Cephalexin Tablets for Oral Suspension
»Cephalexin Tablets for Oral Suspension contain not less than 90.0percent and not more than 110.0percent of the labeled amount of cephalexin (C12H15N3O2S).
Packaging and storage— Preserve in tight containers at controlled room temperature.
Identification— Mix a quantity of finely powdered Tablets for Oral Suspension with water to obtain a concentration of about 3mg of cephalexin per mL,and filter (Test solution).Proceed as directed in the Identificationtest under Cephalexin Capsules,beginning with “Place a suitable thin-layer chromatographic plate”:the RFvalue of the principal spot obtained from the Test solutioncorresponds to that obtained from the Standard solution.
Disintegration á701ñ— Tablets for Oral Suspension disintegrate in 3minutes,using water at 20±5.
Dissolution á711ñ—
Medium: water;900mL.
Apparatus 1: Use 40-mesh cloth and 100rpm.
Time: 30minutes.
Determine the amount of cephalexin (C12H15N3O2S)dissolved by employing the method specified in the Dissolutiontest under Cephalexin Tablets.
Tolerances— Not less than 80%(Q)of the labeled amount of cephalexin (C12H15N3O2S)is dissolved in 30minutes.
Dispersion fineness— Place 2Tablets for Oral Suspension in 100mLof water,and stir until completely dispersed.Asmooth dispersion is obtained that passes through a No.25sieve.
Uniformity of dosage units á905ñ: meet the requirements.
Water,Method Iá921ñ: not more than 9.0%.
Assay—
Mobile phase,Internal standard solution,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Cephalexin.
Assay preparation— Prepare a dispersion of not fewer than 20Tablets for Oral Suspension,accurately counted,using an accurately measured volume of water.Dilute an accurately measured portion of the dispersion quantitatively with water to obtain a solution containing about 1mg of cephalexin per mL.Pass a portion of the solution through a filter having a 1-µm or finer porosity.Transfer 10.0mLof the filtrate to a glass-stoppered conical flask,add 15.0mLof Internal standard solution,and mix.
Procedure— Proceed as directed for Procedurein the Assayunder Cephalexin.Calculate the quantity,in mg,of cephalexin (C12H15N3O2S)in each Tablet for Oral Suspension taken by the formula:
(L/D)(CP/1000)(RU/RS),
in which Lis the labeled quantity,in mg,of cephalexin in each Tablet for Oral Suspension;Dis the concentration,in mg per mL,of cephalexin in the filtrate used to prepare the Assay preparationon the basis of the number of Tablets for Oral Suspension taken,the labeled quantity of cephalexin in each Tablet,and the extent of dilution;and the other terms are as defined therein.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 416
Pharmacopeial Forum:Volume No.28(6)Page 1782
Phone Number:1-301-816-8335