Identification—
The chromatogram of the
Assay preparationobtained as directed in the
Assayexhibits a major peak for azaperone,the retention time of which corresponds to that exhibited in the chromatogram of the
Standard preparation,obtained as directed in the
Assay.
Assay—
Mobile phase—
Prepare a filtered and degassed mixture containing 6volumes of acetonitrile and 4volumes of 0.01
Mdibasic potassium phosphate,and adjust by the addition of dilute phosphoric acid (1in 10)to a pHof 7.8±0.1.Make adjustments if necessary (see
System Suitabilityunder
Chromatography á621ñ).
Internal standard solution—
Prepare a solution of benzophenone in methanol containing about 0.5mg per mL.
Standard preparation—
Dissolve an accurately weighed quantity of
USP Azaperone RSin methanol,and dilute quantitatively with methanol to obtain a solution having a known concentration of about 0.5mg per mL.Combine 2.5mLof this solution with 2.5mLof
Internal standard solution,dilute quantitatively with methanol to 10.0mL,and mix.
Assay preparation—
Dilute an accurately measured volume of Injection quantitatively with methanol to obtain a solution containing about 0.5mg of azaperone per mL.Combine 2.5mLof this solution with 2.5mLof Internal standard solution,dilute quantitatively with methanol to 10.0mL,and mix.
Chromatographic system
(see
Chromatography á621ñ)—The liquid chromatograph is equipped with 243-nm detector and a 4.6-mm ×25-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph the
Standard preparation,and record the peak responses as directed for
Procedure:the resolution,
R,between the azaperone and internal standard peaks is not less than 2.7;and the relative standard deviation for replicate injections is not more than 2.0%.
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 azaperone (C
19H
22FN
3O)in each mLof the Injection taken by the formula:
(C)(L/D)(RU/RS),
in which
Cis the concentration,in mg per mL,of
USP Azaperone RSin the
Standard preparation;Lis the labeled quantity,in mg,of azaperone in each mLof the Injection;
Dis the concentration,in mg per mL,of azaperone in the
Assay preparation,based on the volume of Injection taken and the extent of dilution;and
RUand
RSare the ratios of the azaperone peak to the benzophenone peak obtained from the
Assay preparationand the
Standard preparation,respectively.