» Chlorpropamide Tablets contain not less than 90.0 percent and not more than 110.0 percent of the labeled amount of C10H13ClN2O3S.
Packaging and storage Preserve in well-closed containers.
USP Reference standards 11
Identification Shake a quantity of finely powdered Tablets, equivalent to about 100 mg of chlorpropamide, with 20 mL of 1 N hydrochloric acid, and extract with 50 mL of chloroform. Filter the chloroform through chloroform-washed cotton into a suitable beaker, and evaporate the chloroform on a steam bath with the aid of a current of dry air to dryness. Dry the residue at 105 for 1 hour: the residue so obtained responds to the Identification tests under Chlorpropamide.
Medium: water; 900 mL.
Apparatus 2: 50 rpm.
Time: 60 minutes.
Procedure Determine the amount of C10H13ClN2O3S dissolved from UV absorbances at the wavelength of maximum absorbance at about 230 nm of filtered portions of the solution under test, suitably diluted with 0.1 N hydrochloric acid in comparison with a Standard solution having a known concentration of USP Chlorpropamide RS in 0.1 N hydrochloric acid. [noteA volume of alcohol not exceeding 10% of the final volume of the Standard solution may be used to dissolve the USP Chlorpropamide RS. ]
Tolerances Not less than 75% (Q) of the labeled amount of C10H13ClN2O3S is dissolved in 60 minutes.
Uniformity of dosage units 905: meet the requirements.
Mobile phase , Standard preparation, and Chromatographic systemProceed as directed in the Assay under Chlorpropamide.
Assay preparation Weigh and finely powder not less than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 50 mg of chlorpropamide, to a 100-mL volumetric flask. Add Mobile phase to volume, mix, and filter, discarding the first 10 mL of the filtrate. Pipet 10 mL of the filtrate into a second 100-mL volumetric flask, add Mobile phase to volume, and mix.
Procedure Proceed as directed for Procedure in the Assay under Chlorpropamide. Calculate the quantity, in mg, of C10H13ClN2O3S in the portion of Tablets taken by the formula:
1000C(rU / rS)in which C is the concentration, in mg per mL, of USP Chlorpropamide RS in the Standard preparation; and rU and rS are the peak responses obtained from the Assay preparation and the Standard preparation, respectively.
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USP35NF30 Page 2646