Isoproterenol Sulfate
(C11H17NO3)2·H2SO4·2H2O 556.63

1,2-Benzenediol,4-[1-hydroxy-2-[(1-methylethyl)amino]ethyl]-,sulfate (2:1)(salt),dihydrate.
3,4-Dihydroxy-a-[(isopropylamino)methyl]benzyl alcohol sulfate (2:1)(salt)dihydrate [6700-39-6].

Anhydrous 520.60 [299-95-6].
»Isoproterenol Sulfate contains not less than 97.0percent and not more than 103.0percent of (C11H17NO3)2·H2SO4,calculated on the anhydrous basis.
Packaging and storage— Preserve in tight,light-resistant containers.
Identification—
A: Ultraviolet Absorption á197Uñ—
Solution: 50µg per mL.
Medium: 0.1Nhydrochloric acid.
B: To a solution of 10mg in 5mLof water add 1drop of ferric chloride TS:an intense green color is produced,and it becomes olive-green on standing.
C: To a solution of 10mg in 1mLof water add 1drop of phosphotungstic acid TS:a white precipitate is formed immediately and it becomes brown on standing (distinction from epinephrine,which forms no precipitate).
D: Dilute 1.0mLof a solution (1in 1000)with water to 10mL,add 0.1mLof dilute hydrochloric acid (1in 120),then add 1.0mLof 0.10Niodine.Allow to stand for 5minutes,and add 2.0mLof 0.10Nsodium thiosulfate:a salmon pink color is produced (distinction from norepinephrine,which,at the same pH,about 3,produces no color or at most only a slight pink color).
E: It responds to the tests for Sulfate á191ñ.
Water,Method Iá921ñ: not more than 7.0%.
Residue on ignition á281ñ: not more than 0.2%.
Chloride á221ñ— A0.10-g portion shows no more chloride than corresponds to 0.20mLof 0.020Nhydrochloric acid (0.14%).
Limit of isoproterenone— It meets the requirements of the test for Isoproterenoneunder Isoproterenol Hydrochloride.
Organic volatile impurities,Method Iá467ñ: meets the requirements.
Assay—
Standard preparation— Prepare as directed in the Assayunder Isoproterenol Hydrochloride.
Assay preparation— Transfer about 125mg of Isoproterenol Sulfate,accurately weighed,to a 25-mLvolumetric flask,dissolve in sodium bisulfite solution (3in 1000),dilute with sodium bisulfite solution to volume,and mix.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,dilute with 0.17Nacetic acid to volume,and mix.
Chromatographic system— Proceed as directed for Procedurein the Assayunder Isoproterenol Hydrochloride.Calculate the quantity,in mg,of (C11H17NO3)2·H2SO4in the portion of Isoproterenol Sulfate taken by the formula:
(260.30/247.72)(0.5C)(hU/hS),
in which 260.30is one-half of the molecular weight of anhydrous isoproterenol sulfate,247.72is the molecular weight of isoproterenol hydrochloride,and C,hU,and hSare as defined therein.
Auxiliary Information— Staff Liaison:Kahkashan Zaidi,Ph.D.,Senior Scientific Associate
Expert Committee:(AER)Aerosols
USP28–NF23Page 1082
Phone Number:1-301-816-8269