This contract conducts analytical chemistry evaluation of drug substances and dosage formulations intended for use in animal efficacy models, toxicology studies, pharmaceutical dosage form manufacture, and clinical trials. It is used to develop and validate methods for detecting and quantitating experimental therapies (both chemical and biologic) in body fluids and tissues, and to conduct stability, identity, and purity studies of new drug formulations. Studies can be conducted in compliance with current FDA Good Laboratory Practice (GLP) regulations when necessary. This contract is part of a portfolio of contracts administered by the National Institute of Allergy and Infectious Diseases to facilitate the development of promising compounds for the prevention and treatment of infections caused by human immunodeficiency virus, AIDS-associated opportunistic pathogens, tuberculosis, and other infectious agents.