Nafcillin Injection, USP is a frozen, iso-osmotic, sterile, nonpyrogenic premixed 50 mL or 100 mL solution containing 1 g or 2 g of nafcillin, respectively, added as Nafcillin Sodium, USP. Dextrose, USP has been added to the above dosages to adjust osmolality (approximately 1.8 g and 3.6 g as dextrose hydrous to the 1 g and 2 g dosages, respectively). Sodium Citrate Hydrous, USP has been added as a buffer (approximately 90 mg and 180 mg to the 1 g and 2 g dosages, respectively). The pH has been adjusted with hydrochloric acid and may have been adjusted with sodium hydroxide. The pH is 6.5 (6.0 to 8.5). The solution is intended for intravenous use after thawing to room temperature.