Medium: 0.1Nhydrochloric acid;900mL.

Apparatus 2: 50rpm.

Time: 60minutes.

Procedure— Determine the amount of C13H21N3O·HCl dissolved by employing UVabsorption at the wavelength of maximum absorbance at about 275nm on filtered portions of the solution under test,suitably diluted with an amount of 0.01Nsodium hydroxide that is not less than twice the volume of the portion of test solution taken,in comparison with a Standard solution having a known concentration of USP Procainamide Hydrochloride RSin the same media.

Tolerances— Not less than 80%(Q)of the labeled amount of C13H21N3O·HCl is dissolved in 60minutes.

Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Proceed as directed in theAssay underProcainamide Hydrochloride.

Assay preparation— Weigh and finely powder not less than 20Procainamide Hydrochloride Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 500mg of procainamide hydrochloride,to a 500-mLvolumetric flask,add about 350mLof methanol,and sonicate for 10minutes in a 40water bath.Allow the flask to cool to room temperature,dilute with methanol to volume,and mix.Centrifuge a portion of the suspension,transfer 5.0mLof the clear supernatant obtained to a 100-mLvolumetric flask,reserving the remainder of the clear supernatant for theIdentification test.Dilute withMobile phase to volume,and mix.

Procedure— Proceed as directed forProcedure in theAssay underProcainamide Hydrochloride.Calculate the quantity of C13H21N3O·HCl in the portion of Tablets taken by the formula: in whichCis the concentration,in mg per mL,of USP Procainamide Hydrochloride RSin theStandard preparation,and rUand rSare the procainamide peak responses obtained from theAssay preparation and theStandard preparation,respectively.