Carbamazepine Tablets
» Carbamazepine Tablets contain not less than 92.0 percent and not more than 108.0 percent of the labeled amount of C15H12N2O.
Packaging and storage— Preserve in tight containers, preferably of glass. Dispense Carbamazepine Tablets in a container labeled “Store in a dry place. Protect from moisture.”
Labeling— The labeling indicates the Dissolution test with which the product complies.
USP Reference standards 11
USP Carbamazepine RS Click to View Structure
Identification— Boil, in a 50-mL beaker, a quantity of powdered Tablets, equivalent to about 250 mg of carbamazepine, with 15 mL of acetone for 5 minutes. Filter while hot into a second beaker, using two 5-mL portions of hot acetone to effect transfer. Evaporate with the aid of nitrogen to about 5 mL, and cool in an ice bath until crystals are formed. Filter the crystals, wash with 3 mL of cold acetone, and dry in vacuum at 70 for 30 minutes: the crystals so obtained respond to the Identification test under Carbamazepine.
Dissolution 711
for products labeled as 100-mg chewable tablets—
test 1— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 1.
Medium: water containing 1% sodium lauryl sulfate; 900 mL.
Apparatus 2: 75 rpm.
Time: 60 minutes.
Procedure— Determine the amount of C15H12N2O dissolved from UV absorbances at the wavelength of maximum absorbance at about 288 nm on filtered portions of the solution under test, suitably diluted with Medium, if necessary, in comparison with a Standard solution having a known concentration of USP Carbamazepine RS in the same Medium. [note—A volume of methanol not exceeding 1% of the final total volume of the Standard solution may be used to dissolve the carbamazepine. ]
Tolerances— Not less than 75% (Q) of the labeled amount of C15H12N2O is dissolved in 60 minutes. Use Acceptance Table 1, with the following exceptions: at S2, no unit is less than Q 5%; at S3, no unit is less than Q 10%; and not more than 2 of the 24 units are less than Q 5%.
for products labeled as 200-mg tablets—
test 2— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 2.
Medium , Apparatus, and Procedure—Proceed as directed for Test 1.
Times and Tolerances: between 45% and 75% of the labeled amount of C15H12N2O is dissolved in 15 minutes; not less than 75% (Q) of the labeled amount of C15H12N2O is dissolved in 60 minutes. Use Acceptance Table 2, with the following exceptions: at 15 minutes—at L2, no unit is more than 5% outside the stated range; at L3, no unit is more than 10% outside the stated range; and not more than 2 of the 24 units are more than 5% outside the stated range. At 60 minutes—at L2, no unit is less than Q 5%; at L3, no unit is less than Q 10%; and not more than 2 of the 24 units are less than Q 5%.
test 3— If the product complies with this test, the labeling indicates that it meets USP Dissolution Test 3.
Medium , Apparatus, and Procedure—Proceed as directed for Test 1.
Times and Tolerances: between 60% and 85% of the labeled amount of C15H12N2O is dissolved in 15 minutes; not less than 75% (Q) of the labeled amount of C15H12N2O is dissolved in 60 minutes. Use Acceptance Table 2, with the following exceptions: at 15 minutes—at L2, no unit is more than 5% outside the stated range; at L3, no unit is more than 10% outside the stated range; and not more than 2 of the 24 units are more than 5% outside the stated range. At 60 minutes—at L2, no unit is less than Q 5%; at L3, no unit is less than Q 10%; and not more than 2 of the 24 units are less than Q 5%.
Uniformity of dosage units 905: meet the requirements.
Water, Method III 921 Finely powder 20 Tablets, and accurately weigh about 1.5 g of the powder into a dry, tared evaporating dish. Dry at 120 for 2 hours: it loses not more than 5.0% of its weight.
Assay—
Mobile phase , System suitability solution, Standard preparation, and Chromatographic system—Proceed as directed in the Assay under Carbamazepine.
Assay preparation— Weigh and finely powder not fewer than 20 Tablets. Transfer an accurately weighed portion of the powder, equivalent to about 100 mg of carbamazepine, to a 50-mL volumetric flask, add about 40 mL of methanol, sonicate for about 15 minutes, allow to cool to room temperature, dilute with methanol to volume, mix, and filter, discarding the first 10 mL of the filtrate. Transfer 5.0 mL of this solution to a 50-mL volumetric flask, dilute with a mixture of methanol and water (1:1) to volume, and mix.
Procedure— Proceed as directed in the Assay under Carbamazepine. Calculate the quantity, in mg, of carbamazepine (C15H12N2O) in the portion of Tablets taken by the formula:
500C(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
711 Margareth R.C. Marques, Ph.D.
Senior Scientific Liaison
1-301-816-8106
(GCDF2010) General Chapters - Dosage Forms
USP35–NF30 Page 2483
Pharmacopeial Forum: Volume No. 31(4) Page 1044