Packaging and storage—
Preserve in single-dose or in multiple-dose containers, preferably of Type I glass.
Identification—
Mix a volume of Injection, equivalent to about 60 mg of hydralazine hydrochloride, with an amount of 1 N hydrochloric acid sufficient to prepare 25 mL of solution. Place 20 mL of this solution in a separator, wash with 10 mL of methylene chloride, and discard the methylene chloride washing. Mix the aqueous solution in the separator with 2 mL of sodium nitrite solution (14 in 1000), add 10 mL of methylene chloride, shake by mechanical means for 5 minutes, and allow the layers to separate. Pass the methylene chloride layer through a filter of anhydrous sodium sulfate that previously has been washed with methylene chloride, and collect the solution in a 50-mL beaker. Evaporate with the aid of gentle heat and a stream of dry nitrogen to dryness: the IR absorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima only at the same wavelengths as that of
USP Hydralazine Hydrochloride RS similarly treated and prepared.
Other requirements—
It meets the requirements under
Injections 
1
.
Assay—
Transfer to a 250-mL iodine flask an accurately measured volume of Injection, equivalent to about 100 mg of hydralazine hydrochloride. Add 20 mL of hydrochloric acid, cool to room temperature, add 5 mL of chloroform, and titrate with 0.02 M potassium iodate VS until the purple color of iodine disappears from the chloroform, adding the last portion of the potassium iodate solution dropwise and agitating the mixture vigorously and continuously. Each mL of 0.02 M potassium iodate is equivalent to 3.933 mg of hydralazine hydrochloride (C8H8N4·HCl).
