Development and Characterization of Alginate Hydrogel Beads Containing Tanacetum vulgare Extract

Tanacetum vulgare L. (Common tansy) contains a high concentration of biologically active compounds, such as phenols, terpenes, and flavonoids, that act as anti-inflammatory, antimicrobial, and antioxidant agents. Hydrogel beads can be used to encapsulate these biologically active components to ensure their stability and targeted intestinal delivery. The aim of this preliminary study was to develop sodium alginate hydrogel beads incorporating lyophilized T. vulgare leaf extract in different concentrations and perform physicochemical and structural analyses to determine the possibility of further developing T. vulgare-containing hydrogels for targeted intestinal delivery of polyphenols. The development of 2% sodium alginate hydrogel beads using extrusion and ionic crosslinking with a 1.5% calcium chloride solution was successful. Beads presented amorphous, viscoelastic, non-thixotropic behaviour and hydrogen bonding with polyphenols from T. vulgare extract. Alginate crosslinking exceeded 78%. Encapsulation of chlorogenic acid equivalents (CGAEs) was on average 28.4% to 39.3%. Beads degraded in pH 6.8 and 7.4 within 24 h, releasing up to 80.1% of encapsulated CGAEs. The highest antiradical activity was 5.5% per gram of beads, with the half-maximal inhibitory concentration (IC50) of the T. vulgare extract being 250 μg/mL. This information can be used to further develop alginate hydrogel beads containing T. vulgare leaf extract.