Formulation Issue: Precipitation with Nano Silver and Aristoflex AVC

You are observing white precipitation in your gel formulation containing Nano Silver Solution (ionic, 2000ppm) and Aristoflex AVC. This is not a normal or desired outcome for a stable cosmetic product.

Why Precipitation Occurred

The precipitation is likely due to an incompatibility between the ionic Nano Silver Solution (Silver Citrate and Citric Acid) and/or other electrolytes in your formula (such as 4MSK, which is Potassium Methoxysalicylate and noted as an electrolyte) and the Aristoflex AVC gelling agent.

Aristoflex AVC is a polymer that thickens the water phase of a formulation. However, these types of polymers can be sensitive to the presence of electrolytes or ingredients with positive charges. The ionic silver and the 4MSK are electrolytes, which can disrupt the gel network formed by Aristoflex AVC, causing the polymer to collapse and precipitate out as visible white particles.

The product description for the ionic Nano Silver Solution specifically advises avoiding electrolytes and positively charged ingredients in the formula to maintain stability.

Is it Safe to Use?

While the individual ingredients in your formula might be considered safe at the concentrations used, the presence of precipitation indicates that the formulation is unstable. Applying an unstable product with precipitated particles to the skin is not recommended. It may lead to:

• Reduced Efficacy: The active ingredients may not be evenly distributed or properly delivered to the skin.
• Potential Irritation: The precipitated particles could cause physical irritation to the skin.
• Poor Aesthetics: The product will not have the intended smooth gel texture.

Recommendation

To create a stable formulation, you would need to adjust your formula to avoid this incompatibility. This might involve:

• Using a different gelling agent that is compatible with electrolytes and ionic ingredients.
• Adjusting the order of addition of ingredients.
• Considering alternative forms of silver or other antimicrobial agents that are compatible with Aristoflex AVC.

It is best to discard the current batch that shows precipitation and reformulate using compatible ingredients to ensure a stable and effective product.