Nitroglycerin injection manufactured by a hospital pharmacy. A method used by a hospital pharmacy department for manufacturing and testing a ready-to-administer i.v. nitroglycerin injection is described, and costs for this extemporaneously prepared injection are compared with costs for commercially available nitroglycerin products for i.v. use. A powder adsorbate containing one part nitroglycerin and nine parts lactose was used to prepare nitroglycerin injection in two strengths: 0.04 mg/mL (250-mL quantities) in 0.9% sodium chloride injection and 0.4 mg/mL (400-mL quantities) in 5% dextrose injection. Each batch was tested for sterility, for presence of pyrogens (endotoxin testing), and for nitroglycerin concentration (spectrophotometric assay). In one year, a total of 1217 bottles of nitroglycerin injection were prepared. This required 75 hours; preparation from commercial i.v. nitroglycerin products would have required approximately 200 hours (including admixture preparation). First-year costs for extemporaneous preparation (excluding costs of i.v. solutions and containers) were approximately $2200, far less than drug costs alone for the commercial i.v. nitroglycerin products. Nitroglycerin injection of high quality and confirmed potency was prepared extemporaneously in a hospital pharmacy department. Costs for this method were substantially less than those for use of commercial i.v. nitroglycerin products.