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Identification,
Angular rotationá781Añ
Use
USP28the 0.1Nsulfuric acid extract of the chloroform solution obtained as directed for the
Assay preparation:
the angular rotation is levorotatory.
USP28
Assay
Standard preparation
Dissolve an accurately weighed quantity of
USP Ephedrine Sulfate RSin 0.1Nsulfuric acid to obtain a solution having a known concentration of about 20µg per mL.
Assay preparation
Transfer 5mLof Syrup to a separator,add 1mLof 1Nsulfuric acid,and extract with 10mLof chloroform.Discard the extract,and add 5mLof potassium carbonate solution (1in 5).After gas evolution has ceased,extract the solution with three 10-mLportions of chloroform,and combine the extracts in a second separator.Extract the chloroform solution with 50.0mLof 0.1Nsulfuric acid.Filter the acid layer through paper,and dilute 5.0mLof it with 0.1Nsulfuric acid to 100.0mL.
Procedure
Proceed as directed for
Procedurein the
Assayunder
Ephedrine Sulfate Capsules.Calculate the quantity,in mg,of (C
10H
15NO)
2·H
2SO
4in the portion of Syrup taken by the formula:
C(AU/AS),
in which
Cis the concentration,in µg per mL,of
USP Ephedrine Sulfate RSin the
Standard preparation;and
AUand
ASare the absorbances of the solutions from the
Assay preparationand the
Standard preparation,respectively.