Formula Analysis: pH, Preservatives, and Ingredient Function

Question

I have a formula containing 10% Lactic Acid, Yogurt Extract, Fruit Blend Extract, Tamarine Extract, Cucumber Extract, Polysorbate 20, and Raspberry Fragrance. I plan to add 1% Phenoxyethanol as a preservative.

1. What is the estimated pH of this formula with 10% Lactic Acid?
2. Will adding 1% Phenoxyethanol cause the extracts (Yogurt, Fruit Blend, Tamarine, Cucumber) to degrade?
3. Is Phenoxyethanol suitable as a preservative for this formula, considering the pH? If not, what other preservatives are suitable for low pH?
4. Based on the ingredients listed, what are their functions, and what recommendations do you have for reducing, increasing, or removing any ingredients?
5. Can Vitamin B3 alone help with skin whitening without Glucosamine?
6. What is the difference between Glydant (DMDM Hydantoin) and Phenoxyethanol?
7. Where can I buy Glydant (DMDM Hydantoin)?

MySkinRecipes Expert · Accepted Answer

Formula Analysis and Answers

Based on your formula and the discussion:

Estimated pH: With 10% Lactic Acid, the pH of your formula is expected to be quite low, likely below 3.5. To know the exact pH, you would need to measure it directly using a pH meter or pH strips.
Phenoxyethanol and Extracts: Adding 1% Phenoxyethanol will not cause the extracts in your product to degrade. Phenoxyethanol is compatible with these ingredients.
Preservative for Low pH: Phenoxyethanol is effective in a pH range of 3-9. If your formula's pH is below 3, its effectiveness might be reduced. For formulas with a pH below 3.5, you should consider preservatives that are effective in a lower pH range. Some options suitable for low pH include Global Guard™ 221 (effective at pH 2-7) and Mild Preserved™ COS (effective at pH 2-8).
Formula Adjustments: Providing specific recommendations on which ingredients to reduce, increase, or remove requires understanding the desired final properties and goals for your product. Each ingredient in your formula serves a purpose:
- Lactic Acid (AHA) is for exfoliation.
- Yogurt Extract, Fruit Blend Extract, Tamarine Extract, and Cucumber Extract provide various benefits like moisturizing, skin tone evening, brightening, and soothing.
- Polysorbate 20 acts as a solubilizer for the fragrance and provides slip.
- Raspberry Fragrance adds scent.
  
  Adjusting these would depend on which benefits you want to emphasize or if you encounter stability issues.
Vitamin B3 Alone for Whitening: Yes, Vitamin B3 (Niacinamide) can help with skin whitening and brightening even without Glucosamine. Products like Safe-B3™ and Extreme-B3™ contain Niacinamide which is known for its ability to improve skin tone and reduce hyperpigmentation.
Glydant vs. Phenoxyethanol: Glydant (DMDM Hydantoin) and Phenoxyethanol are different types of preservatives. DMDM Hydantoin is a formaldehyde-releasing preservative, which has raised safety concerns and is restricted or banned in several countries. Phenoxyethanol is a widely used preservative that does not release formaldehyde.
Where to buy Glydant (DMDM Hydantoin): DMDM Hydantoin is available, but its use is generally not recommended due to the safety concerns mentioned.