Recommended pH Adjusters

Several bases can be used to increase the pH of your essence. Considering your sensitive skin and the need for pH stability for your ingredients, here are a few options:

• Tromethamine (TRIS): This is an excellent option as it acts as both a pH adjuster and a buffer. Buffers help to stabilize the pH, which is particularly important for ingredients like GHK-Cu that require a specific pH range (4.5-7.4). It is generally considered gentle and is used at a low rate (0.1-1.0%).
• Sodium Hydroxide: A very effective and common pH adjuster. It's potent, so only a small amount is needed. It's important to handle Sodium Hydroxide carefully and always add it to water (not the other way around) to dissolve it before adding to your formulation. Use rate is 0.1-5%.
• Triethanolamine 99%: Another common alkaline agent for pH adjustment. The high purity version is recommended. Use rate is 0.1-2.5%. The product description notes that AMP offers better stability in some formulations compared to Triethanolamine.
• AMP (2-Amino-2-methyl-1-propanol): You mentioned concern about phototoxicity. While the product description doesn't specifically address this, it's a valid consideration for sensitive skin. AMP is effective for pH adjustment (0.1-5%) and is noted for providing good formulation stability. If you are concerned about potential phototoxicity, especially with sensitive skin, opting for Tromethamine or Sodium Hydroxide might be preferable.

For your formulation containing GHK-Cu and Vitamin B6, maintaining the correct pH is crucial for their stability and efficacy. GHK-Cu is stable in the pH range of 4.5-7.4, while Vitamin B6 is stable between pH 2-6. Adjusting your essence to a pH within the 4.5-6 range would be ideal to ensure both ingredients remain stable.

When and How to Mix the Base

The best time to adjust the pH of your essence is at the very end of your formulation process, after all other ingredients have been fully incorporated and the mixture has cooled (if heat was used).

Here's the general method:

1. Prepare a dilute solution of your chosen pH adjuster (e.g., dissolve a small amount of Sodium Hydroxide or Tromethamine powder in distilled water, or use the liquid form of Triethanolamine or AMP).
2. Add the dilute base solution to your essence very slowly, drop by drop or in small increments.
3. After each addition, mix the essence thoroughly to ensure the base is evenly distributed.
4. Use a calibrated pH meter to check the pH of the essence.
5. Continue adding the base solution gradually, mixing, and checking the pH until you reach your desired target pH, ideally between 4.5 and 6 for the stability of GHK-Cu and Vitamin B6.

Adding the base at the end ensures that you are adjusting the pH of the final mixture and that pH-sensitive ingredients like GHK-Cu (which should be added below 40°C in the final step) are exposed to the correct pH range only after they are incorporated.

In summary, Tromethamine (TRIS) is a strong candidate due to its buffering ability, which helps maintain pH stability for your sensitive ingredients. Sodium Hydroxide is also effective but requires careful handling. Always adjust pH gradually at the end of your formulation process using a pH meter to ensure accuracy and stability.