Formulation Compatibility and Mixing

1. Ingredient Compatibility

The ingredients you have chosen have many beneficial properties for acne-prone skin, such as anti-inflammatory effects from Willow Bark Extract, Madecassoside, and Licorice Extract, moisturizing from Rose Water, 4D Hyaluronic Acid, and MOIST72, skin barrier support from Prebio-care, and potential antibacterial effects from Tea Tree Oil and Nano Silver Solution. Laurocapram is included as a penetration enhancer.

However, there is a significant compatibility issue with the Nano Silver Solution (Ionic type) you selected. The description for this ingredient explicitly states that it cannot contain cationic surfactants or any ingredient that has a positive charge, and you should avoid all types of salt/electrolyte in the formula as it may affect stability and cause precipitation.

Your formula includes:

• 4D Hyaluronic Acid, which contains Hydroxypropyltrimonium Hyaluronate, a cationic (positively charged) form of hyaluronic acid.
• MOIST72™, which is preserved by Citric Acid and Sodium Citrate (a salt).
• The Silky Serum Base description recommends adding 1% NaCl (salt) or Magnesium Sulfate (salt) for stability.

The presence of the cationic 4D Hyaluronic Acid and the salt in MOIST72™ (and potentially added salt for the base) will cause the ionic Nano Silver Solution to precipitate or become unstable. Therefore, the ingredients as listed are not compatible due to the conflict with the Nano Silver Solution.

2. Modifying the Formula to an Essence

If you remove the Silky Serum Base and increase the Rose Water to 72% to make an essence, this will change the texture and remove the potential issue of adding salt for the base's stability. However, the formula would still contain 4D Hyaluronic Acid (with its cationic component) and MOIST72™ (with its salt preservative).

Since these incompatible ingredients remain in the formula, removing the Silky Serum Base and increasing the Rose Water will not prevent the Nano Silver Solution from precipitating.

To include Nano Silver Solution (Ionic type) in a formula, you would need to ensure that no cationic ingredients or salts/electrolytes are present. Alternatively, you might need to consider a different type of silver ingredient or a different preservative system altogether that is compatible with all other chosen ingredients.

3. Mixing Order and Precautions

Assuming you adjust the formula to resolve the Nano Silver incompatibility (e.g., by removing Nano Silver or replacing incompatible ingredients), here is a general mixing order and precautions for the other ingredients, based on their descriptions:

General Mixing Order:

1. Combine the main water phase (Rose Water).
2. Add water-soluble ingredients that don't require specific late-stage addition or have heat sensitivity limits above room temperature: Willow Bark Extract, Prebio-care, Licorice Extract, Tea Tree Oil (Water Soluble). Mix until fully dissolved.
3. Add 4D Hyaluronic Acid. Mix thoroughly until the gel is homogeneous.
4. Add Laurocapram (Water Soluble). Mix well.
5. If using the Silky Serum Base, gradually add the water phase mixture to the Silky Serum Base while stirring continuously until a homogeneous serum texture is achieved. (Note: The base description suggests adding water to the base gradually).
6. Once the mixture is homogeneous and has cooled (below 40°C), add Madecassoside and MOIST72™. Mix gently until dispersed/dissolved.
7. Adjust the pH of the final formula to be within the compatible range for most ingredients (ideally between 4.0 and 6.5).
8. If you were using Silky Serum Base and not including Nano Silver, you could add 1% salt (NaCl or Magnesium Sulfate) at the end for stability and mix until dissolved.

Precautions:

• Temperature: Avoid exposing the mixture to high heat. Specifically, keep the temperature below 60°C when mixing Laurocapram, and below 40°C when adding MOIST72™. Madecassoside and Willow Bark Extract should also avoid heat.
• pH: Ensure the final pH of the formula is within the optimal range for the ingredients, generally between 4.0 and 6.5 for this combination (excluding the incompatible Nano Silver).
• Mixing: Mix each ingredient thoroughly until fully dissolved or dispersed before adding the next. When mixing the Silky Serum Base with the water phase, add the water phase gradually to the base with good stirring.
• Nano Silver Incompatibility: As noted above, the ionic Nano Silver Solution (ID 7432) is incompatible with cationic ingredients (like the one in 4D Hyaluronic Acid) and salts (like the one in MOIST72™ and potentially added for Silky Serum Base stability). Do not include Nano Silver Solution (ID 7432) in this specific formulation.

To create an effective formula for your daughter's skin concerns, you might consider adjusting the ingredients based on the compatibility issues identified, particularly regarding the Nano Silver Solution.