color developer 6℅ with hydrogen peroxide 50℅. I have some questions about it and would be happy if so. guides me:
1- how to make a buffer system with H3PO4 to keep pH between 2-3. (All info on the net is about how to make a buffer in water with no other ingredients). And is it important to use buffering agents in this system?
2- How to measure the stability of the H2O2 in the developer cream. Is not it dangerous to put in it an oven in 45’c for 2 months?
3-How to determine the shelf life of the product?
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2 Replies
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Critical to maintain an acidic pH but not THAT acidic, pH 4.0 - 5.0 sounds more like it. Use a phosphate or citrate buffer system since those also chelate metal ions, the enemy of peroxides. Do not accelerate aging at 45C. The old way was to reflux the solution for an hour then re-assay and report.
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@chemicalmet thank you for your attention my question.
Firstly you may say, the pH of a hair developer must be between 4-5, am I right? Then you mentioned I use a pre-prepared/purchase a buffering system of, let’s say, phosphoric accid/phosphoric acid sodium and disodium salts, which have been prepared and adjusted pH 4-5 in advance? So the only thing I should do is adjust the pH of the product with this buffer and maintain it 4-5?
Secondly, with refrence to determination of shelf life, I read the patent below in whitch it explained that for determining whether the product is stable for one year I have to heat the weighed finished hair developer at 95’C for 24h and then measure the amount of h2o2 via titration, is it correct?
https://patents.google.com/patent/US8357356B2/en
patents.google.com
US8357356B2 - Stabilized hydrogen peroxide compositions and methods - Google Patents
A hydrogen peroxide-containing composition comprising at least one antioxidant and at least one free radical scavenger operable to neutralize reactive oxygen species generated by the hydrogen peroxide and a method for stabilizing hydrogen peroxide containing compositions.
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