Characterization of Hydrogel Beads for the Gradual Release of Origanum vulgare L. Essential Oil and Evaluation of Their Antifungal Activity Against Candida albicans

Candida albicans infections are associated with high morbidity and mortality worldwide. Current antifungal therapies are limited by adverse effects and the emergence of resistant strains, which compromise long-term efficacy. Previous studies have shown that Origanum vulgare L. essential oil (OvEO) possesses strong antifungal activity; however, its volatility and physicochemical instability hinder clinical application. The aim of this study was to encapsulate OvEO in a hydrogel and evaluate its release kinetics, chemical composition, structural properties, and antifungal activity. We assessed its release kinetics, chemical composition, structural characteristics (FTIR; SEM), and antifungal activity against C. albicans. OvEO was successfully encapsulated into hydrogel beads, enabling a gradual release profile, with in vitro release of phenolic compounds reaching 100% at 48 min. SEM revealed an irregular surface with small pores and crystalline aggregates distributed across the bead surface. OvEO-loaded hydrogel beads inhibited C. albicans growth with an IC50 of 0.15 ± 0.05 mg/L for strain 90029 and 0.2 ± 0.06 mg/L for strain 10231. At these concentrations, adhesion to abiotic surfaces was reduced by 60–80%. These findings support the potential of OvEO-loaded hydrogel beads as an alternative approach for the treatment of fungal infections, offering a complementary strategy to current antifungal agents.