Custom Whitening Serum Formulation Stability at pH 4

Thank you for submitting your formula for review for the production of a whitening serum. We have reviewed the formula and your requirements for a slightly viscous serum texture and a pH of around 4.

Based on our initial assessment, the proposed formula presents challenges in achieving stability according to your specifications, particularly at a pH of around 4. This is because several ingredients in the formula, such as Niacinamide (Safe-B3™) and the gel-forming agent Pro Polymer™, have optimal pH ranges for function and stability that are higher than this.

• Niacinamide (Safe-B3™): Is generally most stable in the pH range of 5-7. In highly acidic conditions (low pH), it can hydrolyze into Nicotinic acid, which may cause skin irritation.
• Pro Polymer™: Is a gel-forming agent that requires a higher pH (typically around 5-7) to effectively create a gel structure and increase viscosity. At pH 4, gel formation may be difficult or incomplete, making it challenging to achieve the desired slightly viscous serum texture.
• Other Ingredients: Many other active ingredients and components in the formula may have different optimal pH ranges. Combining a large number of ingredients in a single formula at a low pH can increase the risk of interactions between them, leading to the degradation of some active ingredients or overall formula instability.

Therefore, the formula as proposed may not be feasible for stable production and achieving the desired results at pH 4. Significant modifications are necessary, potentially including adjusting the pH to a range more suitable for most ingredients (e.g., pH 5-6) and/or changing the thickening system to achieve the desired texture at that pH.

For the suitability and stability of the final product, we recommend consulting with our formulation experts to make the necessary adjustments to the formula for practical production and maximum efficacy.