α-Mangostin/γ-Cyclodextrin Inclusion Complex: Formation and Thermodynamic Study

α-Mangostin (α-M) has various biological activities, such as anti-cancer, antibacterial, anti-fungal, anti-tyrosin, anti-tuberculosis, anti-inflammatory, and antioxidant. However, it has very low solubility in water. The formulation of this compound requires high amounts of solubilizers, which limits its clinical application. In addition, its low solubility in water is a barrier to the distribution of this drug, thus affecting its potency. Cyclodextrin (CD) is widely used as a solubility enhancer of poorly soluble drugs. This study aimed to increase the solubility of α-M in water through complex formation with CD. The complex of α-Mangostin and γ-Cyclodextrin (α-M/γ-CD CX) was prepared by the solubilization method, resulting in a solubility improvement of α-M in water. Characterization of α-M/γ-CD CX by using FTIR-Spectrometry, XRD, H-, C-, and HMBC-NMR showed that α-M was able to form an inclusion complex with γ-CD. The complex yielded an entrapment efficiency of 84.25 and the thermodynamic study showed that the α-M/γ-CD CX was formed spontaneously, based on the negative values of Gibbs energy and ΔH. Interestingly, the solubility of α-M/γ-CD CX significantly increased by 31.74-fold compared with α-M. These results suggest that α-M/γ-CD CX has the potential in the formulation of water-based preparation for clinical applications.