A: The contents of the Capsules meet the requirements under Identification—Organic Nitrogenous Bases á181ñ.

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

Medium: water;500mL.

Apparatus 1: 100rpm.

Time: 30minutes.

Mobile phase and Chromatographic system—Prepare as directed in the Assay.

Procedure— Inject a measured volume (about 50µL)of a filtered portion of the solution under test into the chromatograph,record the chromatogram,and measure the response for the major peak.Determine the quantity of C17H21NO·HCl dissolved in comparison with a Standard solution having a known concentration of USP Diphenhydramine Hydrochloride RSin the same medium and similarly chromatographed.

Tolerances— Not less than 80%(Q)of the labeled amount of C17H21NO·HCl is dissolved in 30minutes.

Mobile phase, Standard preparation,System suitability solution,and Chromatographic system—Prepare as directed in the Assayunder Diphenhydramine Hydrochloride.

Assay preparation— Weigh and combine the contents of not fewer than 20Capsules.Transfer an accurately weighed portion of the combined Capsule contents,equivalent to about 50mg of diphenhydramine hydrochloride,to a 100-mLvolumetric flask.Dissolve in and dilute with water to volume,mix,and filter.

Procedure— Proceed as directed for Procedurein the Assayunder Diphenhydramine Hydrochloride.Calculate the quantity,in mg,of C17H21NO·HCl in the portion of Capsule contents taken by the formula: in which Cis the concentration,in mg per mL,of USP Diphenhydramine Hydrochloride RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.