C19H22FN3O 327.40

1-Butanone,1-(4-fluorophenyl)-4-[4-(2-pyridinyl)-1-piperazinyl]-.
4¢-Fluoro-4-[4-(2-pyridyl)-1-piperazinyl]butyrophenone [1649-18-9].

Packaging and storage— Preserve in well-closed containers,protected from light.Store at room temperature.

Labeling— Label it to indicate that it is for veterinary use only.

USP Reference standards á11ñ— USP Azaperone RS.

Identification,Infrared Absorption á197Kñ: previously dried.

Melting range á741ñ: between 92and 95.

Loss on drying á731ñ— Dry it in vacuum at 60for 4hours:it loses not more than 0.5%of its weight.

Residue on ignition á281ñ: not more than 0.1%.

Chromatographic purity— Dissolve an accurately weighed quantity of USP Azaperone RSin a mixture of acetone and methylene chloride (5:1)to obtain a solution having a concentration of 0.50mg per mL(Standard solution A).Quantitatively dilute a volume of Standard solution Awith the same solvent mixture to obtain a solution having a concentration of 0.25mg per mL(Standard solution B).Prepare a test solution by dissolving an accurately weighed quantity of Azaperone in a mixture of acetone and methylene chloride (5:1)to obtain a solution containing 50mg per mL.Separately apply 1µLeach of Standard solution A,Standard solution B,and the test solution to a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.2-mm layer of chromatographic silica gel mixture with chemically bonded amino groups,and allow the spots to dry.Develop the chromatograms in a solvent system consisting of a mixture of cyclohexane,acetone,and methanol (65:30:5)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chromatographic chamber,and allow the plate to air-dry.Examine the plate under short-wavelength UVlight,and compare the intensities of any secondary spots,other than any spot at the origin,observed in the chromatogram of the test solution with those of the principal spots in the chromatograms of Standard solution Aand Standard solution B:the sum of the intensities of the secondary spots obtained from the test solution corresponds to not more than the intensity of the principal spot in the chromatogram of Standard solution A(1.0%).

Assay— Dissolve about 120mg of Azaperone,accurately weighed,in 50mLof a mixture of methyl ethyl ketone and glacial acetic acid (7:1).Add 3drops of p-naphtholbenzein TS,and titrate with 0.1Nperchloric acid VS.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 16.37mg of C19H22FN3O.

Expert Committee:(VET)Veterinary Drugs

USP28–NF23Page 204

Phone Number:1-301-816-8178