Quinidine Sulfate Tablets
» Quinidine Sulfate Tablets contain amounts of quinidine sulfate and dihydroquinidine sulfate totaling not less than 90.0 percent and not more than 110.0 percent of the labeled amount of quinidine sulfate, calculated as (C20H24N2O2)2·H2SO4·2H2O.
Packaging and storage— Preserve in well-closed, light-resistant containers.
USP Reference standards 11
USP Quinidine Sulfate RS Click to View Structure
USP Quininone RS Click to View Structure
    C20H22N2O2     322.40
Identification— The Tablets meet the requirements of the tests for Identification under Quinidine Sulfate Capsules, powdered Tablets being used in place of the contents of Capsules.
Dissolution 711
Medium: 0.01 N hydrochloric acid; 900 mL.
Apparatus 1: 100 rpm.
Time: 30 minutes.
Procedure— Determine the amount of (C20H24N2O2)2·H2SO4·2H2O dissolved by employing UV absorption at the wavelength of maximum absorbance at about 248 nm on filtered portions of the solution under test, suitably diluted with Dissolution Medium, in comparison with a Standard solution having a known concentration of USP Quinidine Sulfate RS in the same Medium.
Tolerances— Not less than 85% (Q) of the labeled amount of (C20H24N2O2)2·H2SO4·2H2O is dissolved in 30 minutes.
Uniformity of dosage units 905: meet the requirements.
Procedure for content uniformity— Proceed as directed for Procedure for content uniformity in the test for Uniformity of dosage units under Quinidine Sulfate Capsules, using 1 powdered Tablet instead of the contents of 1 Capsule.
Chromatographic purity— Shake a quantity of powdered Tablets, equivalent to about 150 mg of quinidine sulfate, with 25 mL of diluted alcohol for 10 minutes, and filter. Using the filtrate as the Test preparation, proceed as directed in the test for Chromatographic purity under Quinidine Sulfate.
Assay— Proceed as directed in the Assay under Quinidine Sulfate Capsules, using powdered Tablets.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Sujatha Ramakrishna, Ph.D.
Senior Scientific Liaison
(SM22010) Monographs - Small Molecules 2
Reference Standards RS Technical Services
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
(GCDF2010) General Chapters - Dosage Forms
USP35–NF30 Page 4507