Cosmetics Formulation Development

Here are some questions about pH adjustment:

1. To put a buffer to adjust the product pH and want the pH of the product to be Stable, do I have to add both acid and salt of the acid? For example, put both Citric Acid - Sodium citrate or add only Sodium Citate if adding both. Approximately what is the ratio?

2. I would like to know if the product has reached the desired final pH such as pH 5.5, is it necessary to add a buffer such as sodium citrate or HEPES again? (out of the pH range of 5.5)

3. What step should I put buffer in? For example, put in the last step. Enter steps after adding Active, etc.

4. Do cosmetics need to contain buffers in every formula?

thank you

hello

Cosmetics do not always need to adjust the acidity or alkalinity, it is only necessary for some formulas that have a reason to control the pH.

For example, pH needs to be controlled because some ingredients are listed in the formula. It is stable only in the specified pH range.

The pH of the formula changes over time. This is usually caused by a breakdown of some of the ingredients in the formula. This may cause the pH to be lower or higher. In this case, it may be considered to adjust the pH value or use a buffer to help control the pH value.