Combining BHA and DMAE in Serum: pH and Stability Issues

Combining BHA (Salicylic Acid) and DMAE in the same serum formulation at a pH of 3.6 presents several challenges due to the chemical properties of these ingredients.

Here's a breakdown:

• BHA (Salicylic Acid): For BHA to be effective as an exfoliant and penetrate the skin well, it needs to be in an acidic environment, typically within a pH range of 3 to 4. A pH of 3.6 is ideal for BHA.
• DMAE (Dimethylaminoethanol): DMAE is an amine, which means it is basic. It is generally more stable and effective at higher pH levels, typically in the neutral to slightly alkaline range (around pH 6-8).
• Combining Acid and Base: When you combine an acidic ingredient like BHA with a basic ingredient like DMAE, they will react and neutralize each other. This reaction will raise the pH of the solution.
• Maintaining pH 3.6: Adding DMAE to an acidic BHA solution will increase the pH. To then bring the pH back down to 3.6 would require adding an acid, not TEA. TEA (Triethanolamine) is also a base and is used to increase the pH of a solution. Using TEA after adding DMAE would further increase the pH, moving it away from the required 3.6 for BHA.
• Ingredient Stability and Efficacy: Even if you could somehow maintain the pH at 3.6, DMAE is a base and may not be stable or optimally effective at such a low pH. The low pH required for BHA is not suitable for DMAE.
• Formulation Stability: Combining ingredients with such different optimal pH ranges can lead to formulation instability issues, such as precipitation, cloudiness, or degradation of the active ingredients over time.

Therefore, while you can physically mix them, it is generally not recommended to combine BHA and DMAE in the same formulation, especially when targeting the low pH required for BHA efficacy. It is very difficult to ensure the stability and effectiveness of both ingredients simultaneously at pH 3.6.

It would be better to use products containing these ingredients separately or consult with a cosmetic chemist who can formulate a complex system designed to handle ingredients with disparate pH requirements, which is often challenging.