Using Magnesium Ascorbyl Phosphate (MAP) or Sodium Ascorbyl Phosphate (SAP) with Water

Yes, both Magnesium Ascorbyl Phosphate (MAP) and Sodium Ascorbyl Phosphate (SAP) are water-soluble and can be mixed with plain water.

• Storage: For long-term storage, it is recommended to store the mixture in the refrigerator, away from sunlight and humidity, with the lid tightly sealed. These forms of Vitamin C are highly stable, especially when stored properly.
• Mixing Amount and Shelf Life: You can mix the amount you need for a period, and it can be stored for a long time under good storage conditions (refrigerated, away from light and humidity). The stability in water is good, unlike L-ascorbic acid.
• Usage Rate: The recommended usage rate for both MAP and SAP is 0.5-10%, with 3% being a common recommendation. Using concentrations above 8% might lead to dissolution issues.

Keep in mind that for optimal stability of MAP and SAP in a formula, the pH should be in the range of 7-9. While mixing with plain water is possible, formulating a complete product might require pH adjustment and potentially adding a chelating agent like Disodium EDTA (0.05%) to handle metal ions that could affect stability.