Encapsulation of Eucalyptus radiata Essential Oil in β‐Cyclodextrin (β‐CD): Formulation and Characterization of the Inclusion Complexes

The main objective of the present research was the formulation and characterization of inclusion complexes (ICs) involving Eucalyptus radiata essential oil (EREO) in β‐cyclodextrin (β‐CD). GC‐MS analysis was used to identify the chemical composition of the oil, while the effectiveness of the encapsulation was evaluated on the basis of process yield, complexation efficiency (CE), and phase solubility studies. The resulting solid EREO‐βCD‐ICs were characterized using FT‐IR, powder XRD, TGA, and SEM analysis. Their antioxidant and antibacterial activities were also evaluated. The GC‐MS analysis revealed that eucalyptol was the main compound (39.6%), followed by p‐cymene (14.2%) and o‐cymene (8.4%). Among the tested methodologies, the co‐precipitation provided superior complexation efficiency of 87.73%, whereas the kneading technique achieved complexation efficiency of 79.72%. The obtained FTIR spectra, x‐ray diffraction patterns, TGA curves and SEM micrographs of inclusion complexes prepared by different methods suggest that the essential oil was effectively encapsulated within the β‐CD cavity, leading to the formation of stable inclusion complexes with improved thermal stability of the encapsulated essential oil. Furthermore, the inclusion complex showed greater antioxidant and antibacterial activities compared to the free EREO. In conclusion, β‐CD encapsulation makes EREO a promising candidate for pharmaceutical and food applications.