Understanding the Precipitation

Based on the information from your question and the staff's replies, the precipitation you observed in your formula containing Salicylic Acid EZ and Witch Hazel, and later with added Pro Polymer, is due to Salicylic Acid EZ being used in a liquid base.

Salicylic Acid EZ is designed to be stable and fully dissolved when incorporated into a gel or cream base, not a thin liquid like Witch Hazel or plain water. When used in a liquid formula, especially at a high concentration like 10%, it can precipitate or crystallize over time, particularly with changes in temperature.

Fixing a Precipitated Batch

Unfortunately, once Salicylic Acid EZ has precipitated in your formula, it cannot be fully restored to a stable, dissolved state. While heating might temporarily make the crystals disappear, they are likely to reform. The staff advises against using a product that has precipitated, as the uneven distribution of Salicylic Acid can cause increased skin irritation and reduced effectiveness. The affected batch should be discarded.

Preventing Precipitation in Future Batches

To prevent precipitation when using Salicylic Acid EZ, you must create a gel or cream texture from the very beginning of the formulation process. The recommended method is to add a gelling agent like Pro Polymer to the water phase before adding Salicylic Acid EZ and other ingredients like Vitamin B3 and Vitamin B5.

A suggested formulation approach is:

1. Combine water and Salicylic Acid EZ, ensuring the Salicylic Acid EZ is fully dissolved and the solution is clear.
2. Add Vitamin B3 and Vitamin B5 and mix until dissolved.
3. Slowly add Pro Polymer (typically 1%) while mixing to create a gel texture. Continue mixing until a smooth gel is formed and the Pro Polymer is fully hydrated.

It is crucial to establish the gel structure first to properly stabilize the Salicylic Acid EZ and prevent it from crystallizing out of the solution. Adding the gelling agent after precipitation has already occurred will not fix the issue.