0.1M Sodium acetate buffer— Transfer 13.61g of sodium acetate trihydrate to a 1-liter volumetric flask,add water to dissolve,dilute with water to volume,and mix.Adjust with 0.1Macetic acid to a pHof 5.0.

Medium: 0.1M Sodium acetate buffer;900mL.

Apparatus 2: 50rpm.

Time: 30minutes.

Procedure— Determine the amount of clarithromycin (C38H69NO13)dissolved in the Dissolution Medium,as directed in the Assay,using instead of the Assay preparationa filtered portion of the solution under test diluted quantitatively with Mobile phaseto yield a test solution containing about 125µg of clarithromycin per mL.Calculate the quantity,in mg,of clarithromycin dissolved by the formula: in which Dis the appropriate dilution factor used to prepare the test solution and the other terms are as defined therein.

Tolerances— Not less than 80%(Q)of the labeled amount of clarithromycin (C38H69NO13)is dissolved in 30minutes.

Mobile phase,Standard preparation,Resolution solution,and Chromatographic system— Proceed as directed in the Assayunder Clarithromycin.

Assay preparation— Finely powder an accurately counted number of Tablets,equivalent to about 2000mg of clarithromycin,and with the aid of methanol quantitatively transfer the powder to a 500-mLvolumetric flask,add about 350mLof methanol,and shake by mechanical means for 30minutes.Dilute with methanol to volume,mix,and allow any insoluble matter to settle.Transfer 3.0mLof the supernatant to a 100-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Pass a portion of this solution through a filter having a porosity of 0.5µm or finer,and use the filtrate as the Assay preparation.

Procedure— Proceed as directed for Procedurein the Assayunder Clarithromycin.Calculate the quantity,in mg,of C38H69NO13in the portion of Tablets taken by the formula: in which Nis the number of Tablets taken,and the other terms are as defined therein.