Medium: water; 900 mL.

Apparatus 2: 50 rpm.

Time: 30 minutes.

Procedure— Determine the amount of anhydrous loracarbef (C16H16ClN3O4) dissolved from UV absorbances at the wavelength of maximum absorption at about 260 nm of filtered portions of the solution under test, suitably diluted with Dissolution Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Loracarbef RS in the same medium.

Tolerances— Not less than 75% (Q) of the labeled amount of anhydrous loracarbef (C16H16ClN3O4) is dissolved in 30 minutes.

Solution A, Solution B, Mobile phase, System suitability solution, Standard solution, and Chromatographic system— Proceed as directed in the test for Related compounds under Loracarbef.

Test solution— Remove, as completely as possible, the contents of not less than 5 Capsules. Weigh the contents, and determine the average weight of the content of each Capsule. Transfer an accurately weighed portion of the powder, equivalent to 125 mg of loracarbef, based on the labeled amount per Capsule, to a 25-mL volumetric flask. Add about 20 mL of Solution A to the flask, mix, sonicate, and mix on a vortex mixer to aid in dissolution. Dilute with Solution A to volume, and mix. Filter, and use the filtrate as the Test solution immediately, or refrigerate and use within 24 hours.

Procedure— Proceed as directed for Procedure in the test for Related compounds under Loracarbef, except to omit the injection of Phenylglycine solution. Calculate the percentage of each related compound in the portion of Capsule contents taken by the formula: in which C is the concentration, in mg per mL, of USP Loracarbef RS in the Standard solution; Y is the concentration, in mg per mL, of loracarbef in the Test solution; ri is the response of any related compound obtained from the Test solution; and rS is the loracarbef response obtained from the Standard solution: not more than 1.0% of any individual related compound is found, and the sum of all related compounds is not more than 3.0%.

Mobile phase, Standard preparation, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under Loracarbef.

Assay preparation— Remove, as completely as possible, the contents of not less than 20 Capsules. Transfer an accurately weighed portion of the powder, equivalent to about 10 mg of loracarbef, to a 50-mL volumetric flask. Add about 40 mL of Mobile phase, and dissolve with the aid of swirling and sonication. Dilute with Mobile phase to volume, and mix. Pass a portion of this solution through a filter having a porosity of 0.5 µm or finer, and use the filtrate as the Assay preparation.

Procedure— Proceed as directed for Procedure in the Assay under Loracarbef. Calculate the quantity, in mg, of loracarbef (C16H16ClN3O4) in the portion of Capsules taken by the formula: in which C is the concentration, in mg per mL, of USP Loracarbef RS in the Standard preparation; P is the specified potency, in µg of anhydrous loracarbef (C16H16ClN3O4) per mg, of USP Loracarbef RS; and rU and rS are the loracarbef peak responses obtained from the Assay preparation and the Standard preparation, respectively.