SPL Set ID: babdbce2-5cbd-4943-bc38-9ebdd696a77a

Acyclovir is a synthetic nucleoside analog active against herpes viruses. Acyclovir for Injection, USP is a sterile lyophilized powder for intravenous administration only. Each 500 mg vial contains 500 mg of acyclovir and 49 mg of sodium, and each 1,000 mg vial contains 1,000 mg acyclovir and 98 mg of sodium. Reconstitution of the 500 mg or 1,000 mg vials with 10 mL or 20 mL, respectively, of Sterile Water for Injection, USP results in a solution containing 50 mg/mL of acyclovir. The pH of the reconstituted solution is approximately 11. Further dilution in any appropriate intravenous solution must be performed before infusion (see DOSAGE AND ADMINISTRATION: Method of Preparation and Administration ). Acyclovir sodium is a white, crystalline powder with the molecular formula C 8 H 10 N 5 NaO 3 and a molecular weight of 247.19. The maximum solubility in water at 25°C exceeds 100 mg/mL. At physiologic pH, acyclovir sodium exists as the un-ionized form with a molecular weight of 225 and a maximum solubility in water at 37°C of 2.5 mg/mL. The pkas of acyclovir are 2.27 and 9.25. The chemical name of acyclovir sodium is 2-amino-1,9-dihydro-9-[(2-hydroxyethoxy)methyl]-6 H -purin-6-one monosodium salt; it has the following structural formula: chemical structure