Review of Serum Formula for Sensitive, Acne-Prone Skin

Subject: Review of Serum Formula for Sensitive, Acne-Prone Skin

Thank you for sharing your serum formula aimed at hydration, reducing inflammation, and addressing acne for sensitive skin. Let's review the ingredients and address your questions.

Ingredient Review:

• Aloe Vera Extract (8%): Excellent choice for soothing, hydrating, and anti-inflammatory benefits. Good concentration.
• Centella Asiatica (Madecassoside) (4%): Great for healing, reducing redness, and strengthening the skin barrier. Very suitable for acne and sensitive skin. Good concentration. (Product ID: 762)
• Carrot Extract (4%): Provides antioxidants. Generally fine, but ensure the specific extract type and concentration are suitable for cosmetic use at this level.
• Pomegranate Extract (3%): Antioxidant and anti-inflammatory. Good addition.
• Cucumber Extract (4%): Hydrating and soothing. Helps calm the skin. Good concentration. (Product ID: 219)
• Calendula Extract (3%): Known for its soothing and healing properties. Beneficial for irritated skin. Good concentration. (Product ID: 123)
• Witch Hazel Extract (10%): This is the ingredient that raises the most concern for sensitive skin. While it has astringent and anti-inflammatory properties, traditional Witch Hazel extracts often contain alcohol, which can be drying and irritating, especially at a high concentration like 10%. (Product ID: 333)
• Cyclopentasiloxane (8%): A silicone that provides a lightweight, smooth feel and helps with texture. It's generally non-comedogenic and suitable for acne-prone skin. (Product ID: 171)
• Phenostat (1%): A preservative blend. Its suitability depends on the exact components of "Phenostat". Ensure it is a blend known to be gentle for sensitive skin. 1% is a standard use level for many preservative blends.
• DI-Water (55%): The base of the serum.

Addressing Your Questions:

1. Will it be irritating? The primary concern for irritation, especially on sensitive skin, is the Witch Hazel Extract at 10%. If it contains alcohol, it is likely to be too drying and potentially irritating. The combination of many extracts, while individually soothing, could also potentially overwhelm extremely sensitive skin, but the chosen extracts are generally mild.
2. Is the pH suitable? The pH of the final mixture cannot be determined from the ingredient list alone. It must be measured after all ingredients are combined. For a serum applied to the skin, an ideal pH is typically between 4.5 and 5.5 to be compatible with the skin's natural pH. You will likely need to adjust the pH after mixing.
3. If adjustments are needed, where?
   • The most important adjustment for sensitive skin would be to reduce the concentration of Witch Hazel Extract or replace it with an alcohol-free version. A concentration of 2-5% might be more appropriate, or you could replace it with other soothing ingredients like Niacinamide (2-5%) or Panthenol (Vitamin B5) (1-3%).
   • Consider adding a dedicated humectant like Glycerin (2-5%) or Sodium Hyaluronate (0.1-0.5%) to boost the hydration properties further, as the current formula relies mostly on Aloe Vera and Cucumber for hydration.
   • Verify the specific components of "Phenostat" to ensure they are suitable for sensitive skin.
4. Is the texture lightweight enough for a serum? Yes, with 55% water and 8% Cyclopentasiloxane, the formula is likely to have a lightweight, non-greasy texture suitable for a serum. The silicone helps provide a smooth feel and aids spreadability.
5. How to mix? This is a general guide, always follow specific instructions for each raw material:
   • Ensure all equipment and containers are clean and sanitized.
   • Measure the DI-Water into a beaker.
   • Add the water-soluble extracts (Aloe Vera, Centella Asiatica, Carrot, Pomegranate, Cucumber, Calendula, Witch Hazel) to the water phase and stir until fully dissolved and homogeneous.
   • Add Phenostat (preservative) to the water phase and stir until fully incorporated.
   • Add Cyclopentasiloxane to the water phase and mix well. Ensure compatibility and that the mixture remains homogeneous.
   • Crucially, measure the pH of the final mixture using a pH meter or pH strips.
   • Adjust the pH to the desired range (4.5-5.5) using a dilute solution of an acid (like Lactic Acid or Citric Acid) or a base (like Sodium Hydroxide), adding drop by drop and mixing thoroughly before re-measuring.
   • Once the pH is adjusted and the mixture is homogeneous, you can filter it if necessary and package it into clean containers.

Conclusion:

The formula contains many excellent soothing and anti-inflammatory ingredients beneficial for acne-prone skin. The main point to reconsider for sensitive skin is the high concentration of Witch Hazel Extract. Always measure and adjust the pH, and perform a patch test before using the final product.