Solubility and Recrystallization of Standard Salicylic Acid in 1,3-Propanediol

Regarding the solubility of standard Salicylic Acid in 1,3-Propanediol:

1. It is correct that standard Salicylic Acid is difficult to dissolve and is prone to recrystallization, which can reduce its effectiveness. This is a characteristic of the standard form, regardless of the supplier.
2. While glycols like 1,3-Propanediol can dissolve some Salicylic Acid, they are generally less effective solvents for the standard type compared to alcohols (like ethanol or isopropyl alcohol), especially at higher concentrations.
3. Therefore, using 1,3-Propanediol as the primary solvent for standard Salicylic Acid can indeed lead to recrystallization, particularly over time or with temperature changes, as the other seller advised.
4. There are no simple techniques using only 1,3-Propanediol that can reliably prevent recrystallization of the standard type, especially at typical cosmetic usage concentrations. Heating can help initial dissolution, but it may still recrystallize upon cooling.

For stable solutions without recrystallization, particularly for leave-on products, using the more easily soluble or encapsulated forms of Salicylic Acid (like Salicylic Acid EZ™, Encapsulated Salicylic Acid) is the most reliable approach, as previously recommended by our staff. If you must use the standard type, using alcohol as a primary solvent or incorporating a specific solubilizer designed for Salicylic Acid would be more effective than relying solely on 1,3-Propanediol to prevent recrystallization.