Drug products administered by injection are characterized by three qualities possessed by no other type of pharmaceutical dosage form: sterility, freedom from pyrogenicity, and freedom from particulate matter. The achievement of sterile, non-pyrogenic, and particulate-free parenteral products provides a significant challenge to the ingenuity and creativity of parenteral scientists and technologists. When the term sterile appears on the label of a parenteral product, it means that the batch or lot from which the sample originated passed the requirements of the U.S. Pharmacopeia (USP) sterility test _71_ (or other national compendia sterility test requirement).