The currently available list of excipients in the market is unending. They include diverse classes of small molecules and macromolecules of natural or semi-synthetic origin, and they represent all states of matter—gases, liquids, semi-solids, and solids. Excipients are essential ingredients in drug products independent of the route of administration. New use(s) of an approved excipient or the development of novel excipients are driven by scientific and business decisions to address unmet medical need(s), including the essential need for excipients in drug products, patent protection, and revenues.