Understanding Ascorbyl Palmitate Solubility and Formulation

Regarding your questions about Ascorbyl Palmitate, its solubility, usage percentage, and how to incorporate it into a formula with water-soluble ingredients:

• Solubility and Usage: Ascorbyl Palmitate is indeed more soluble in Ethyl Alcohol (approximately 12.5%) than in natural oils (typically 0.03-0.12%). The recommended maximum usage rate for Ascorbyl Palmitate in formulations is up to 8%.

• Mixing with Water-Soluble Ingredients: Formulating a product that contains both oil-soluble ingredients like Ascorbyl Palmitate and water-soluble ingredients such as L-Ascorbic Acid, Sodium PCA, and Inositol presents a formulation challenge. Oil-soluble ingredients are typically incorporated into the oil phase of a formula, often requiring heating, while water-soluble ingredients are dissolved in the water phase.

• Ethyl Alcohol as a Solvent: Ethyl Alcohol can act as a solvent for Ascorbyl Palmitate, and it is miscible with water, meaning it can blend with water-based solutions. However, as noted, dissolving a high concentration of Ascorbyl Palmitate (like 8%) may require a significant amount of Ethyl Alcohol.

• Ethyl Alcohol and Skin: Using a high percentage of Ethyl Alcohol in a skincare formula can potentially lead to skin dryness and irritation. The amount of Ethyl Alcohol needed to fully dissolve 8% Ascorbyl Palmitate might be too high for a skin-friendly product, which aligns with the feedback you received.

• Formulation Approach: A common way to combine oil-soluble and water-soluble components is by creating an emulsion (like a cream or lotion) where the oil-soluble ingredients are dissolved in the oil phase and the water-soluble ingredients are dissolved in the water phase, and then these phases are combined using emulsifiers.

In summary, while Ascorbyl Palmitate is more soluble in Ethyl Alcohol than oil, using a high percentage of alcohol to dissolve it for a formula containing water-soluble ingredients might result in an undesirable concentration of alcohol for the skin. Formulating as an emulsion is a more typical method for combining such diverse ingredients.