The landscape presented to those developing novel pharmaceutical agents for progression into a clinical environment is ever changing and continually challenging. One well-documented challenge is management of the poor physicochemical properties of many drug candidates emerging from discovery. The Biopharmaceutical Classification System (BCS) helps to define these challenges by presenting molecules within one of four categories that correlate solubility and permeability. A review of the approaches used to manipulate BCS Class II and IV candidates illustrates that salt formation is a common route traditionally employed to improve many fundamental properties of a molecule. For more information, please download our latest whitepaper.