A: Infrared Absorption 197K—

B: The retention time of the major peak in the chromatogram of the Assay preparation corresponds to that in the chromatogram of the Standard preparation, as obtained in the Assay.

for products labeled for dosing every 12 hours—

test 1—

test 2— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.

test 3— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.

test 5— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 5.

for products labeled for dosing every 24 hours—

test 6— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 6.

procedure for content uniformity—

Solution A, Solution B, Mobile phase, System suitability solution 1, System suitability solution 2, and Chromatographic system— Proceed as directed in the Assay.

Standard solution— Use the Standard preparation, prepared as directed in the Assay.

Test solution— Use the Assay preparation.

Procedure— Separately inject equal volumes (about 5 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the areas for the major peaks. Calculate the percentage of each impurity in the portion of Tablets taken by the formula: in which C is the concentration, in mg per mL, of bupropion hydrochloride in the Standard solution; F is the relative response factor for each impurity (see the accompanying table); D is the concentration, in mg per mL, of bupropion hydrochloride in the Test solution, based on the number of Tablets taken, the labeled quantity per Tablet, and the extent of dilution; ri is the peak response for each impurity obtained from the Test solution; and rS is the peak response for bupropion hydrochloride obtained from the Standard solution. See the accompanying table for limits of individual impurities based upon Tablet strength.

Solution A— Prepare a filtered and degassed mixture of water, acetonitrile, and trifluoroacetic acid (90:10:0.04).

Solution B— Prepare a filtered and degassed mixture of acetonitrile, water, and trifluoroacetic acid (95:5:0.03).

Mobile phase— Use variable mixtures of Solution A and Solution B as directed for Chromatographic system. Make adjustments if necessary (see System Suitability under Chromatography 621).

System suitability solution 1— Prepare separate solutions containing accurately weighed quantities of USP Bupropion Hydrochloride Related Compound C RS and USP Bupropion Hydrochloride Related Compound F RS in methanol to obtain solutions having concentrations of about 0.20 mg per mL. Transfer accurately measured volumes of these solutions to a suitable flask, and dilute with a mixture of 0.001 N hydrochloric acid and methanol (80:20) to obtain a solution having a concentration of about 0.0018 mg of USP Bupropion Hydrochloride Related Compound C RS per mL and 0.018 mg of USP Bupropion Hydrochloride Related Compound F RS per mL.

System suitability solution 2— Prepare a solution containing an accurately weighed quantity of m-chlorobenzoic acid to obtain a solution having a concentration of about 0.09 mg per mL. Dilute an accurately measured volume of this solution with a mixture of 0.001 N hydrochloric acid and methanol (80:20) to obtain a solution having a concentration of about 0.0018 mg of m-chlorobenzoic acid per mL.

Standard preparation— Dissolve an accurately weighed quantity of USP Bupropion Hydrochloride RS in a mixture of 0.001 N hydrochloric acid and methanol (80:20) to obtain a solution having a known concentration of about 0.6 mg of bupropion hydrochloride per mL.

Assay preparation— Transfer a number of Tablets to a suitable homogenizer vessel containing an accurately measured volume of methanol to obtain a concentration of about 3.0 mg of bupropion hydrochloride per mL. Immediately homogenize the sample for 30 seconds at 20,000 rpm. Allow to extract for 3 minutes, and follow by two additional 10-second pulses, each at 20,000 rpm, pausing 3 minutes between these pulses to ensure complete extraction. Pass a portion of the solution through a nylon filter having a 0.45-µm porosity, discarding the first 2 to 4 mL of the filtrate. Pipet 10.0 mL of the filtrate into a 50-mL volumetric flask, and add about 25 mL of 0.001 N hydrochloric acid. Allow to cool to room temperature, and dilute with 0.001 N hydrochloric acid to volume.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 226-nm detector and a 4.6-mm × 10-cm column that contains 3.5-µm packing L1. The flow rate is about 1.5 mL per minute. The chromatograph is programmed as follows. Chromatograph System suitability solution 1, System suitability solution 2, and the Standard preparation, and record the peak areas as directed for Procedure: the resolution, R, between bupropion hydrochloride related compound C and bupropion hydrochloride related compound F is not less than 1.5; the relative response factor for System suitability solution 2 is between 0.22 and 0.26 when calculated using the peak obtained in the Standard preparation; the tailing factor is not more than 1.9; and the relative standard deviation for replicate injections of the Standard preparation is not more than 1.5%.

Procedure— Separately inject equal volumes (about 5 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the areas for the major peaks. Calculate the amount, in mg, of bupropion hydrochloride (C13H18ClNO·HCl) in the portion of Tablets taken by the formula: in which T is the labeled quantity, in mg, of bupropion hydrochloride in the Tablet; C is the concentration, in mg per mL, of USP Bupropion Hydrochloride RS in the Standard preparation; D is the concentration, in mg per mL, of bupropion hydrochloride in the Assay preparation, based upon the labeled quantity per Tablet and the extent of dilution; and rU and rS are the peak responses for bupropion hydrochloride obtained from the Assay preparation and the Standard preparation, respectively.