Solvates, Polymorphs, and Cocrystals

In solute-solution systems, often solvates occur as solid phases. In solvates, the solvent is part of the crystal structure, that is, coordinated in or accommodated by the crystal structure, thus representing a single phase. According to the differences in the crystal structure, solvates and the appropriate unsolvated solid exhibit different physicochemical properties such as melting point, solubility, dissolution behavior, processabflity, and stability. 

Cocrystals are intermediate compounds of (two or more) discrete neutral molecular species that are, in their pure forms, solids at ambient temperature. This distinguishes cocrystals from solvates where one of the constituents of the intermediate compound is a solvent that is liquid at ambient temperature. As 

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