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pH
Good day great minds.
I’m still a learner in this field of life.
In my formulation I’m using the following:Niacinamide. - pH of 3.5 - 7.5
N-acetyl Glucosamine. - 5-6
Since N-ACETYL works well with Niacinamide.
Giga White - 3.0-6.5
Licorice 5-9My concern now is that, I want to add Sodium Ascorbyl Phosphate (SAP) which its pH is fixed or more stable at 6. What do you advice I do, since I’m aiming my final product pH to be 5.5? Should I removed it or what can I do for it to still be there?
Prior to this time, I was taught that Niacinamide pH is 6, but most formulators are putting the above pH on their site, please how true is this?
I’m adding licorice to also help fight against free radicals.
In anticipation for your reply.
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11 Replies
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There is a paper called “Rate Studies on the Hydrolysis of Niacinamide” and they used hydrochloric acid to perform the experiment in the acid region. The study found that a 10% Niacinamide solution heated to around 89 degrees C and then taken to a pH of below 4.5 with a STRONG acid did start to hydrolyse and form Niacin and that this conversion was a first order reaction which it says basically means it went from Niacinamide to Niacin without turning into anything else first. The study found that between pH 4.5-6 very little of this shifting occurred and in fact at pH 4.5 – 6 the half-life of the solution was found to be 1000 days which probably means that the average cosmetic formulator has little to worry about. So would be good if this is true.
I have formulated with Niacinamide at around pH 5 with no issues and also now add in my cool-down stage when doing emulsions as other info I have found out from a Cosmetic Chemist here in Australia said it should be added at temps below 70 degrees C. It would be good to hear what other real Chemist have to say
Just type Niacinamide in the Search area and see what other discussions there are on this forum. CheersAlso this link
Using Niacinamide in an acidic formulation | Realize Beauty (wordpress.com) -
If you want to add the SAP, then the pH of your formula should meet it’s stability requirements unless you are only adding it for marketing / filler purposes. There’s nothing wrong with having the pH at pH 6. If you are concerned about your user’s idea that moisturizers should be pH 5.5 or “pH balanced”, you can always disclaim that assigned pH is for the stability is for the SAP.
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Okay. Thanks alot for your comments. Please, how do I effectively dissolve the Niacinamide to be added at below 70 degree C.
Also, please, which other ingredient can I use to replace the SAP to have exact pH of around 5?
From the comments above, the only issue now is the SAP.
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There’s normally no issues with dissolving Niacinamide in water.
You can use other Vit C derivatives that is within that pH range.
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Okay. Thanks. Should I use cold or hot water in dissolving it? I’m using 5% of it.
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Please, I went to search more on alternative to SAP, as for MAP, some site said pH 6, below 6 will cause discloration. Some said 7-8 to be more stable. Some said 5-6, anything less or higher won’t be stable. Please, I need assistance, which is true?
I would have used L ascorbic acid, but, I’m scared of oxidation.
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Ethyl Ascorbic Acid or Tetrahexyldecyl Ascorbate or Ascorbyl Tetraisopalmitate
You can just use normal temperate water for Niacinamide. If you want to use hot water, then just below 70 degree C that you have mentioned if it’s based on supplier recommendations.
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Wow! Thanks alot
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I’m sorry for the constant question, I really want to get it right, can I use any of the above alternative you mentioned with Niacinamide?
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If it’s within the pH range, yes.
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Okay. Thanks a great deal
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