Methenamine Mandelate Tablets
»Methenamine Mandelate Tablets contain not less than 95.0percent and not more than 105.0percent of the labeled amount of methenamine mandelate (C6H12N4·C8H8O3).
Packaging and storage— Preserve in well-closed containers.
Identification,Infrared Absorption á197ñ Obtain the test specimen as follows.Triturate a quantity of finely powdered Tablets,equivalent to about 5.0mg of methenamine mandelate,with 5mLof chloroform,and pass through a 0.45-µm membrane filter.Evaporate the solvent,and allow the residue to air-dry.
Dissolution á711ñ
FOR UNCOATED OR PLAIN COATED TABLETS
Medium: water;900mL.
Apparatus 1: 100rpm.
Time: 45minutes.
Procedure— Determine the amount of C6H12N4·C8H8O3dissolved from UVabsorbances at the wavelength of maximum absorbance at about 257nm of portions of the solution under test,filtered through a 0.45-µm filter and suitably diluted with Medium,if necessary,in comparison with a Standard solution having a known concentration of USP Methenamine Mandelate RSin the same Medium.
Tolerances— Not less than 75%(Q)of the labeled amount of C6H12N4·C8H8O3is dissolved in 45minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay— Weigh and finely powder not fewer than 20Tablets.Weigh accurately a portion of the powder,equivalent to about 60mg of methenamine mandelate,and transfer to a 250-mLconical flask.Proceed as directed in the Assayunder Methenamine Mandelate,beginning with “Add 15mLof dehydrated alcohol.”
Auxiliary Information— Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1244
Phone Number:1-301-816-8394