d-Xylose oxetane copolymers as bioderived and tuneable polyesters for amorphous solid dispersions

The ring-opening copolymerisation of cyclic anhydrides with an oxetane derived from natural monosaccharide d-xylose has been used to synthesise fully biobased water soluble polyesters, which are able to stabilise the amorphous phases of nifedipine and mefenamic acid, enhancing their apparent solubility in water up to 918 and 142% respectively. 2D picolitre-scale inkjet-printing, coupled with polarised optical microscopy (POM) analysis, enabled an initial, high-throughput miniaturised (ng-μg scale) screening of drug formulations. The best formulations were scaled up and analysed by FT-IR spectroscopy and DSC, revealing interactions between the drugs and polymers. Finally, drug dissolution studies demonstrated the effectiveness of the polymers in improving the drugs’ apparent solubility in water. These results showcase the potential of synthetic carbohydrate polymers as excipient for tailored drug formulations.