Modifying Serum Formula: Adding Extracts and Changing Preservatives

Regarding the Care & White Serum (or Good Will Advanced Anti-Aging Whitening Serum) formula you asked about:

Modifying or adding extracts to a cosmetic formula is possible, but there are several important considerations to ensure the new formula remains stable, safe, and effective.

Adding More Extracts:

• Compatibility: New extracts must be compatible with other ingredients in the formula (e.g., soluble in water or oil phase, not precipitate, or cause undesirable reactions).
• Stability: Adding certain extracts can affect the overall stability of the formula, such as changing the pH, altering the texture, or causing other ingredients to degrade faster.
• Optimal Concentration: Each extract has a recommended concentration range. Using too much may not increase efficacy but could cause irritation or make the formula unstable.
• Impact on Preservation System: Some extracts can be a food source for microorganisms or interfere with the effectiveness of the existing preservative. Adding extracts may require adjusting the type or concentration of the preservative as well.

Changing the Preservative:

• Effective pH Range: Each preservative works best within a specific pH range. You must choose a preservative suitable for the formula's pH.
• Efficacy Spectrum: Different preservatives have varying abilities to inhibit bacteria, fungi, and yeast. You must choose a type that covers the microorganisms likely to contaminate the formula.
• Compatibility with Other Ingredients: The preservative must be compatible with other ingredients in the formula and not react with or reduce the effectiveness of other components.
• Usage Concentration: It must be used at the recommended concentration to be sufficiently effective and safe.

Recommendation:
When modifying a formula, whether by adding extracts or changing the preservative, stability testing should be performed to see if the formula remains stable over time under various conditions, and challenge testing should be performed to ensure the new preservation system effectively prevents microbial growth throughout the product's shelf life.

If you have specific extracts or preservatives in mind, please let me know their names, and I can provide basic information about their properties and usage.