Serum Formulation for Pigmentation: Ingredients, Texture, and Concentration

Question

I want to formulate a serum to be applied on skin where pigmentations are seen. I want to apply this before applying night serum with moisturizing properties.

I have a proposed formula:
1,3-Propanediol (Natural) 20%
Tranexamic Acid 3%
4MSK (Potassium Methoxysalicylate) 3%
AnyGel™ 1%
Safe B3 5%
Ethoxydiglycol 2.5%
Mild Preserve Eco 1%
Water 65%

I want to create sticky serum consistency. Is the combination of 1,3-Propanediol, AnyGel, and Water a good base for such serum?
I am not sure how much Ethoxydiglycol should be added to enhance the use of Safe B3. Please check.

Also, would it be advisable to use 1,3-Propanediol together with ALA? For example:

1,3-Propanediol: 90%
Alpha Lipoic Acid (ALA) (Powder): 10%

MySkinRecipes Expert · Accepted Answer

Serum Formulation Feedback

Here is some feedback on your proposed serum formulations for skin pigmentation:

Pigmentation Serum Formula (1,3-Propanediol, Tranexamic Acid, 4MSK, AnyGel, Safe B3, Ethoxydiglycol, Mild Preserve Eco, Water)

Consistency: Your proposed base using 20% 1,3-Propanediol, 1% AnyGel™, and Water will create a gel texture. 1,3-Propanediol at 20% acts as a humectant and will contribute to a hydrated feel, which may result in some tackiness or stickiness, aligning with your goal for a sticky serum consistency. AnyGel™ is a suitable gelling agent for this type of water-based serum.
Ethoxydiglycol and Safe B3: Ethoxydiglycol is an effective solvent and penetration enhancer for water-soluble ingredients like Safe B3 (Niacinamide) and Tranexamic Acid. Your proposed concentration of 2.5% Ethoxydiglycol is within the current regulatory limits for leave-on products and is a suitable amount to help improve the delivery and efficacy of these active ingredients in your serum.

1,3-Propanediol and Alpha Lipoic Acid (ALA) Formulation

Regarding your question about using 1,3-Propanediol with Alpha Lipoic Acid (ALA) at 90% and 10% respectively:

While 1,3-Propanediol can act as a solvent for ALA, the proposed concentrations are not advisable. The recommended usage rate for 1,3-Propanediol is typically up to 20%. More importantly, Alpha Lipoic Acid (ALA) is recommended for use at concentrations between 0.3% and 1.5% due to its potential to cause skin irritation, especially at higher levels. Using ALA at 10% is significantly above the safe and effective range and is highly likely to cause severe skin irritation.

For a formulation containing ALA, it is recommended to use ALA at a much lower concentration (0.3-1.5%) and formulate it with appropriate solvents within their recommended usage rates.