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.

Change to read:

Solution A, Solution B, and Mobile phase— Proceed as directed in the Assay.

System suitability solution— Dissolve accurately weighed quantities of USP Nabumetone RS and USP Nabumetone Related Compound A RS in acetonitrile to obtain a solution having known concentrations of about 1 mg per mL and 1 µg per mL, respectively.

Test solution— Use the Assay preparation.

Chromatographic system (see Chromatography 621)— Proceed as directed in the Assay, except to chromatograph the System suitability solution, and record the peak responses as directed for Procedure: the relative retention times are about 0.9 for nabumetone related compound A and 1.0 for nabumetone; the resolution, R, between nabumetone related compound A and nabumetone is not less than 1.5; the column efficiency is not less than 3600 theoretical plates; the tailing factor determined from the nabumetone peak is between 0.8 and 2.0; and the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Inject 10 µL of the Test solution into the chromatograph, record the chromatogram, and measure all of the peak areas. Calculate the percentage of each impurity in the portion of Nabumetone taken by the formula: in which F is the relative response factor for each impurity (see the accompanying table for values);USP29 ri is the peak response for each impurity; and rN is the nabumetone peak response. The limits of impurities are specified in the accompanying table. USP29

(Official January 1, 2007)

Solution A— Prepare a filtered and degassed mixture of water and glacial acetic acid (999:1).

Solution B— Prepare a filtered and degassed mixture of acetonitrile and tetrahydrofuran (7:3).

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).

Standard preparation— Dissolve an accurately weighed quantity of USP Nabumetone RS in acetonitrile to obtain a solution having a known concentration of about 1.0 mg per mL.

Assay preparation— Transfer about 100 mg of Nabumetone, accurately weighed, to a 100-mL volumetric flask, dissolve in and dilute with acetonitrile to volume, and mix.

Chromatographic system (see Chromatography 621)— The liquid chromatograph is equipped with a 254-nm detector and a 4.6-mm × 15-cm column that contains 4-µm packing L1. The flow rate is about 1.3 mL per minute. The chromatograph is programmed as follows. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 2.0%.

Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the nabumetone peaks. Calculate the quantity, in mg, of C15H16O2 in the portion of Nabumetone taken by the formula: in which C is the concentration, in mg per mL, of USP Nabumetone RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.