The nurse is preparing to administer a prescription for cefazolin 600 mg IM every six hours. The available vial is labeled, "Cefazolin 1 gram," and the instructions for reconstitution state, "For IM use add 2 mL sterile water for injection. Total volume after reconstitution equals 2.5 mL." When reconstituted, how many milligrams are in each mL of solution? (Enter numeric value only.