Formula Modification and Color Stability Issues in Lifting & Regenerating Serum

Question

I would like to modify my serum formula because some ingredients are no longer available. I want to make the following changes:

Use Black Sea Moss Extract (Hydrolyzed Rhodophyceae extract) 1% to replace Repair Activator™ Powder (Bifida Ferment Lysate)
Use VoluLift™ (Palmitoyl Isoleucine) 1.5% to replace Quick-Coll®
Use Tuberose Fragrance Oil 0.5% to replace Jeju Camellia (compare to Organist)
Add Spilanthol Expression Liposome (Natural Botox, Spilanthol 1.5% Water Soluble) 0.5% or 1% and reduce the water content to balance the formula to 100%.

Also, I need advice regarding the product's color changing from light yellow to brown after being left at room temperature for about 1 month. Do I need to add any specific ingredients to prevent this?

Current Formula: Booster Lifting and Regenerating Serum

Salmon DNA (PDRN, Polydeoxyribonucleotide, 5000ppm Solution) 12.00%
Super-HYA™ (Sodium Acetylated Hyaluronate, AcHA) 0.10%
8D Hyaluronic Acid 10.00%
BEE-TOX™ (100ppm Melittin Bee Venom Solution) 8.00%
Repair Activator™ Powder (Bifida Ferment Lysate) 1.00%
Pro-Xylane (Hydroxypropyl Tetrahydropyrantriol, Liquid) 2.00%
Ethylbisiminomethylguaiacol Manganese Chloride 0.05%
Retinal-EZ™ (Encapsulated Water Dispersible Retinal) 5.00%
Pure-Adenosine™ 0.50%
Quick-Coll® 2.00%
Pep-Calm™ (Palmitoyl Tripeptide-8) 2.50%
Tranexamic Acid (Trans-White™) 3.00%
Safe-B3™ (Vitamin B3, Niacinamide, Switzerland) 8.00%
GlucoBright™ (Acetyl Glucosamine) 4.00%
Tocotrienols (Oil, 50%, Cosmetics) 1.00%
Panthenol (Vitamin B5, DL-Panthenol, Powder) 0.50%
Kukui Nut Oil 2.00%
Shea Butter (Melt) 2.00%
ActiveProtec™ OX 1.00%
LipidSoft™ Moist (Triethylhexanoin) 2.00%
Dimethyl Isosorbide (DMI) 3.00%
LecithinGel™ 2.50%
Jeju Camellia (compare to Organist) 0.50%
Mild Preserved Eco™ (Preservative-Free) 1.00%
Purified Water (TDS Limit 1ppm) 25.35%
Methylsilanol Mannuronate 1.00%
Total = 100%

Answer 1

To update your Booster Lifting and Regenerating Serum formula and address the color stability issue, here are the recommended adjustments:

1. Formula Substitutions and Additions

The ingredients you requested can be integrated into the formula as follows:

Black Sea Moss Extract (1%): Replaces the previous lysate powder. It is water-soluble and can be added directly to the water phase.
VoluLift™ (1.5%): Replaces the previous collagen booster.
- Note: This ingredient is a powder that must be dispersed in the oil phase (such as your carrier oils or emollients) before emulsification. Avoid high heat.
Tuberose Fragrance Oil (0.5%): Replaces the previous floral fragrance.
Spilanthol Expression Liposome (1%): Added as a new active. Since it is water-soluble, it can be added to the water phase or during the final stage.

2. Adjusted Water Ratio

To accommodate the addition of 1% Spilanthol and the change in the collagen booster percentage, the water content should be adjusted:

Purified Water: 24.85% (decreased from 25.35% to keep the total at 100%).

3. Addressing the Color Change (Yellow to Brown)

The change from light yellow to brown within a month indicates oxidation or instability of sensitive actives, specifically the Retinal and the antioxidant manganese complex in your formula.

Recommendations for Stability:

pH Control (Critical): The antioxidant manganese complex (EUK-134) is highly sensitive to pH. It must be kept within a pH range of 6.0–8.0. If the pH drops below 6.0, the ingredient will degrade, leading to color changes and loss of efficacy. Please check and adjust the final pH to approximately 6.5–7.0.
Oxidation Protection: Retinal is extremely sensitive to light and oxygen.
- Packaging: You must use Airless Pump packaging that is completely opaque (blocks 100% of light).
- UV Stabilizer: Consider adding a UV stabilizer (at 0.1-0.2%) to the formula to protect the Retinal from light-induced degradation.
Antioxidant Support: While your formula already contains an antioxidant system, ensure it is fully dissolved. The brown color is a sign that the Retinal is oxidizing; keeping the product away from air is the most effective solution.