Medium— Dissolve 54.5g of glycine and 42.6g of sodium chloride in about 500mLof water in a 1000-mLvolumetric flask.Cautiously add,with swirling,14.2mLof hydrochloric acid,and allow to cool.Dilute with water to volume,and mix.Transfer 50mLof this stock solution to a flask,and dilute with water to 900mLto obtain a solution having a pHof 3.0±0.1.[NOTE—If necessary,adjust the pHof the stock solution with 10Nsodium hydroxide so that when 50mLis diluted with water to 900mLthe pHof the Dissolution Mediumis 3.0±0.1.]

Apparatus 2: 75rpm.

Time: 30minutes.

Procedure— Determine the amount of cefpodoxime (C15H17N5O6S2)dissolved by employing UVabsorption at about 259nm on filtered portions of the solution under test in comparison with a Standard solution having a known concentration of USP Cefpodoxime Proxetil RSprepared by dissolving an accurately weighed portion in a small volume of methanol and diluting quantitatively with Dissolution Medium.

Tolerances— Not less than 70%(Q)of the labeled amount of cefpodoxime (C15H17N5O6S2)is dissolved in 30minutes.

Mobile phase,Diluent,and Chromatographic system— Prepare as directed in the Assayunder Cefpodoxime Proxetil.

Standard preparation— Transfer about 30mg of USP Cefpodoxime Proxetil RS,accurately weighed,to a 50-mLvolumetric flask,dissolve in 5mLof methanol,dilute with Diluentto volume,and mix.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,dilute with Diluent to volume,and mix.Pass through a filter having a 0.45-µm or finer porosity.

Assay preparation— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 50mg of cefpodoxime to a 100-mLvolumetric flask.Dissolve in 40mLof Diluent,sonicating for 5minutes.Cool to room temperature,dilute withDiluent to volume,and mix.Transfer 5.0mLof this solution to a 100-mLvolumetric flask,dilute with Diluentto volume,mix,and pass through a filter having a 0.45-µm or finer porosity.

Procedure— Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparation into the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg of cefpodoxime (C15H17N5O6S2)in the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Cefpodoxime Proxetil RSin the Standard preparation;Pis the designated potency,in µg per mg,of cefpodoxime (C15H17N5O6S2)in USP Cefpodoxime Proxetil RS;and rUand rSare the sums of the peak responses for cefpodoxime proxetil S-epimer and cefpodoxime proxetil R-epimer obtained from the Assay preparationand the Standard preparation,respectively.