A: The retention time of the major peak for chlorpheniramine maleate in the chromatogram of the Assay preparationcorresponds to that of the Standard preparation,as obtained in the Assay for chlorpheniramine maleate.

B: The retention time of the major peak for pseudoephedrine hydrochloride in the chromatogram of the Assay preparationcorresponds to that of the Standard preparationin the Assay for pseudoephedrine hydrochloride.

Add the following:

For Oral Solution Packaged In Single-Unit Containers: meets the requirements.USP28

Add the following:

For Oral Solution Packaged In Multiple-Unit Containers: meets the requirements.USP28

Mobile phase,System suitability solution,and Chromatographic system— Proceed as directed in the Assay for chlorpheniramine maleateunder Chlorpheniramine Maleate and Pseudoephedrine Hydrochloride Extended-Release Capsules.

Standard preparation— Dissolve an accurately weighed quantity of USP Chlorpheniramine Maleate RSin water to obtain a solution having a known concentration of about 1mg per mL.Transfer 1.0mLof this solution to a 100-mLvolumetric flask,add 80mLof Mobile phase,dilute with water to volume,and mix.

Assay preparation— Transfer an accurately measured volume of Oral Solution,equivalent to about 1mg of chlorpheniramine maleate,to a 100-mLvolumetric flask.Add about 80mLof Mobile phase,dilute with water to volume,mix,and filter.

Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the chlorpheniramine peaks.Calculate the quantity,in mg,of chlorpheniramine maleate (C16H19ClN2·C4H4O4)in the portion of Oral Solution taken by the formula: in which Cis the concentration,in mg per mL,of USP Chlorpheniramine Maleate RSin that Standard preparation;Vis the volume,in mL,of Oral Solution taken for the Assay preparation;and rUand rSare the chlorpheniramine peak responses obtained from the Assay preparationand the Standard preparation,respectively.

Mobile phase,System suitability solution,and Chromatographic system— Proceed as directed in the Assay for chlorpheniramine maleateunder Chlorpheniramine Maleate and Pseudoephedrine Hydrochloride Extended-Release Capsules.

Standard preparation— Dissolve an accurately weighed quantity of USP Pseudoephedrine Hydrochloride RSin water to obtain a solution having a known concentration of about 1.5mg per mL.Transfer about 1.0mLof this solution to a 10-mLvolumetric flask,add 8mLof Mobile phase,dilute with water to volume,and mix.

Assay preparation— Transfer an accurately measured volume of Oral Solution,equivalent to about 15mg of pseudoephedrine hydrochloride,to a 100-mLvolumetric flask.Add 80mLof Mobile phase,dilute with water to volume,mix,and filter.

Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the pseudoephedrine peaks.Calculate the quantity,in mg,of pseudoephedrine hydrochloride (C10H15NO·HCl)in the portion of Oral Solution taken by the formula: in which Cis the concentration,in mg per mL,of USP Pseudoephedrine Hydrochloride RSin the Standard preparation;Vis the volume,in mL,of Oral Solution taken for the Assay preparation;and rUand rSare the pseudoephedrine peak responses obtained from the Assay preparationand the Standard preparation,respectively.