Combining Alpha Arbutin and Perfect-C for Brightening and Melasma, and EDTA Use

Yes, Alpha Arbutin and Perfect-C (Ascorbyl Tetraisopalmitate) can be used together in a formulation aimed at skin brightening and treating melasma. Both ingredients are known for their skin-lightening properties, working through different mechanisms, which can offer a synergistic effect.

• Alpha Arbutin is water-soluble and works by inhibiting the enzyme tyrosinase, reducing melanin production. It is stable in formulations with a pH between 3.5 and 6.5.
• Perfect-C is oil-soluble and is a stable form of Vitamin C that brightens skin, provides antioxidant benefits, and helps stimulate collagen. It is recommended for use in formulations with a pH within 6.0, ideally between 5.0 and 5.5.

To combine them effectively, you would typically create an emulsion (like a cream or lotion) or a biphasic serum that can incorporate both water-soluble and oil-soluble components. The final pH of the formulation should be adjusted to the range that is suitable for both ingredients, such as pH 5.0-5.5, which falls within the optimal range for both Alpha Arbutin and Perfect-C.

Regarding Disodium EDTA, the description for Perfect-C explicitly recommends including Disodium EDTA at 0.2% in the formulation if water is present. This is to help capture metal ions that could potentially degrade the Vitamin C derivative, even when using purified water. While purified water (like the one with TDS limit 1PPM) has very low ion content, adding Disodium EDTA provides an extra layer of stability for the Perfect-C, ensuring its efficacy over time. Therefore, it is recommended to include Disodium EDTA in your formula even if you are using purified water.

For a formula focusing on brightening and melasma, you could consider using Alpha Arbutin at its recommended effective rate (e.g., 2%) and Perfect-C at its recommended rate (e.g., 5-10%). Remember to formulate within the appropriate pH range (5.0-5.5) and include Disodium EDTA (0.2%) in the water phase for stability.