SPL Set ID: 519a44e3-8a93-456c-b71c-894513810d45

Fosphenytoin Sodium Injection, USP is a prodrug intended for parenteral administration; its active metabolite is phenytoin. 1.5 mg of fosphenytoin sodium is equivalent to 1 mg phenytoin sodium, and is referred to as 1 mg phenytoin sodium equivalents (PE). The amount and concentration of fosphenytoin is always expressed in terms of mg PE. The pharmacological class of fosphenytoin sodium is hydantoin derivative, and the therapeutic class is anticonvulsant. Fosphenytoin sodium injection is marketed in 2 mL vials containing a total of 100 mg PE/2 mL (50 mg PE/mL) and 10 mL vials containing a total of 500 mg PE/10 mL (50 mg PE/mL), for intravenous or intramuscular administration. The concentration of each vial is 50 mg PE/mL. Fosphenytoin sodium injection is supplied in vials as a ready-mixed solution in Water for Injection, USP, and Tromethamine, USP (TRIS), buffer adjusted to pH 8.6 to 9.0 with either Hydrochloric Acid, NF, or Sodium Hydroxide, NF. Fosphenytoin sodium injection is a clear, colorless to pale yellow, sterile solution. The chemical name of fosphenytoin is 5,5-diphenyl-3-[(phosphonooxy)methyl]-2,4- imidazolidinedione disodium salt. The molecular structure of fosphenytoin is: The molecular weight of fosphenytoin is 406.24. structure