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
9H
13NO
2·HCl in each mL of the Nasal Solution taken by the formula:
100(C / V)(rU / rS),
in which
C is the concentration, in mg per mL, of
USP Phenylephrine Hydrochloride RS in the
Standard preparation, V is the volume, in mL, of Nasal Solution taken, and
rU and
rS are the peak responses obtained from the
Assay preparation and the
Standard preparation, respectively.