Hygroscopicity of lithium coordination polymers and their solid solutions

Coordination polymers (CPs) of active pharmaceutical ingredients (APIs) are relatively rare, though recent studies show how these forms can afford improved solubility and stability. Here, the hygroscopicity of two coordination polymers of lithium and their solid solutions is investigated. The two systems exhibit different behaviour, impacting their potential utility as drug substances. In particular, the solid solutions of {[(PRO)Li(MBNZ)_1−x(BNZ)_x]}_n (1_x) show lower stability than both the pure compounds whereas in the solid solutions of {[Li₂(SUC)_1−x(MAL)_x]}_n (2_x), the hygroscopicity varies more regularly with composition.