Procedure
Separately inject equal volumes (about 20 µL) of the
Standard preparation and the
Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C
18H
23NO
3 in each container of Dobutamine for Injection taken by the formula:
(301.39 / 337.84)(10CD)(rU / rS),
in which 301.39 and 337.84 are the molecular weights of dobutamine and dobutamine hydrochloride, respectively;
C is the concentration, in mg per mL, of
USP Dobutamine Hydrochloride RS in the
Standard preparation; D is the dilution factor in the
Assay preparation; and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.