文摘
ASP3026(N-{2-Methoxy-4-[4-(4-methylpiperazin-1-yl)piperidin-1-yl]phenyl}-N鈥?[2-(propane-2-sulfonyl)phenyl]-1,3,5-triazine-2,4-diamine) was developed as a novel and selective inhibitor of the fusion protein EML4-ALK. Five polymorphs of ASP3026 (A01, A02, A03, A04, and A05) as well as a hydrate have been identified to date, and the most stable polymorph (A04) was selected for designing solid formulations. The influence of crystallization process parameters on nucleation of A03 and A04 was clarified for process development. A04 was obtained at relatively high temperatures and A03 at relatively low temperatures, regardless of the superaturation ratio. A03 and A04 were therefore able to be selectively obtained via temperature control, possibly due to temperature-dependent variations in the concentrations of conformers in solution. The relationship between polymorphs and solution structures before nucleation was investigated using in situ Raman spectroscopy. The relationship with the intensity ratios of nine Raman bands of both polymorphs and ASP3026 solution structures was investigated in detail. Our findings suggest that the solution structure shifted from a structure similar to that of A04 to one similar to that of A03 with decreasing temperature.