for oral solution packaged in single-unit containers: meets the requirements.

for oral solution packaged in multiple-unit containers: meets the requirements.

Mobile phase— Dissolve 2.7 g of sodium acetate in 600 mL of water, add 400 mL of acetonitrile, and 4 mL of tetramethylammonium hydroxide solution in methanol (25%), and mix. Adjust with glacial acetic acid to a pH of 6.5, filter, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).

Standard stock solution— Dissolve an accurately weighed quantity of USP Metoclopramide Hydrochloride RS in 0.01 M phosphoric acid to obtain a stock solution having a known concentration of about 9 mg of anhydrous metoclopramide hydrochloride per mL.

System suitability solution— Transfer about 125 mg of benzenesulfonamide to a 25-mL volumetric flask, add 15 mL of methanol, and shake to dissolve. Dilute with 0.01 M phosphoric acid to volume, and mix. Pipet 15 mL of this solution and 5 mL of the Standard stock solution into a 250-mL volumetric flask, dilute with 0.01 M phosphoric acid to volume, and mix.

Standard preparation— Transfer 5.0 mL of the Standard stock solution to a 250-mL volumetric flask, dilute with 0.01 M phosphoric acid to volume, and mix to obtain a solution having a known concentration of about 180 µg of USP Metoclopramide Hydrochloride RS, on the anhydrous basis, per mL (equivalent to about 160 µg of anhydrous metoclopramide per mL).

Assay preparation— Transfer an accurately measured volume of Oral Solution, equivalent to about 4 mg of metoclopramide, to a 25-mL volumetric flask, dilute with 0.01 M phosphoric acid to volume, and mix.

Chromatographic system (see Chromatography 621)— Prepare as directed in the Assay under Metoclopramide Injection. The relative retention times are about 0.2 for benzenesulfonamide and 1.0 for metoclopramide.

Procedure— Separately inject equal volumes (about 20 µL) of the Standard preparation and the Assay preparation into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of metoclopramide (C14H22ClN3O2) in each mL of the Oral Solution taken by the formula: in which 299.80 and 336.26 are the molecular weights of metoclopramide and anhydrous metoclopramide hydrochloride, respectively; C is the concentration, in mg per mL, of USP Metoclopramide Hydrochloride RS, on the anhydrous basis, in the Standard preparation; V is the volume, in mL, of Oral Solution taken; and rU and rS are the peak responses of metoclopramide obtained from the Assay preparation and the Standard preparation, respectively.