Simultaneous determination of sodium hyaluronate and gluconolactone in cosmetic products.

Abstract

Objective: The increasing prevalence of sodium hyaluronate and gluconolactone in a wide range of cosmetic formulations has created a crucial need for robust and reliable analytical methods to ensure product quality, optimize formulations and meet regulatory standards. Sodium hyaluronate and gluconolactone, two highly sought-after humectants renowned for their remarkable water-binding properties, present significant analytical challenges during quantification. Sodium hyaluronate, a complex polymeric structure, lacks a UV-absorbing chromophore and gluconolactone needs an indirect technique (derivatization/conversion to gluconic acid) to be quantified, which makes these analyses quite challenging in cosmetic products.

Method: This study directly addresses this critical gap in cosmetic analysis by developing and validating a novel method for the simultaneous determination of sodium hyaluronate and gluconolactone in cosmetic compositions. This method employs size exclusion liquid chromatography (SEC), a powerful separation technique ideal for analysing polymers and macromolecules, coupled with sensitive UV detection. Using a BioSep SEC S2000 column and an isocratic mobile phase of 0.05 M potassium dihydrogen phosphate (pH 7.0), we achieved efficient separation and detection at 205 nm, enabling the quantification of both compounds despite the absence of strong chromophores.

Results: Rigorous method validation confirmed the reliability and robustness of this approach. The method demonstrated excellent linearity (r² > 0.999) over a wide concentration range of 25-1000 μg/mL for both sodium hyaluronate and gluconolactone, ensuring accurate quantification across diverse formulation concentrations. Additionally, high precision (RSD ≤1.22%), specificity against common cosmetic excipients and satisfactory recovery rates (80%-120%) further validate the method's suitability for routine quality control analysis in the cosmetic industry.

Conclusion: This sensitive, accurate and robust SEC-UV method provides a valuable new tool for cosmetic manufacturers to ensure the quality, efficacy and consumer safety of products containing these key ingredients.