Proposed Formula Modification for Vitamin C Gel-Cream

Based on your goal to create a stable Vitamin C gel-cream for pump packaging, suitable for FDA registration, and excluding Hyaluronic Acid, your proposed formula is a good starting point. It contains potent antioxidants and skin-benefiting ingredients. However, there are a few critical points to address regarding stability and texture to achieve your desired outcome.

Key Considerations and Suggestions:

1. Vitamin C Stability (L-Ascorbic Acid): L-Ascorbic Acid (15%) requires a low pH (ideally 3.5-4.0) for stability. Your formula includes Triethanolamine (alkaline) and Panthenol ExtraLite (high pH), which will raise the pH. Adding 1% Triethanolamine as listed will likely make the formula too alkaline for L-Ascorbic Acid to remain stable, leading to oxidation.

   • Suggestion: After mixing the acidic components and thickeners/emulsifiers, carefully measure the pH. Add Triethanolamine slowly while mixing and monitoring the pH until it reaches the target range of 3.5-4.0. You will likely need less than 1% Triethanolamine.

2. Texture (Gel-Cream & Stability): You want a gel-cream texture suitable for a pump and noted that 1% Pro Polymer was unstable. Your proposed 2% Pro Polymer and 0.5% ClayThick will contribute to thickening.

   • A significant challenge for a stable gel-cream containing both water and oil-soluble components (like LipidSoft Lite, Tocopherol, CoQ10, Protec series in the oil phase) is emulsification. Your formula lacks a primary O/W emulsifier. While Phospholipid can assist, it may not be sufficient to prevent separation of the oil phase from the water/gel phase, especially over time and in a pump bottle.
   • Suggestion: Strongly consider adding a suitable O/W emulsifier that is compatible with low pH and electrolytes. This is crucial for creating a stable emulsion that results in a consistent gel-cream texture and prevents phase separation. You may need to adjust the levels of Pro Polymer and ClayThick once an emulsifier is included to achieve the desired viscosity.

3. FDA Registration: Ensuring the final pH is between 3.5-4.0 is essential for FDA compliance for leave-on products containing L-Ascorbic Acid. You also need an effective preservative system. While 1,2-Hexanediol helps, a primary preservative is typically required. The original base included Phenoxyethanol.

   • Suggestion: Include a complete and effective preservative system in your formula. If using Phenoxyethanol, ensure it is at an appropriate concentration (e.g., 0.5-1%) and listed. Verify all ingredient percentages against current Thai FDA regulations.

4. Ingredient Incorporation: Ferulic Acid and Phloretin are powders that require proper dispersion/dissolution. Ferulic Acid is soluble in ethanol or DMI, not water. Phloretin disperses.

   • Suggestion: Dissolve Ferulic Acid in the ethanol/DMI portion. Disperse Phloretin using high shear mixing, possibly in a small amount of the water phase or solvent blend before adding to the main batch.

5. Coenzyme Q10: This ingredient is sensitive to heat and light. Add it in the final step when the formula temperature is below 40°C. Opaque packaging is recommended.

Summary of Proposed Formula (with considerations):

• Purified Water (Balance to 100%)
• L-ascorbic acid (Standard) 15%
• Tocopherol 2%
• Ferulic Acid 1%
• DMI 3%
• 1,2-Hexanediol 3%
• Phospholipid 2%
• Phloretin 2%
• Ethyl Alcohol (99.9%) 4%
• Pro Polymer (Gel Maker) 2%
• LipidSoft™ Lite 5%
• Protec OX™ 0.05%
• Protec UV™ 0.05%
• ActiveProtec™ 1%
• Disodium EDTA 0.2%
• Phytic Acid 0.2%
• ClayThick™ 0.5%
• Protec SQ™ 3%
• Coenzyme Q10 0.5%
• Triethanolamine (Adjust pH to 3.5-4.0 - likely less than 1% needed)
• Panthenol ExtraLite™ 1%
• Recommended Addition: Suitable O/W Emulsifier (e.g., compatible with low pH/electrolytes) - percentage depends on chosen emulsifier.
• Recommended Addition: Preservative System (if not covered by 1,2-Hexanediol and other components) - e.g., Phenoxyethanol 0.5-1% or other suitable blend.

By carefully controlling the pH, ensuring proper emulsification, and including a robust preservative system, you can create a stable and effective gel-cream Vitamin C serum with the desired texture for pump packaging and suitable for FDA registration.