Packaging and storage— Preserve in well-closed containers.

USP Reference standards á11ñ— USP Acetohexamide RS.

Identification— Evaporate on a steam bath to dryness a 20-mLportion of the diluted chloroform solution prepared as directed in the Assay:the residue meets the requirements of Identification testAunder Acetohexamide.

Dissolution á711ñ—

Uniformity of dosage units á905ñ: meet the requirements.

Assay— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 500mg of acetohexamide,to a 100-mLvolumetric flask,add 60mLof 0.1Nsodium hydroxide,and shake for 30minutes.Dilute with water to volume,mix,and filter,discarding the first 20mLof the filtrate.Transfer 20.0mLof the subsequent filtrate to a 125-mLseparator,add 2mLof 3Nhydrochloric acid,and extract with four 40-mLportions of chloroform,filtering each portion through chloroform-washed paper into a 200-mLvolumetric flask.Dilute with chloroform to volume,and mix.Transfer 20.0mLof this solution to a suitable beaker,and evaporate on a steam bath to dryness.Transfer the residue,with the aid of 0.1Nsodium hydroxide,to a 100-mLvolumetric flask,add 0.1Nsodium hydroxide to volume,and mix.Transfer 10.0mLof this solution to a third 100-mLvolumetric flask,dilute with water to volume,and mix.Concomitantly determine the absorbances of the solution from the Tablets and a Standard solution prepared from USP Acetohexamide RS,in the same medium,at a concentration of about 10µg per mL,in 1-cm cells,at the wavelength of maximum absorbance at about 247nm,with a suitable spectrophotometer,using 0.01Nsodium hydroxide as the blank.Calculate the quantity,in mg,of C15H20N2O4Sin the portion of Tablets taken by the formula: in whichCis the concentration,in µg per mL,of USP Acetohexamide RSin the Standard solution;and AUand ASare the absorbances of the solution from the Tablets and the Standard solution,respectively.

Expert Committee:(PA4)Pharmaceutical Analysis 4

USP28–NF23Page 44

Phone Number:1-301-816-8251