Journal de biochimie et de physiologie

Impact of Poly-L-Lysine Dendrimers on the Stability and Effectiveness of Vitamin C in Dermocosmetic Use

Bertrand Nassar and Hafid Belhadj-Tahar*

This study explores the stabilization and efficacy enhancement of vitamin C in dermocosmetic formulations through its association with Poly-L-lysine dendrimers. Vitamin C, critical for collagen synthesis and skin hydration, faces challenges due to its instability and low bioavailability. The research aims to evaluate the liposolubility of vitamin C (Ko/w) in the presence of Poly-L-lysine vectors, assess its stability in both aqueous and emulsion media and determine the moisturizing efficacy of second-generation Poly- L-lysine (diameter: 4.5 nm, PM: 8.6 kDa) and third-generation Poly-L- lysine (diameter: 7 nm, PM: 22 kDa).

Materials and Methods: Methods included High-Performance Liquid Chromatography (HPLC) for concentration analysis, partition coefficient determination (Ko/w), and stability assessments under various conditions. Hydration potential and kinetics were evaluated on 11 volunteers using a corneometer.

Results: The liposolubility (Ko/w) of vitamin C increased by over 300% with Poly-L-lysine, enhancing its stability. Emulsion stability tests confirmed that formulations with Poly-L-lysine maintained their physical and chemical properties under stress conditions. Physiological tests showed significant improvements in skin hydration with the Poly-L-lysine/ vitamin C formulations, achieving 66.2% hydration increase at T3hours for third-generation dendrimers.

Conclusion: In conclusion, Poly-L-lysine vectors significantly enhance the stability and moisturizing efficacy of vitamin C in dermocosmetic formulations. These findings suggest that Poly-L-lysine can reduce vitamin C’s instability and improve its dermocosmetic benefits, offering a promising approach for advanced skincare solutions.