Formulation Questions: Tranexamic Acid in Sunscreen, Brightening Extracts, Multi-Benefit Cream, and Ingredient Usage Strategy

This conversation covers several questions related to cosmetic formulation and ingredients:

1. Tranexamic acid in sunscreen: Tranexamic acid can be included in a sunscreen formula, specifically mentioning compatibility with SPF Ultra Protect and Mattesilica.
2. Natural extracts for brightening: Regarding natural extracts for skin brightening and reducing dark spots, French Pink Bark Extract 95 is considered more suitable than Centella Asiatica Extract (Madecassoside), which is primarily known for anti-aging effects. However, both extracts can significantly darken the product's color.
3. Recommendations for various concerns: For a cream focusing on wrinkles, firming, clogged pores, brightening, dark spots, melasma, and freckles, suitable for all skin types, Active Resveratrol™ is suggested (though it might be synthetic). French Pink Bark and Alpha Arbutin (also synthetic) are also discussed in the context of brightening.
4. Using the same main ingredients in day/night creams: Using the same main ingredients in both day cream and sunscreen (or night cream) at the same concentration has potential benefits and drawbacks. For irritating ingredients, it can increase irritation. For beneficial ingredients, there might be a limit to how much the skin can utilize, so using more might not provide proportionally better results.
5. Splitting ingredient concentration: It is possible and often beneficial to split the total recommended concentration of an ingredient between day and night applications (e.g., half in the morning, half at night). Applying lower concentrations more frequently can be more effective than applying a high concentration once.