Formulation Adjustment and Stability Troubleshooting for Booster Lifting Serum

Formulation Adjustment and Troubleshooting Guide

To proceed with the production of your Booster Lifting and Regenerating Serum, we have evaluated your proposed changes and addressed the stability issues (browning and sediment) based on the ingredient properties and formulation best practices.

1. Ingredient Replacement and Additions

The discontinued ingredients can be replaced as follows, but please note the changes in functional positioning:

• Repair Activator™ Powder: Your proposed Black Sea Moss Extract (1%) is a marine-based moisturizing and skin-conditioning agent. It is not a direct functional equivalent to the original Bifida Ferment Lysate (probiotic repair). If you prefer to maintain the "repair" concept, we recommend Repair Activator™ BG (liquid form).
• Quick-Coll®: VoluLift™ (1.5%) focuses on skin volume and firming. While it is an excellent anti-aging active, it may not perfectly replicate the specific collagen-support mechanism of the original ingredient.
• Jeju Camellia: Tuberose Fragrance Oil (0.5%) serves only as a scent replacement. It does not provide the botanical benefits of Camellia. Note that 0.5% fragrance is relatively high for a high-active serum; we suggest trialing 0.2–0.3% first to minimize irritation risk.
• Spilanthol Expression Liposome: Adding this at 0.5% or 1.0% is technically feasible. You must reduce the Purified Water by the same amount to maintain the 100% total.

2. Troubleshooting Stability Issues

A. Addressing the Brown Color Change (Oxidation/Light Sensitivity)
The browning (yellow to brown) within 2–4 weeks is likely due to the degradation of light-sensitive or oxidative ingredients, particularly Retinal-EZ™, EUK-134, or the oil-phase antioxidants.

• Deletion Trials: To identify the exact cause, prepare small lab batches (100g) where you remove one suspect at a time (e.g., one batch without Retinal, one without EUK-134, one without fragrance). Compare these against a control batch after 4 weeks.
• Packaging: Retinal is highly sensitive. You must use opaque, airless packaging to protect the formula from light and oxygen.
• Processing: Use low-light conditions during manufacturing and avoid heating the formula. Add sensitive actives (Retinal, BEE-TOX™, PDRN, Peptides, Fragrance) during the cool-down phase (below 40°C).

B. Addressing Sediment (Solubility and Recrystallization)
The sediment is likely caused by the high load of powders (Niacinamide 8%, Tranexamic Acid 3%, GlucoBright™ 4%, Panthenol 0.5%, and Adenosine 0.5%) relative to the limited water phase (~25%).

• Solubility Check: Verify if the total powder load (approx. 16%) can remain fully dissolved in the available water. Pure-Adenosine™ at 0.5% is a primary suspect for recrystallization.
• Observation Period: Prepare the water phase with all dissolved powders first. Observe this solution for 24–48 hours at room temperature and in a refrigerator to check for recrystallization before proceeding with the full batch.
• Adjustment: If sediment persists, consider reducing Adenosine to 0.1–0.3% or increasing the water/solvent ratio.

3. Recommended Specifications and Testing

• Target pH: Aim for pH 5.8–6.2 as a starting point. This range is a compromise between the stability requirements of Retinal, BEE-TOX™, and PDRN (all typically stable up to pH 6.5).
• Stability Testing:
  • Temperature Cycling: Store samples at 4°C, 25°C, and 40°C.
  • Centrifuge Test: Check for physical separation.
  • Light Exposure: Compare samples in clear vs. opaque bottles under light.
• Microbial Testing: Perform a Microbial Limit Test (MLT) and Preservative Efficacy Test (PET/Challenge Test) due to the high nutrient content.
• Efficacy/Claim Support: Consider instrumental tests for hydration (Corneometer), wrinkle depth (Photo grading), and skin brightness (Colorimeter).

4. Production Process

1. R&D Reformulation: Submit the revised formula for a lab-scale trial (100–200g).
2. Stability Screening: Confirm the lab batch passes the 4-week stability and solubility checks.
3. Pilot Production: Once the lab batch is stable, proceed to a pilot production run.

Citations:

• ICH Q1A(R2), Stability Testing of New Drug Substances and Products, 2003.
• ISO 11930:2019, Cosmetics — Microbiology — Evaluation of the antimicrobial protection of a cosmetic product.
• Tadros, T. F., Emulsion Formation and Stability, Wiley-VCH, 2013.
• McClements, D. J., Food Emulsions: Principles, Practices, and Techniques, 3rd ed., CRC Press, 2015.