Custom Serum Formulation for Anti-Aging, Brightening, and Hydration

This formulation appears well-designed to address your goals of skin rejuvenation, wrinkle reduction, moisture increase, and brightening for combination skin with freckles.

The ingredients you've selected are suitable for these concerns:

• Galactomyces Ferment Filtrate, Repair Activator (Bifida Ferment Lysate), Acetyl Hexapeptide-8 (Argireline), and Matrixyl 3000 target skin rejuvenation and reduce the appearance of wrinkles.
• Niacinamide, Acetyl Glucosamine, and Activated Resorcinol work together for brightening the skin and reducing freckles/dark spots.
• Galactomyces Ferment Filtrate, MOIST24, and Allantoin provide hydration and soothing benefits.
• Niacinamide can also help balance oil production, which is beneficial for combination skin.

Regarding the texture, the inclusion of Satin Cream Maker at 1.5% is intended to create a serum consistency. Combined with the high percentage of liquid ingredients (Galactomyces Ferment Filtrate and water), this should result in a texture that is neither too thick nor too thin, aligning with your preference for a serum.

The ingredients listed are generally compatible for mixing. However, it's always a good practice to check the specific usage instructions and compatibility notes for each raw material you purchase, especially for ingredients used at high concentrations like Galactomyces Ferment Filtrate at 40%.

Overall, this looks like a promising formulation for your skin type and goals.