No abstract

No abstract

Three febuxostat-minoxidil salt solvates with acetone (ACE), tetrahydrofuran (THF) and isopropanol (IPA) are synthesized by solvent-assisted grinding and characterized by infrared (IR), nuclear magnetic resonance ( 1 H-NMR), single crystal and powder X-ray diffraction (PXRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). These febuxostat-minoxidil salt solvates feature isostructural with the same stoichiometries (1:1:1 molecule ratio). The proton transfers from the carboxylic group of febuxostat (FEB) to imino N atom of minoxidil (MIN), which forms the motif with combined R 2 2 (9) R 2 4 (8) R 2 2 (9) graph set in the three solvates. The solvents occupy the different positions related to the motif, which results in the apparent differences in PXRD patterns before/after desolvation although they are isostructures. The FEB-MIN·THF was more thermostable than FEB-MIN·ACE and FEB-MIN·IPA relative to solvent removal from DSC patterns, which is different from the results from the solvent-exchange experiments in chemical kinetics. All three salt solvates exhibit increased equilibrium solubility compared to FEB in aqueous medium.

Two azilsartan–piperazine salt solvates and a monohydrate feature crystal structural diversity and improve the azilsartan solubility over that of the free Az form. Az–Pz·EtOH and Az–Pz·H2O improve the plasma azilsartan concentration Cmax and AUC over the free Az form.

EE could form cocrystals with N-containing CCFs to attune the hygroscopicity and dissolution performance.