Medium: 0.01Nhydrochloric acid;900mL.

Apparatus 2: 50rpm.

Time: 90minutes.

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 75%(Q)of the labeled amount of C13H21N3O·HCl is dissolved in 90minutes.

Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Prepare as directed in the Assayunder Procainamide Hydrochloride.

Assay preparation— Accurately weigh and mix the contents of 20Capsules.Transfer an accurately weighed portion of the mixture,equivalent to about 500mg of procainamide hydrochloride,to a 500-mLvolumetric flask.Add about 350mLof methanol to the flask,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,dilute with Mobile phaseto volume,and mix.[NOTE—Reserve the remainder of the clear supernatant for the Identification test.]

Procedure— Proceed as directed for Procedurein the Assayunder Procainamide Hydrochloride.Calculate the quantity,in mg,of C13H21N3O·HCl in the portion of Capsule contents taken by the formula: in which Cis the concentration,in mg per mL,of USP Procainamide Hydrochloride RSin the Standard preparation,and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.