FOR SOLID PACKAGED IN SINGLE-UNIT CONTAINERS: meets the requirements.

FOR SOLID PACKAGED IN SINGLE-UNIT CONTAINERS: between 9.0and 11.0,in the suspension constituted as directed in the labeling.

FOR SOLID PACKAGED IN MULTIPLE-UNIT CONTAINERS: between 8.5and 11.0,in the suspension constituted as directed in the labeling.

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

Solvent— Dissolve 2.2g of monobasic potassium phosphate in 1590mLof water,add 600mLof isopropyl alcohol,480mLof alcohol,and 330mLof acetonitrile,and mix.Adjust with 10Npotassium hydroxide to a pHof 8.4±0.1,and shake by mechanical means for 30minutes.

Assay preparation 1 (where packaged in a single-unit container)—Transfer the contents of a container of Azithromycin for Oral Suspension to a volumetric flask of such capacity,V,in mL,that when diluted to volume as directed in the following two sentences the solution will contain about 2mg of azithromycin per mL.Add a volume of Solventequal to about 70%of the volume of the flask,and shake by mechanical means for 30minutes.Dilute with Solventto volume,and mix.Transfer about 40mLof this suspension to a stoppered centrifuge tube,and centrifuge for about 20minutes.Transfer 2.0mLof the clear supernatant to a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Transfer 2.0mLof this solution to a second 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Assay preparation 2 (where packaged in a multiple-unit container)—Constitute Azithromycin for Oral Suspension as directed in the labeling.Transfer 5.0mLof the suspension so obtained,freshly mixed and free from air bubbles,to a volumetric flask of such capacity,Vm,in mL,that when diluted to volume as directed below,the solution will contain about 0.4mg of azithromycin per mL.Add a volume of Solventequal to about 70%of the volume of the flask,and shake by mechanical means for 30minutes.Dilute with Solventto volume,and mix.Transfer about 40mLof the suspension so obtained to a stoppered centrifuge tube,and centrifuge for about 20minutes.Transfer 5.0mLof the clear supernatant to a 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.Transfer 5.0mLof this solution to a second 50-mLvolumetric flask,dilute with Mobile phaseto volume,and mix.

Procedure— Proceed as directed for Procedurein the Assayunder Azithromycin.Calculate the quantity,in mg,of azithromycin (C38H72N2O12)in the single-unit container of Azithromycin for Oral Suspension taken by the formula: in which rUis the azithromycin peak response obtained from Assay preparation 1;and the terms C,P,rU,and rSare as defined therein.Calculate the quantity,in mg,of azithromycin (C38H72N2O12)in each 5mLof suspension taken from a container of Azithromycin for Oral Suspension where packaged in a multiple-unit container by the formula: in which rUis the azithromycin peak response obtained from Assay preparation 2;and the terms C,P,and rSare as defined therein.