Cinoxacin Capsules
»Cinoxacin Capsules contain not less than 90.0percent and not more than 110.0percent of the labeled amount of C12H10N2O5.
Packaging and storage— Preserve in well-closed containers.
Identification— Using a portion of Capsule contents to prepare the Test preparation,proceed as directed in the test for Related compoundsunder Cinoxacin:the RFvalue of the principal spot obtained from the Test preparationcorresponds to that obtained from Solution A.
Dissolution á711ñ—
Medium: pH6.5phosphate buffer (see Buffer Solutionsin the section Reagents,Indicators,and Solutions);500mLfor Capsules containing 250mg or less of cinoxacin;1000mLfor Capsules containing more than 250mg of cinoxacin.
Apparatus 1: 100rpm.
Time: 30minutes.
Standard preparation— Dissolve an accurately weighed quantity of USP Cinoxacin RSin Dissolution Mediumto obtain a solution having a known concentration of about 0.35mg per mL.
Procedure— Determine the amount of C12H10N2O5dissolved from UVabsorbances at the wavelength of maximum absorbance at about 270nm of filtered portions of the solution under test,suitably diluted with 0.1Nsodium hydroxide,in comparison with the Standard preparation,similarly diluted.
Tolerances— Not less than 60%(Q)of the labeled amount of C12H10N2O5is dissolved in 30minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay— Transfer the contents of not less than 20Capsules to a suitable tared container,and weigh.Transfer an accurately weighed portion of the mixed powder,equivalent to about 250mg of cinoxacin,to a 100-mLvolumetric flask.Dilute with 0.1Msodium borate to volume,and mix.Filter the solution,discarding the first 20mLof the filtrate,transfer 2.0mLof the filtrate to a 500-mLvolumetric flask,dilute with water to volume,and mix.Concomitantly determine the absorbances of this solution and of a Standard solution of USP Cinoxacin RSin the same medium having a known concentration of about 10µg per mL,in 1-cm cells at the wavelength of maximum absorbance at about 352nm,using 2mLof 0.1Msodium borate diluted with water to 500mLas the blank.Calculate the quantity,in mg,of C12H10N2O5in the portion of Capsules taken by the formula:
25C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Cinoxacin RSin the Standard solution,and AUand ASare the absorbances of the solution from the Capsules and the Standard solution,respectively.
Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 475
Phone Number:1-301-816-8394