Serum Formulation Review and Advice

Thank you for sharing your serum formulation and questions. It's a comprehensive formula with many beneficial ingredients. Here's a review and some advice based on your questions:

1. Ingredient Compatibility

Your formula contains a wide variety of ingredients, including oil-soluble vitamin C (perfect c), various extracts, peptides, hydrators, barrier repair ingredients, and thickeners/emulsifiers. While many of these ingredients are generally compatible, combining such a large number of active ingredients at high concentrations can pose challenges for long-term formula stability. It's highly recommended to perform stability testing on your finished product to ensure the texture remains consistent, the color doesn't change, and the efficacy is maintained over time.

2. Desired Light Texture (Silk Lotion Maker vs Xanthan Gum)

• Xanthan Gum is a thickener used in the water phase. It helps increase viscosity and can create a gel-like serum texture.
• Silk Lotion Maker is an emulsifier that helps combine oil and water phases to create emulsion textures like lotions or light creams.
• Your formula includes perfect c, which is an oil-soluble vitamin C derivative. To effectively incorporate perfect c into the predominantly water-based formula and prevent separation, an emulsifier like Silk Lotion Maker is likely needed to create a stable, light emulsion serum.
• Using Xanthan Gum alone might not be sufficient to keep the oil-soluble perfect c evenly dispersed and stable in the water phase, potentially leading to separation.
• Therefore, using Silk Lotion Maker in combination with Xanthan Gum, or using Silk Lotion Maker alone in an appropriate amount, may help achieve a stable, light emulsion serum texture. The specific ratio will depend on the overall oil and water content.

3. Including Water Lock in Serum

• Water Lock (Polyquaternium-51) is an ingredient that provides hydration and forms a thin film on the skin to reduce moisture loss.
• You can definitely include Water Lock in your serum to enhance hydration and give the skin a smooth feel.
• Generally, Water Lock at the concentration used in cosmetic formulas (2% in your formula) is not expected to form a film thick enough to significantly hinder the absorption of subsequent creams. It often provides a pleasant, non-tacky feel and can even help other products layer better.
• Whether to include Water Lock in the serum or a cream depends on your preference. If you want the serum to be a primary source of hydration and skin conditioning, including it in the serum is appropriate.

4. Adding More Ingredients for Effectiveness

Your current formula is already very comprehensive and targets multiple skin concerns (brightening, anti-aging peptides, hydration, barrier repair, soothing). Adding more active ingredients may not necessarily provide a significant boost in efficacy but could increase formulation complexity and potentially the risk of irritation.

It's recommended to start with this formula, observe the results, and then consider adjustments if needed.

5. pH Adjustment with Citric Acid

• Adjusting the pH of your cosmetic formula is important for optimal efficacy, stability, and skin compatibility of the ingredients.
• Many ingredients in your formula, such as the peptides, are stable and effective within a pH range of approximately 4-7.
• A pH of around 5-6 is generally close to the skin's natural pH (around 4.5-5.5) and is well-tolerated.
• Citric Acid is a commonly used pH adjuster.
• Therefore, it is recommended to measure the pH of your finished formula and adjust it to approximately 5-6 by adding Citric Acid gradually until the desired pH is reached.

Additional Tips for Beginners:

• Formulating complex formulas like this requires precision in weighing and following correct mixing procedures.
• Start by making a small batch to test the texture and stability.
• Maintain cleanliness of your equipment and workspace to prevent contamination.
• Observe changes in the texture, color, and smell of your product over time to assess stability.

Hope this information is helpful for your serum making! Feel free to ask if you have more questions.