Packaging and storage—
Preserve in tight containers.
Identification—
Place a volume of Nasal Solution,equivalent to about 2.5mg of oxymetazoline hydrochloride,in a 60-mLseparator,and add water to make about 10mL.Add 2mLof sodium carbonate solution (1in 10),extract with 10mLof chloroform,and transfer the chloroform extract to a second 60-mLseparator.Extract the chloroform solution with 10mLof 0.1Nhydrochloric acid,allow to separate,and discard the chloroform layer.Transfer 8mLof the acidic aqueous layer to a test tube,neutralize by the dropwise addition of 1Nsodium hydroxide,add 1drop of 1Nsodium hydroxide in excess,and mix.Add a few drops of sodium nitroferricyanide TSand 2drops of sodium hydroxide solution (15in 100),mix,and allow to stand for 10minutes.Add 0.1Nhydrochloric acid dropwise until the pHis between 8and 9,and allow to stand for 10minutes:a violet color develops.
Assay—
Standard preparation—
Prepare a solution of
USP Oxymetazoline Hydrochloride RSin
Mobile phase,having a known concentration,approximately equal to the labeled concentration of the Nasal Solution.
Assay preparation—
Use Nasal Solution.
Chromatographic system
and
Procedure—Proceed as directed in the
Assayunder
Oxymetazoline Hydrochloride,except to calculate the quantity,in mg,of C
16H
24N
2O·HCl in each mLof the Nasal Solution taken by the formula:
C(rU/rS),
in which the terms are as defined therein.