Cholestyramine for Oral Suspension
»Cholestyramine for Oral Suspension is a mixture of Cholestyramine Resin with suitable excipients and coloring and flavoring agents.It contains not less than 85.0percent and not more than 115.0percent of the labeled amount of dried cholestyramine resin.
Packaging and storage— Preserve in tight containers.
Identification— Transfer a quantity of Cholestyramine for Oral Suspension,equivalent to about 500mg of dried cholestyramine resin,to a suitable flask,add 100mLof 0.1Nhydrochloric acid,stir to suspend the solid,and heat on a steam bath for 10minutes.Filter,wash the residue with three 50-mLportions of water,and dry at 70and at a pressure not exceeding 50mm of mercury for 16hours:the IRabsorption spectrum of a potassium bromide dispersion of the residue so obtained exhibits maxima only at the same wavelengths as that of a similar preparation of USP Cholestyramine Resin RS.
Uniformity of dosage units á905ñ: meets the requirements forWeight Variation.
Assay—
Mobile phase,Potassium phosphate buffer,Sodium glycocholate solution,Reference solution,Standard solution,System suitability solution,and Chromatographic system— Proceed as directed in the test for Exchange capacityunder Cholestyramine Resin.
Test solution— Transfer an accurately weighed portion of Cholestyramine for Oral Suspension,equivalent to about 100mg of cholestyramine resin,to a 25-mLconical flask.Pipet 15.0mLof Sodium glycocholate solutioninto the flask,and stir by mechanical means for 2hours.Transfer the contents to a centrifuge tube,and centrifuge for 15minutes.Transfer 5.0mLof the supernatant to a 50-mLvolumetric flask,and dilute with water to volume.
Procedure— Separately inject equal volumes (about 50µL)of the Reference solution,the Standard solution,and the Test solutioninto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of cholestyramine resin per mg of Cholestyramine for Oral Suspension taken by the formula:
[M(2.5rR–rU)WS]/[(2.5rR–rS)WUQ],
in which Mis the stated value,in mg,of sodium glycocholate absorbed per g of USP Cholestyramine Resin RS;rR,rU,and rSare the peak responses obtained from the Reference solution,the Test solution,and the Standard solution,respectively;WSis the weight,in mg,of USP Cholestyramine Resin RStaken to prepare the Standard solution;WUis the weight,in mg,of Cholestyramine for Oral Suspension taken to prepare the Test solution;and Qis the quantity of sodium glycocholate absorbed per g of dried cholestyramine resin,as obtained in the test for Exchange capacityunder Cholestyramine Resin.
Auxiliary Information— Staff Liaison:Elena Gonikberg,Ph.D.,Scientist
Expert Committee:(PA4)Pharmaceutical Analysis 4
USP28–NF23Page 465
Pharmacopeial Forum:Volume No.28(1)Page 51
Phone Number:1-301-816-8251