Carbamazepine Oral Suspension

» Carbamazepine Oral Suspension contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of carbamazepine (C15H12N2O).

Packaging and storage— Preserve in tight, light-resistant containers, protected from freezing and from excessive heat.

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USP Carbamazepine RS

Identification, Infrared Absorption

197S

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Solution— Place 5 mL of Oral Suspension in a separator containing 20 mL of 0.1 N sodium hydroxide, and extract with 25 mL of chloroform. Pass the extract through anhydrous sodium sulfate supported on filter paper into a beaker. Wash the anhydrous sodium sulfate with 10 mL of 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 10 mL of methylene chloride.

Microbial enumeration tests

and Tests for specified microorganisms

— The total bacterial count does not exceed 100 cfu per g, and the tests for Salmonella species and Escherichia coli are negative.

Uniformity of dosage units

905

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for oral suspension packaged in single-unit containers: meets the requirements.

Deliverable volume

698

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for oral suspension packaged in multiple-unit containers: meets the requirements.

Assay—

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

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

Procedure— Proceed as directed in the Assay under Carbamazepine. Calculate the quantity, in mg, of carbamazepine (C15H12N2O) in the portion of Oral Suspension taken by the formula:

10C(rU / rS)

in which the terms are as defined therein.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Ravi Ravichandran, Ph.D. Principal Scientific Liaison 1-301-816-8330	(SM42010) Monographs - Small Molecules 4
Reference Standards	RS Technical Services 1-301-816-8129 rstech@usp.org
61	Radhakrishna S Tirumalai, Ph.D. Principal Scientific Liaison 1-301-816-8339	(GCM2010) General Chapters - Microbiology
62	Radhakrishna S Tirumalai, Ph.D. Principal Scientific Liaison 1-301-816-8339	(GCM2010) General Chapters - Microbiology

USP35–NF30 Page 2482

Pharmacopeial Forum: Volume No. 29(6) Page 1857