Stability of Beta Glucan and Licorice Extract in High pH Bar Soap
Question
I am trying to formulate a bar soap for facial cleansing using Beta Glucan and Licorice Extract. After making the soap, I measured the pH and it was around 11. I tried adding Citric Acid to lower the pH, but it didn't seem to change significantly.
My questions are:
1. Will Beta Glucan and Licorice Extract be effective when used in a bar soap with a high pH of 11?
2. Will these ingredients degrade or lose their benefits in such a high pH environment?
3. Is it possible to effectively incorporate these ingredients into a bar soap formulation, or should I consider other product types?
Answer
Using Beta Glucan and Licorice Extract in High pH Bar Soap
Regarding your question about making bar soap for facial cleansing with Beta Glucan and Licorice Extract, and finding that the pH remains high at 11 even after adding Citric Acid, here is an explanation.
Generally, bar soaps produced through the saponification process (reaction between fats and alkali) have a naturally high pH, typically in the range of 9-11. It is very difficult to significantly lower the pH of bar soap to a range suitable for the skin (around pH 5-6) or a range where active ingredients like Beta Glucan and Licorice Extract function effectively. Doing so can also affect the structure and stability of the soap bar.
Based on information about the active ingredients:
- Beta Glucan is generally recommended for use in formulations with a pH range of 5-7 for optimal stability and efficacy.
- Licorice Extract (especially water-soluble types) is often recommended for use in mildly acidic to neutral formulations, such as in the range of 3.5-6.5, to maintain the effectiveness of active compounds like Licochalcone A or Glabridin.
Therefore, adding Beta Glucan and Licorice Extract to a bar soap with a high pH of 11 is highly likely to cause these active ingredients to degrade and not provide their full benefits to the skin. Incorporating these ingredients into a high-alkaline, water-based environment typical of bar soap will likely destroy the active compounds, rendering their inclusion almost useless, as you suspected.
Attempting to lower the pH of bar soap with Citric Acid is also challenging because of the high amount of alkali present. Adding a small amount of acid may not significantly change the pH, and adding too much can cause the soap to crumble or lead to other issues.
Alternative Solutions:
If you wish to effectively utilize the benefits of Beta Glucan and Licorice Extract in a facial cleansing product, you should consider changing the product format from a bar soap to other forms where the pH can be controlled more easily and is suitable for these active ingredients, such as:
- Cleansing Gel
- Cleansing Foam
- Cleansing Cream
These types of cleansing products can be formulated to a pH range that is compatible with the skin (Skin pH) and where active ingredients like Beta Glucan and Licorice Extract are stable and effective. This will ensure that the ingredients you add provide real benefits to the skin.
