Mixing Vitamin C Ester and Vitamin B3 in Lotion: Color Change and Effectiveness

Based on the provided information:

1. Color Change: The staff explained that Vitamin C Ester powder is naturally yellow, which causes the cream to turn a light yellow color when mixed. This is normal for this ingredient.
2. Mixing Vitamin C Ester and Vitamin B3 (Niacinamide): The cosmeceutical staff advised that while Vitamin C Ester is a derivative, mixing it directly with Vitamin B3 in the same formula is not recommended. This is because Vitamin C (especially L-Ascorbic Acid) and Vitamin B3 can interact, potentially reducing their effectiveness. Although Vitamin C Ester is less reactive before skin absorption, the recommendation is to apply them separately to ensure maximum efficacy and avoid potential issues after skin absorption. Therefore, the color change might also be related to this interaction, indicating reduced effectiveness.
3. Recommendation for Use: To achieve the best results and avoid potential interaction and reduced efficacy, it is recommended to apply Vitamin C Ester and Vitamin B3 separately, rather than mixing them into the same cream.
4. Mixing Ratio: The staff recommended mixing Vitamin C Ester at 5% and Vitamin B3 at 5% into 100ml of lotion. (This implies adding 5g of Vitamin C Ester powder and 5g of Vitamin B3 powder to 100g/ml of lotion, approximately).
5. pH: The provided information does not specify the ideal pH for a mixture containing all these ingredients. The recommendation to apply separately bypasses the need to find a single pH suitable for both ingredients in the same formula.
6. Glycerin and Adding More B3: The provided information does not cover the appropriate ratio for Glycerin or the process of adding more Vitamin B3 to a lotion that already contains it.

Summary: The yellow color is expected from Vitamin C Ester. However, mixing Vitamin C Ester and Vitamin B3 together is not recommended due to potential loss of effectiveness. It is best to apply them separately. The recommended mixing ratio (if mixing) is 5% of each in 100ml of lotion. Other questions were not addressed in the provided text.