An Improved Nanoemulsion Formulation Containing Kojic Monooleate: Optimization, Characterization and In Vitro Studies

Area of Science:

• Cosmetic Science
• Materials Science
• Biochemistry

Background:

• Hyperpigmentation treatment necessitates effective tyrosinase inhibitors.
• Kojic monooleate (KMO), derived from kojic acid and oleic acid, demonstrates superior depigmenting potential compared to kojic acid.
• Nanoemulsions offer enhanced delivery and efficacy for cosmetic agents.

Purpose of the Study:

• To optimize the production parameters for Kojic monooleate (KMO) nanoemulsions using Response Surface Methodology (RSM).
• To evaluate the physicochemical properties, safety, and efficacy of the optimized KMO nanoemulsion.
• To assess the potential of KMO nanoemulsion as a cosmetic agent for hyperpigmentation management.

Main Methods:

• Response Surface Methodology (RSM) was employed to optimize high shear speed, high shear time, and stirrer speed.
• Physicochemical characterization included droplet size analysis, pH, conductivity, and stability testing (centrifugation, accelerated storage).
• In vitro efficacy was assessed by tyrosinase inhibition assays, and safety was evaluated through cytotoxicity assays (IC50 determination).

Main Results:

• Optimized formulation parameters yielded a KMO nanoemulsion with a droplet size of 103.97 nm.
• The optimized nanoemulsion exhibited a pH of 5.75, high conductivity (3.98 mS/cm), confirming oil-in-water type.
• The nanoemulsion demonstrated excellent stability over 90 days across various temperatures and showed low toxicity (IC50 > 500 μg/mL) while inhibiting 67.12% of tyrosinase activity.

Conclusions:

• The optimized KMO nanoemulsion formulation is stable, safe, and possesses significant tyrosinase inhibitory activity.
• KMO nanoemulsions represent a promising approach for developing effective and safe cosmetic agents for treating hyperpigmentation.
• The study validates RSM as a suitable method for optimizing nanoemulsion formulations for cosmetic applications.