Eyelash Growth and Strengthening Serum Formulation Advice

The formulation you've designed for eyelash nourishment and growth appears to combine several ingredients with complementary mechanisms of action.

Ingredient Functions and Overlap

• Long-Lash™, Biotinyl-GHK, and Melatonin Forte™ are key actives aimed at stimulating eyelash growth and reducing shedding through different pathways.
• Biotin supports hair health, growth, and strength.
• Panthenol (Vitamin B5) provides essential nourishment and moisture to the lashes.
• Urea enhances the penetration of Biotin.
• Dimethyl Isosorbide (DMI) acts as a general penetration enhancer for water-soluble ingredients in your formula.
• Triacetin stabilizes Urea.
• Mild Preserved Eco™ provides preservation and some moisturizing benefits.
• Pro Polymer™ creates the gel texture.

The active ingredients primarily work through distinct or complementary mechanisms, making their combination potentially beneficial for a multi-faceted approach to eyelash enhancement.

Role of Triacetin

According to the product description, Triacetin is soluble in water, alcohols, organic solvents, and aromatic hydrocarbons. Its primary role in your formula, especially in conjunction with Urea, is to help stabilize the Urea and prevent the pH from rising over time, thus maintaining the formula's stability and the effectiveness of Urea. Based on the product information, it should dissolve in the water phase of your formulation.

Incorporating Triacetin

Since the product description indicates Triacetin is water-soluble, it should be mixed into the water phase. You do not necessarily need an additional emulsifier specifically for Triacetin if it dissolves completely in the water phase. Pro Polymer™ is a gel maker and thickener, not an emulsifier, and its function is to create the gel structure of the formula.

Dimethyl Isosorbide (DMI)

Dimethyl Isosorbide (DMI) is an effective penetration enhancer for water-soluble ingredients, which can help the active ingredients like peptides, melatonin, biotin, and panthenol better absorb into the skin at the base of the eyelashes. Based on product examples that use DMI in eye serums and creams, it is considered suitable for use in formulations applied near the eye area. However, as with any ingredient, it's always recommended to perform stability and safety testing for your specific final formulation, especially for a sensitive area like the eyes.

Your planned formulation incorporates several well-regarded ingredients for eyelash care. Ensure you follow the recommended usage rates and mixing instructions for each ingredient, paying particular attention to the stability requirements for Melatonin and Biotin.