Medium: water; 900 mL.

Apparatus 2: 50 rpm.

Time: 30 minutes.

Procedure— Determine the amount of cefaclor dissolved by employing UV absorption at the wavelength of maximum absorbance at about 264 nm on filtered portions of the solution under test, suitably diluted with Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Cefaclor RS in the same Medium. Calculate the amount of cefaclor dissolved by the formula: in which AU and AS are the absorbances obtained from the solution under test and the Standard solution, respectively; CS is the concentration, in mg per mL, of the Standard solution; 900 is the volume, in mL, of Medium; 100 is the conversion factor to percentage; D is the dilution factor of the solution under test; and LC is the Tablet label claim, in mg.

Tolerances— Not less than 80% (Q) of the labeled amount of cefaclor is dissolved in 30 minutes.

Solvent, Blank solution, Solution A, Solution B, Mobile phase, Standard solution, System suitability solution, and Chromatographic system— Proceed as directed for Related compounds under Cefaclor.

Test solution— Weigh and finely powder not fewer than 20 Chewable Tablets. Transfer an accurately weighed portion of the composite, equivalent to about 50 mg of cefaclor, to a 10-mL volumetric flask. Dissolve in Solvent, using brief sonication, if necessary, to dissolve. Avoid heating. Dilute with Solvent to volume, mix, and filter. [note—Use this Test solution within 3 hours if stored at room temperature, or within 20 hours when stored under refrigeration.]

Procedure— Separately inject equal volumes (about 20 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the peak area responses for all the peaks. Calculate the quantity, in mg, of each related compound in the portion of Chewable Tablets taken by the formula: in which the terms are as defined for Related compounds under Cefaclor. Not more than 1.0% of any individual cefaclor related compound is found; and the sum of all cefaclor related compounds found is not more than 3.0%, not including the contribution of any peak that gives a result of less than 0.1%.

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

Assay preparation— Weigh and finely powder not fewer than 20 Chewable Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 75 mg of cefaclor, to a 250-mL volumetric flask, dilute with Mobile phase to volume, and mix. Sonicate, if necessary, to dissolve the cefaclor. Filter to obtain a clear solution.

Procedure— Proceed as directed in the Assay under Cefaclor. Calculate the quantity, in mg, of cefaclor (C15H14ClN3O4S) in the portion of Chewable Tablets taken by the formula: in which the terms are as defined therein.