Simultaneous determination of sodium hyaluronate and gluconolactone in cosmetic products

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.

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.

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.

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.