Formula Review and Suggestions

Thank you for sharing your preliminary serum formula. It includes several excellent active ingredients targeting various skin concerns like aging, acne, exfoliation, and hydration. However, combining all these ingredients into a single stable and effective formula with a comfortable skin feel presents several challenges, primarily related to ingredient compatibility, stability requirements, and potential for irritation.

Here is a review of the proposed formula and some suggestions:

Potential Challenges and Considerations

1. Stability and Storage Requirements: This is the most significant challenge. Several key ingredients have strict storage requirements:

   • Glass Moist™: Requires refrigeration (6-8°C) for storage and for the finished cosmetic.
   • Resveratrol LongMax™: Requires refrigeration (5-10°C) and protection from light and heat.
   • Pineapple Enzyme (Bromelain): Requires storage at low temperatures (6-15°C) for optimal longevity and should not be exposed to heat above 40°C during mixing.
   • Galactomyces Ferment Filtrate: Requires refrigeration (4-8°C).
   • Hydro-Urea® Liquid: Should not be stored long-term above 25°C.

   Combining these means the final product must be stored in a refrigerator to maintain the efficacy and stability of these sensitive ingredients. This might not be practical for a typical consumer serum.

2. pH Compatibility: The optimal pH ranges for the active ingredients vary:

   • ActiveRelease™ Salicylic Acid & Natural PHA (Gluconolactone): Work best at lower pH (around 3-4.5) for exfoliation, though PHA is less pH-dependent than AHA.
   • Pineapple Enzyme (Bromelain): Most stable at pH 5.0-8.0.
   • Resveratrol LongMax™: Most stable at pH 3-6.5.
   • Prebio-care: Works in pH 4-10.

   Finding a single pH that keeps all ingredients optimally effective and stable is difficult. A compromise pH (e.g., around 4.5-5) might be necessary, but this could reduce the efficacy of the exfoliants.

3. Potential for Irritation: The formula includes multiple exfoliants: ActiveRelease™ Salicylic Acid (at the maximum allowed concentration of 5%, equivalent to 2% active SA), Pineapple Enzyme (Bromelain), Natural PHA (Gluconolactone), and potentially Sodium Lactate at 3% (which can have mild exfoliating effects at >3%). This combination might be too aggressive for the skin, leading to irritation, redness, or sensitivity, especially in a leave-on serum.

4. Texture and Feel: The combination of 15% Glass Moist™ (a cream gel), 3% Baobab Oil, and potentially a high percentage of Galactomyces Ferment Filtrate (if used as the base up to 100%) might result in a texture that feels heavier or tackier than a typical comfortable serum, potentially contradicting the "comfortable skin feel" goal.

5. ActiveRelease™ Salicylic Acid Concentration: While 5% is within the usage rate for this specific product (providing 2% active SA), combining it with other exfoliants increases the risk of irritation.

6. Hydro-Urea® Stability: While you included Natural PHA (Gluconolactone) which helps stabilize Hydro-Urea®, the recommended ratio is approximately 1:6 (Gluconolactone:Hydro-Urea). Your formula has a 1:5 ratio (1% PHA to 5% Hydro-Urea), which is close and should help, but long-term stability, especially above 25°C, remains a concern without refrigeration.

Suggestions for Improvement

Given the complexity and potential issues, consider these options:

1. Simplify the Formula or Split into Multiple Products: It might be more effective and stable to create two separate products:

   • An exfoliating/acne treatment serum (e.g., with Salicylic Acid, PHA, Prebio-care, Sodium Lactate, Sodium PCA, EDTA). This could target a lower pH.
   • An anti-aging/hydrating serum (e.g., with Resveratrol LongMax™, Glass Moist™, Galactomyces Ferment Filtrate, Hydro-Urea®, Sodium Lactate, Sodium PCA, EDTA, Baobab Oil). This serum would likely require refrigeration.

2. Adjust Concentrations: If keeping it as one serum, consider reducing the concentration of ActiveRelease™ Salicylic Acid (e.g., to 2-3%) to minimize irritation, especially alongside other exfoliants. Re-evaluate the need for 15% Glass Moist™ if other strong humectants are present.

3. Optimize pH: Carefully select a target pH based on the most critical actives and test stability and efficacy. Be aware that a compromise pH will likely reduce the effectiveness of some ingredients.

4. Consider Alternative Ingredients: If refrigeration is not feasible, research alternative forms of Resveratrol, Salicylic Acid, or enzymes that offer better room-temperature stability.

5. Review Galactomyces Ferment Filtrate Usage: Using it as the primary base ingredient up to 100% is unusual and likely contributes significantly to cost and potential texture issues. It is typically used as an active at lower percentages within a standard serum base.

6. Thorough Testing: Regardless of the final formula, extensive stability testing (including accelerated aging and freeze-thaw cycles) and efficacy testing are crucial, especially given the sensitive nature of many ingredients.

Designing a formula with this many potent and sensitive actives requires careful balancing and consideration of their individual requirements. Focusing on fewer, compatible actives per product often leads to more stable, effective, and user-friendly formulations.