Usage Percentage and pH Adjustment for MAP/SAP in Whitening Formulas
Question
I am developing a whitening formula and plan to use Magnesium Ascorbyl Phosphate (MAP) or Sodium Ascorbyl Phosphate (SAP). I would like to know the recommended maximum usage percentage for MAP/SAP, specifically if using 10% or 15% is acceptable.
Additionally, I understand that MAP is alkaline. What is the recommended pH range for a formula containing MAP/SAP, and what ingredient can be used to adjust the pH down to the appropriate level?
My formula also includes:
- B3
- N acetyl glucosamine
- Alpha arbutin
- Double HA
Are these ingredients compatible with MAP/SAP, especially regarding the pH adjustment?
Answer
Regarding your question about using Magnesium Ascorbyl Phosphate (MAP) in your formula at 10% or 15%:
Based on general recommendations and the information provided (from cosmeceutical7), the typical recommended concentration for MAP/SAP in cosmetic formulations is not exceeding 10%.
Using concentrations higher than 10% is often considered risky and may not provide significantly increased benefits, while potentially leading to stability issues or skin irritation. Therefore, 10% is at the higher end of the recommended range, and 15% is generally not advised.
It is also crucial to pay attention to the pH of your final formulation when using MAP. As mentioned by cosmeceutical7, MAP is quite alkaline. You should adjust the pH of your formula down to approximately 6-6.5 using an acid like lactic acid. This pH range is important for the stability and efficacy of MAP.
The other ingredients in your list (B3, N acetyl glucosamine, alpha arbutin, Double HA) are generally compatible with each other and with MAP, provided the pH is correctly adjusted.
In summary, it is recommended to use MAP at 10% or less and ensure the final formula pH is adjusted to 6-6.5.