Griseofulvin Tablets
»Griseofulvin Tablets contain not less than 90.0percent and not more than 115.0percent of the labeled amount of griseofulvin (C17H17ClO6).
Packaging and storage— Preserve in tight containers.
Labeling— The label indicates that the griseofulvin contained is known as griseofulvin (microsize).
Identification— The retention time of the major 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: water containing 40.0mg of sodium lauryl sulfate per mL;1000mL.
Apparatus 2: 75rpm.
Time: 90minutes.
Procedure— Determine the amount of C17H17ClO6dissolved from UVabsorbances at the wavelength of maximum absorbance at about 291nm of filtered portions of the solution under test,suitably diluted with a solution of methanol and water (4:1),if necessary,in comparison with a Standard solution having a known concentration of USP Griseofulvin RSin the same medium.
Tolerances— Not less than 75%(Q)of the labeled amount of C17H17ClO6is dissolved in 90minutes.
Uniformity of dosage units á905ñ: meet the requirements.
Procedure for content uniformity— Transfer 1Tablet to a suitable container,add an accurately measured volume of methanol sufficient to yield a concentration of griseofulvin not greater than 1mg per mL,shake by mechanical means for 1hour,or longer if necessary to disperse the specimen completely,and sonicate for 1minute.Centrifuge a portion of this solution,and quantitatively dilute an accurately measured volume of the clear supernatant to obtain a test solution containing about 10µg of griseofulvin per mL.Concomitantly determine the absorbances of the test solution and a Standard solution of USP Griseofulvin RSin methanol having a known concentration of about 10µg per mLat the wavelength of maximum absorbance at about 292nm,with a suitable spectrophotometer,using methanol as the blank.Calculate the quantity,in mg,of griseofulvin (C17H17ClO6)in the Tablet taken by the formula:
(CL/D)(AU/AS),
in which Cis the concentration,in µg per mL,of USP Griseofulvin RSin the Standard solution;Lis the labeled quantity,in mg,of griseofulvin in the Tablet;Dis the concentration,in µg per mL,of griseofulvin in the test solution,based on the labeled quantity per Tablet and the extent of dilution;and AUand ASare the absorbances of the test solution and the Standard solution,respectively.
Loss on drying á731ñ— Dry about 100mg of finely ground Tablets,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60for 3hours:it loses not more than 5.0%of its weight.
Assay—
Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in the Assayunder Griseofulvin.
Assay preparation— Weigh and finely powder not fewer than 20Tablets,and proceed as directed for Assay preparationin the Assayunder Griseofulvin Capsules,beginning with “transfer an accurately weighed portion.”
Procedure— Proceed as directed for Procedurein the Assayunder Griseofulvin.Calculate the quantity,in mg,of griseofulvin (C17H17ClO6)in the portion of Tablets taken by the formula:
PC(rU/rS),
in which Cis the concentration,in mg per mL,of USP Griseofulvin RSin the Standard preparation,and the other terms are as defined therein.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 921
Phone Number:1-301-816-8335