Formula Review and Shelf Life for Anti-Wrinkle Serum

Thank you for providing your anti-wrinkle serum formula for review. It contains a good selection of ingredients targeting hydration, anti-aging, and brightening.

Here is an evaluation of the formula and recommendations for adjustment:

Formula Evaluation and Recommendations

1. Glabridin 40% Dissolution: Glabridin 40% is not soluble in water or oil directly. It requires dissolution in a solvent like Butylene Glycol or Ethanol at a concentration of at least 10 times the amount of Glabridin. Your current formula does not include these solvents. To effectively incorporate Glabridin, you need to add a suitable solvent (e.g., 1% Butylene Glycol or Ethanol for 0.1% Glabridin) and dissolve the Glabridin in it with gentle heating (50-60°C) before adding this solution to your main formula in the final step.

2. Preservation System: Mild Preserve Eco at 1% is at the lower end of the recommended usage rate (1.0-1.5%) for general cosmetics. Given the presence of multiple natural extracts and proteins, which can be prone to microbial growth, it is highly recommended to either increase the concentration of Mild Preserve Eco to 1.5% or conduct a microbial challenge test on your final formula to ensure adequate preservation. Note that Aloe Vera Extract and Double Hyaluron Liquid also contain Phenoxyethanol, which contributes to preservation, but testing is the best way to confirm efficacy.

3. pH Level: Many of your active ingredients, such as Argireline, Alpha Arbutin, Japanese Cedar, Madecassoside, Collagen HP, and Witch Hazel, have specific pH requirements for optimal stability and efficacy, generally ranging between 3.5 and 6.5. After mixing all ingredients, you should check and adjust the final pH of your serum to be within this range (ideally 4.0-6.5) to ensure the ingredients perform as expected and remain stable.

4. Mixing Method: Pay close attention to the mixing instructions for individual ingredients. Heat-sensitive ingredients like Argireline, Pep-Coll, Madecassoside, Witch Hazel, Alpha Arbutin, Snow Algae, Collagen HP, and Blue Vitamin E Beads should be added in the final cooling phase (below 30-40°C, or below 60°C for Snow Algae) with minimal agitation, especially after adding the Blue Vitamin E Beads to prevent them from breaking.

5. Ingredient Concentrations: The concentrations of most active ingredients are within the recommended ranges. For enhanced effects, you might consider increasing Vitamin B3 to 5% or Alpha Arbutin to 2%, which are common effective concentrations, provided the formula remains stable and non-irritating.

Shelf Life

The shelf life of your serum depends on several factors, including the effectiveness of the preservative system, the stability of the ingredients over time, the packaging, and how the product is stored. With a properly preserved formula (confirmed by microbial challenge testing) and stored under appropriate conditions (such as in a cool place or refrigerator, which is recommended for several ingredients like Allantoin, Raffinose, Alpha Arbutin, Snow Algae, Japanese Cedar, Argireline, Pep-Coll, and Blue Vitamin E Beads), the serum could potentially have a shelf life of 1-2 years.

However, it is crucial to perform stability testing and microbial challenge testing on your specific finished product to determine its actual shelf life and ensure its safety and quality over time. Without these tests, any estimate is approximate.

By addressing the Glabridin dissolution, confirming adequate preservation, adjusting the pH, and following proper mixing procedures, you can improve the stability and efficacy of your anti-wrinkle serum.