Oxcarbazepine
(ox'' kar baz' e peen).
Click to View Image

C15H12N2O2 252.27
5H-Dibenz[b,f]azepine-5-carboxamide, 10,11-dihydro-10-oxo-;    
10,11-Dihydro-10-oxo-5H-dibenz[b,f]azepine-5-carboxamide     [28721-07-5].
DEFINITION
Oxcarbazepine contains NLT 98.0% and NMT 102.0% of C15H12N2O2, calculated on the anhydrous basis.
IDENTIFICATION
•  A. Infrared Absorption 197K [Note—If the spectrum obtained shows differences, dissolve the substance to be examined in chloroform, and evaporate to dryness. Compare the spectrum of the residue to that of a similarly prepared USP Oxcarbazepine RS. ]
•  B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
ASSAY
•  Procedure
Buffer:  6.8 g/L of monobasic potassium phosphate in water. For each L prepared add 2 mL of triethlyamine and mix. Adjust with phosphoric acid to a pH of 6.0 ± 0.1.
Mobile phase:  Methanol, acetonitrile, and Buffer (11:8:31)
Standard solution:  0.1 mg/mL of USP Oxcarbazepine RS in Mobile phase
Sample solution:  0.1 mg/mL of Oxcarbazepine in Mobile phase
Chromatographic system 
Mode:  LC
Detector:  UV 215 nm
Column:  4.6-mm × 25-cm; 5-µm packing L1
Column temperature:  50
Flow rate:  1.5 mL/min
Injection size:  10 µL
System suitability 
Sample:  Standard solution
Suitability requirements: 
Relative standard deviation:  NMT 2.0%
Analysis 
Samples:  Standard solution and Sample solution
Calculate the percentage of C15H12N2O2 in the portion of Oxcarbazepine taken:
Result = (rU/rS) × (CS/CU) × 100
rU== peak response from the Sample solution
rS== peak response from the Standard solution
CS== concentration of USP Oxcarbazepine RS in the Standard solution (mg/mL)
CU== concentration of Oxcarbazepine in the Sample solution (mg/mL)
Acceptance criteria:  98.0%–102.0% on the anhydrous basis
IMPURITIES
Inorganic Impurities 
•  Residue on Ignition 281: NMT 0.1%
SPECIFIC TESTS
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers. Store at controlled room temperature.
•  USP Reference Standards 11
USP Oxcarbazepine RS Click to View Structure
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Hariram Ramanathan, M.S.
Associate Scientific Liaison
1-301-816-8313
(SM42010) Monographs - Small Molecules 4
Reference Standards RS Technical Services
1-301-816-8129
rstech@usp.org
USP35–NF30 Page 4158
Pharmacopeial Forum: Volume No. 34(5) Page 1177