Amorphous solid dispersions in Poly(ε-caprolactone)/Xanthohumol bioactive blends: physicochemical and mechanical characterization.

Abstract

This paper reports the obtention of amorphous solid dispersions (ASDs) of Xanthohumol (XH) into PCL containing up to 50 wt% of the bioactive compound in amorphous form thanks to the advantageous specific interactions stablished in this system. The miscibility of the PCL/XH blends was investigated using DSC. The melting point depression analysis yielded a negative interaction parameter indicating the occurrence of favorable inter-association interactions. XRD analyses performed at room temperature agree with the crystallinity results obtained on the heating runs performed by DSC. FTIR spectroscopy reveals strong C=O···O-H specific interactions between the hydroxyl groups of XH and the carbonyl groups of PCL. The AFM analysis of the blends obtained by spin-coating shows the variation of crystalline morphology with composition. Finally, tensile tests reveal high toughness retention for the blends in which XH can be dispersed in amorphous form (containing up to 50 wt% XH). In summary, PCL is a convenient matrix to disperse XH in amorphous form, bringing the possibility to obtain completely amorphous bioactive materials suitable for the development of non-stiff biomedical devices.