Characterization of the inclusion complex of the essential oil of Lantana camara L. and beta-cyclodextrin by vibrational spectroscopy, GC-MS, and X-ray diffraction

The genus Lantana is widely used in folk medicine because its essential oil has antibacterial, antifungal and repellent activity. However, its thermal instability and low solubility in water reduce its technological application. In this work, an inclusion complex was prepared consisting of the essential oil of Latana camara L. (LCEO) and beta-cyclodextrin (beta-CD). The complex was characterizated by vibrational spectroscopy (Raman and FTIR spectroscopy), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The optimization of the ratio of the LCEO and beta-CD in the inclusion complex was determined by gas chromatography coupled to mass spectrometry (GC-MS); it was inferred that the ratio of guest-host = 6:94 (m:m) was the optimal ratio. Shifts in some peak positions of the vibrations modes in Raman spectra of L. camara and beta-CD provided clearer and better evidence of inclusion complex formation than infrared spectroscopy did. Results of DSC and XRD characterization of inclusion complex are in good agreement with Raman results.