Solution— Place 5mLof Oral Suspension in a separator containing 20mLof 0.1Nsodium hydroxide,and extract with 25mLof chloroform.Pass the extract through anhydrous sodium sulfate supported on filter paper into a beaker.Wash the anhydrous sodium sulfate with 10mLof chloroform,and add the washing to the extract.Evaporate the chloroform extract with the aid of a stream of nitrogen to dryness.Dissolve the residue in 10mLof methylene chloride.

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

FOR ORAL SUSPENSION PACKAGED IN MULTIPLE-UNIT CONTAINERS: meets the requirements.

Mobile phase,System suitability solution,Standard preparation,and Chromatographic system— Prepare as directed in the Assayunder Carbamazepine.

Assay preparation— Transfer an accurately measured volume of freshly mixed Oral Suspension,equivalent to about 200mg of carbamazepine,to a 100-mLvolumetric flask,add about 70mLof methanol,shake by mechanical means for about 30minutes,sonicate for about 2minutes,dilute with methanol to volume,and mix.Allow the solution to stand for about 10minutes,transfer 10.0mLof the clear solution to a 100-mLvolumetric flask,dilute with methanol to volume,and mix.This is the final Assay preparation.For system suitability determination,transfer 10.0mLof this solution to a suitable container,add 10.0mLof System suitability solution,and mix.

Procedure— Proceed as directed in the Assayunder Carbamazepine.Calculate the quantity,in mg,of carbamazepine (C15H12N2O)in the portion of Oral Suspension taken by the formula: in which the terms are as defined therein.