A: 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.

B: Transfer an accurately weighed amount of Capsule contents,equivalent to about 10mg of diazepam,to a 50-mLcentrifuge tube,and add 2mLof acetone.Place the centrifuge tube in an ultrasonic bath for 5minutes,and centrifuge.Using 100µLof the supernatant as the test solution,and 100µLof a solution of USP Diazepam RSin acetone containing 5mg per mLas the Standard solution,proceed as directed for Identificationtest Bunder Diazepam.

Medium: 0.01Nhydrochloric acid;900mL.

Apparatus 1: 100rpm.

Time: 45minutes.

Procedure— Determine the amount of C16H13ClN2Odissolved by employing UVabsorption at the wavelength of maximum absorbance at about 284nm on filtered portions of the solution under test,suitably diluted with Dissolution Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Diazepam RSin the same Medium.

Tolerances— Not less than 85%(Q)of the labeled amount of C16H13ClN2Ois dissolved in 45minutes.

Mobile phase,System suitability solution,Standard preparation,andChromatographic system— Proceed as directed in the Assayunder Diazepam.

Assay preparation— Weigh and mix the contents of not less than 20Capsules.Transfer an accurately weighed portion of the capsule contents,equivalent to about 10mg of diazepam,to a 100-mLvolumetric flask.Add 50mLof methanol,sonicate for 5minutes,shake by mechanical means for 5minutes,dilute with methanol to volume,mix,and filter,discarding the first few mLof the filtrate.

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 major peaks.Calculate the quantity,in mg,of diazepam (C16H13ClN2O)in the portion of Capsules taken by the formula: in which Cis the concentration,in mg per mL,of USP Diazepam RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.