Excipients are components of a finished drug product other than the active pharmaceutical ingredient (API) and are added during formulation for a specific purpose. Although listed as inactive ingredients by FDA, excipients generally have well-defined functions in a drug product. As with active ingredients, they may be Small Molecule or complex and may vary in terms of degree of characterization. They may be chemically synthesized or may be either natural source or biotechnology-derived (recombinant). In contrast to active ingredients, minor components of an excipient may have significant impact on its pharmaceutical performance. Depending on the intended use, an excipient in a drug product may be an active ingredient in another drug product. The US Pharmacopeia–National Formulary (USP–NF) categorizes excipients as binders, disintegrants, diluents, lubricants, glidants, emulsifying–solubilizing agents, sweetening agents, coating agents, antimicrobial preservatives, and so forth. In addition to their functional performance, ideally, excipients should be chemically stable, nonreactive with the drug and other excipients, inert in the human body, have low equipment and ...