Characterization of Inclusion Complex of Croton zehntneri Essential Oil and β-Cyclodextrin Prepared by Spray Drying and Freeze Drying

Croton zehntneri (CZ) is an aromatic species of the Euphorbiaceae family, native to Northeast of Brazil, rich in essential oil (CZEO) with antioxidant, vasorelaxant, bactericidal and fungicidal properties. Despite the numerous biological and pharmacological potentials, essential oils are unstable and have limited solubility in water, characteristics that can be improved by the formation of inclusion complexes with cyclodextrins (CDs). In the present study, the inclusion complex of CZEO and beta-CD was prepared by co-precipitation coupled to freeze drying and spray drying. The inclusion complex was characterized by vibrational spectroscopy (Raman spectroscopy and FT-IR) and the complexation efficiency determined by gas chromatography coupled to mass spectrometry (GC-MS). It was observed that coprecipitation coupled to lyophilization allowed greater complexation efficiencies when compared to the spray drying. Raman spectroscopy confirms the formation of the inclusion complex of beta-CD and CZEO by both preparation methods.