Cephradine for Oral Suspension
»Cephradine for Oral Suspension is a dry mixture of Cephradine and one or more suitable buffers,colors,diluents,and flavors.It contains not less than 90.0percent and not more than 125.0percent of the labeled amount of cephradine,calculated as the sum of cephradine (C16H19N3O4S)and cephalexin (C16H17N3O4S).
Packaging and storage— Preserve in tight containers.
Identification— Constitute 1container of Cephradine for Oral Suspension as directed in the labeling.Mix a portion of the resulting suspension with water to obtain a concentration of about 3mg of cephradine per mL,and filter (test solution).Proceed as directed in the Identificationtest under Cephradine 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.
Uniformity of dosage units á905ñ—
FORSOLID PACKAGED IN SINGLE-UNIT CONTAINERS: meets the requirements.
Deliverable volume á698ñ: meets the requirements.
pHá791ñ: between 3.5and 6.0,in the suspension constituted as directed in the labeling.
Water,Method Iá921ñ: not more than 1.5%.
Assay—
Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Proceed as directed in the Assayunder Cephradine.
Assay preparation— Constitute Cephradine for Oral Suspension as directed in the labeling.Dilute an accurately measured volume of the suspension so obtained,freshly mixed and free from air bubbles,quantitatively with Mobile phaseto obtain a solution containing about 0.5mg of cephradine per mL.Filter a portion of this mixture through a filter having a porosity of 0.5µm or finer,discarding the first 5mLof the filtrate.Use the filtrate as the Assay preparation.
Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of cephradine (sum of cephradine and cephalexin)in each mLof constituted Oral Suspension taken by the formula:
(CP)(L/1000D)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Cephradine RSin the Standard preparation,Pis the designated potency,in µg per mg,of USP Cephradine RS,Lis the labeled quantity,in mg of cephradine,in each mLof the constituted Oral Suspension,Dis the concentration,in mg of cephradine per mL,of the Assay preparation,based on the labeled quantity of cephradine per mLof constituted Oral Suspension and the extent of dilution,and rUand rSare the sums of the cephradine and cephalexin peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 422
Phone Number:1-301-816-8335