Parameters affecting solubility: Crystal characteristics: Polymorphism:Polimorphs are different crystalline forms of the same substance.Each form has a different crystalline lattice and different lattice enthalpies.This results in different dissolution enthalpies(Hsol).As a general rule,the less stable polimorphs have higher aqueous solubilities and hence faster dissolution rate. Amorphous:Amorphous forms(without crystalline structure)are usually more soluble compared with the crystalline form of the same substance. Solvates:Crystalline forms that include solvent molecules into the crystalline lattice.Generally the solvate has lower solubility and dissolution rate into the solvating solvent