Formulation Review

Regarding the two formulations you provided and your concern about the proportions, the staff previously confirmed that these combinations are mixable according to specific instructions.

However, determining if the proportions are "correct" depends on the desired efficacy and the recommended usage rates of each ingredient, as well as regulatory limits.

Here's a review based on the product information:

Formula 1

• Perfect-C™ (Ascorbyl Tetraisopalmitate) 10%: The recommended usage rate for Perfect-C™ is 1-10%, with 5% recommended for efficiency. Your 10% is within the recommended range.
• Repair Activator™ 10%: The recommended usage rate for Repair Activator™ is 5-100%. Your 10% is within the recommended range.
• Transderm A 64%, Transderm B 16%: These components form the base. Without specific product information for "Transderm A" and "Transderm B", I cannot comment on whether these percentages are the most appropriate for creating a stable and effective base for the active ingredients.

Formula 2

• Perfect-C™ (Ascorbyl Tetraisopalmitate) 5%: Your 5% is within the recommended range (1-10%) and matches the recommended percentage for efficiency.
• Repair Activator™ 10%: Your 10% is within the recommended range (5-100%).
• Ethoxydiglycol 5%: The product description for Ethoxydiglycol states a recommended usage rate of 1-10%. However, it also notes current FDA conditions limiting use to not more than 2.6% for leave-on or skin spray products. Since this is likely a leave-on product, your proposed 5% exceeds this regulatory limit. You should reduce the concentration of Ethoxydiglycol to 2.6% or less.
• Transderm A 64%, Transderm B 16%: Similar to Formula 1, I cannot comment on the appropriateness of these base percentages without specific product information.

Mixing Instructions (as provided by staff)

• Formula 1: Mix Perfect-C™ in the oil part of Transderm. Mix Repair Activator™ in the water part of Transderm.
• Formula 2: Mix Perfect-C™ in the oil part of Transderm. Mix Repair Activator™ and Ethoxydiglycol in the water part of Transderm.
• Important: Chill the water part of Transderm before mixing while it is cold.

In summary, while the ingredients are mixable, the percentage of Ethoxydiglycol in Formula 2 exceeds the recommended maximum for leave-on products. You should adjust this percentage accordingly. The percentages for Perfect-C™ and Repair Activator™ are within their general recommended ranges. The suitability of the Transderm A and B percentages depends on their specific properties.