How to Adjust pH in Your Formulation

Adjusting the pH of your cosmetic formulation is a common step to ensure stability, effectiveness, and skin compatibility. Based on the ingredients you are using, such as Active Resveratrol, which is most stable in a pH range of 3-6.5, a final product pH between 5.5 and 6.5 is generally recommended for optimal performance and skin comfort.

Here's how to adjust the pH if it's too low or too high:

If the pH is too Low (Acidic)

To increase the pH, you can use alkaline substances. Common options include:

• Sodium Hydroxide: Use a dilute solution (e.g., 10% solution in water) and add drop by drop to your formulation while stirring. Measure the pH after each addition until the desired range is reached. Do not exceed the recommended usage rate (typically 0.1-5% in the final formula, but use only what is needed to adjust pH). Avoid inhaling fumes.
• Triethanolamine 99%: Similar to Sodium Hydroxide, add drop by drop to increase pH. This is a liquid/gel form. Do not exceed the recommended usage rate (typically 0.1-2.5% in the final formula).

If the pH is too High (Alkaline)

To decrease the pH, you can use acidic substances. Common options include:

• Citric Acid (Anhydrous, Natural): Dissolve a small amount in water first. Add this dilute solution drop by drop to your formulation while stirring. Citric Acid changes pH very quickly, so add cautiously (e.g., 0.1g at a time) and measure the pH after each addition until the desired range is reached. The final product pH should not be lower than 3.0.
• Malic Acid (DL-Malic Acid): Also dissolves in water. Add gradually while stirring and measuring pH until the desired range is reached.

Important Tips:

• Always use a reliable pH meter or high-quality pH strips to measure the pH accurately.
• Add pH adjusters very gradually, stirring well after each addition, as a small amount can significantly change the pH.
• Measure the pH of the final product at room temperature.

By carefully adjusting the pH, you can ensure your formulation is stable and effective.