Rationalization of the formation and stability of bosutinib solvated forms

Abstract

Crystallization of bosutinib from a wide variety of solvents resulted in many distinct structures, and displayed difficulties to crystallize without solvent incorporation. We have prepared 23 solvated/hydrated and one anhydrous solid form and for 11 of them solved the crystal structures. With the goal of rationalizing the high propensity to solvate formation and exploring the stability relationships between the phases, the solid forms were characterized by different experimental and computational methods. Their stability was compared theoretically by calculating the packing efficiency in the crystal structures and the binding energy of the solvent in the crystal lattice using differential scanning calorimetry. Experimental studies were completed by analysing the forms' physical stability in solid state and in suspension and their intrinsic dissolution rate. The survey conducted on the inclusion compounds has resulted in basic understanding of the underlying factors affecting discriminative solvate formation: the solvents are utilised to satisfy previously unused hydrogen bonding capabilities in the host molecule.