Atenolol Tablets
»Atenolol Tablets contain not less than 90.0percent and not more than 110.0percent of the labeled amount of atenolol (C14H22N2O3).
Packaging and storage— Preserve in well-closed containers.
Identification—
A: Infrared Absorption á197Kñ—
Test specimen— Mix a quantity of powdered Tablets,equivalent to about 100mg of atenolol,with 15mLof methanol,heat the mixture to 50,and shake for 5minutes.Filter,and evaporate the filtrate on a water bath to dryness.Add 10mLof 0.1Nhydrochloric acid to the residue,warm the solution,shake,and filter.To the filtrate add sufficient 1Nsodium hydroxide to make it alkaline,extract the solution with 10mLof chloroform,drying the chloroform extract over anhydrous sodium sulfate.Filter the dried chloroform solution,evaporate the filtrate on a water bath to dryness,and dry the residue at 105for 1hour.
B: The retention time of the atenolol peak in the chromatogram of the Assay preparationcorresponds to that in the chromatogram of the Standard preparation,as obtained in the Assay.
Dissolution á711ñ—
Medium: 0.1Nacetate buffer,pH4.6,prepared by mixing 44.9parts (v/v)of 0.1Nsodium acetate with 55.1parts (v/v)of 0.1Nacetic acid solution;900mL.
Apparatus 2: 50rpm.
Time: 30minutes.
Determine the amount of C14H22N2O3dissolved by employing the following method.
Mobile phase andChromatographic system— Proceed as directed in the Assayunder Atenolol.
Standard solution— Quantitatively dissolve an accurately weighed quantity of USP Atenolol RSin Mobile phaseto obtain a solution having a known concentration of about 0.01mg per mL.
Test solution— Prepare a filtered portion of the solution under test.Quantitatively dilute an accurately measured volume of the filtrate with Mobile phaseto obtain a solution estimated to contain about 0.01mg of atenolol per mL.
Procedure— Proceed as directed in the Assay,except to inject the Test solutioninstead of the Assay preparation.Calculate the quantity,in mg,of C14H22N2O3dissolved by the formula:
900CD(rU/rS),
in which Cis the concentration,in mg per mL,of USP Atenolol RSin the Standard solution;Dis the dilution factor involved in preparing the Test solution;and rUand rSare the atenolol peak areas obtained from the Test solutionand the Standard solution,respectively.
Tolerances— Not less than 80%(Q)of the labeled amount of C14H22N2O3is dissolved in 30minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Assay—
Mobile phase,Standard preparation,andChromatographic system— Proceed as directed in the Assayunder Atenolol.
Assay preparation— Transfer 10Tablets to a 1000-mLvolumetric flask.Add 500mLof Mobile phase,and sonicate for about 15minutes to disintegrate the Tablets.Dilute with Mobile phaseto volume,and mix.Centrifuge a portion of this mixture,and dilute an accurately measured volume of the supernatant quantitatively with Mobile phaseto obtain a solution containing about 0.01mg of atenolol per mL.
Procedure— Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg of atenolol (C14H22N2O3)in each Tablet taken by the formula:
C(L/D)(rU/rS),
in which Cis the concentration,in mg per mL,of USP Atenolol RSin the Standard preparation;Lis the labeled quantity,in mg,of atenolol in each Tablet;Dis the concentration,in mg per mL,of atenolol in the Assay preparation,based on the labeled quantity per Tablet and the extent of dilution;and rUand rSare the peak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 194
Pharmacopeial Forum:Volume No.29(1)Page 49
Phone Number:1-301-816-8305