Salicylic Acid Precipitation in Formula and Solution

Based on the conversation, the precipitation in your formula is likely due to the type of Salicylic Acid used.

The staff explained that regular Salicylic Acid requires a very high amount of solvent like Propylene Glycol or Butylene Glycol to dissolve completely (about 15-20 times the amount of Salicylic Acid). Your formula uses 1.8% regular Salicylic Acid but only 2% Butylene Glycol, which is not enough to dissolve it, causing it to precipitate.

The staff recommended using Salicylic Acid EZ instead because it is water-soluble and will dissolve easily in your formula without needing a large amount of glycol solvent.

Therefore, to fix the precipitation issue, you should replace the regular Salicylic Acid with Salicylic Acid EZ at the same percentage (1.8%).