The volatilization stability, mechanical property and sustained-antibacterial effect of solidified Artemisia argyi leaf essential oil by porous carriers

Essential oil of Artemisia argyi leaf (AAEO), derived from a well-known herb plant species of Compositae family, is extensively used to develop healthcare products in traditional medicine and incense for its aromatic odour. In an effort to address the main challenges associated with essential oil, i.e., high volatilization and poor sustainability, we have screened and prepared solidified AAEO powders using six carriers with distinct structural characteristics, including non-porous fumed silica, functionalized mesoporous silica, magnesium aluminometasilicate and calcium carbonate, two ordinary excipients including starch and β-cyclodextrin (β-CD). Substantial evaluation was conducted on the volatilization stability, mechanical property and biological activity as well. Compared to starch and β-CD, more excellent solid-state properties for 350FCP-, S244-, US2-AAEO displayed on dry, loose appearance and high loading amount, extremely reduced weight loss and alleviated the volatilization by TG, DSC and kinetic analysis. BET and BJH methods were employed to evaluate the surface area and pore characteristic of the mesoporous materials microstructure. The solidification of AAEO effectively reduced the volatilization, thus improved the potential stability of volatile oil, particularly for S244 at high temperature. 350FCP- and S244-AAEO powders reflected a significant improvement on the flowability, packability and tabletability, while US2-AAEO behavior was much sensitive to AAEO loading content. This was likely attributed to its spherical morphology with SEM and greater distribution of hydrogen-containing molecules by LF NMR analysis. Through GC-MS analysis of components and antibacterial activity against E. coli , 350FCP- and S244-AAEO especially proved to alleviate the volatilization rate of 23 major ingredients, such as thujone, eucalyptol, caryophyllene, and germacrene D, and simultaneously prolonged the antibacterial effect over 7 days. These comprehensive assessments provided the strong protection for the volatile stability and sustained biological activity to utilize a feasible porous silica material for developing technique for essential oils. • Porous carrier-based solidification was developed to stabilize volatile Artemisia argyi essential oil (AAEO). • S244, 350FCP, and US2 carriers reduced AAEO volatilization by 16.5% to 45.6% within 24 h at 60 °C. • Optimized powders exhibited markedly improved flowability and tabletability for potential product development. • Solidified AAEO powders prolonged antibacterial efficacy against E. coli through sustained release. • This work provides a feasible strategy for stabilizing essential oils using porous silica carriers.