The development of amorphous solid dispersions (ASD) is one way to overcome the bioavailability challenges of poorly water-soluble drug. Herein, Curcumin (CUR) was dispersed in the polymeric matrix of Eudragit®E100 by solvent evaporation, giving ASD, donated as CUR@Eudragit®E100. Solubility and stability of CUR were greatly enhanced. DSC and XRD analysis confirmed that the incorporated CUR was present in an amorphous state. The interaction between CUR and Eudragit®E100 was investigated through FTIR and molecular modelling studies which implied that -OH groups in CUR, and carboxyl and amino groups in Eudragit®E100 involved in the hydrogen bond formation. High resolution atomic force microscopy was employed to directly visualize the molecular morphology of Eudragit®E100 and CUR in CUR@Eudragit®E100 and the interaction between CUR and the polymer. pH influenced CUR release profile in which the sustained release pattern was revealed vs the physical mixtures. From the plasma concentration vs time profile graph, oral bioavailability of Cur@Eudragit®E100 was approximately 5-fold higher than that of native CUR. These results confirmed the potential of designing ASD to enhance the solubility and bioavailability of CUR, simultaneously deliver CUR through this alternative administration route.
Keywords: Curcumin; amorphous solid dispersions; bioavailability; high resolution atomic force microscopy; hydrogen bonding.