(lye' doe kane).
Lidocaine contains NLT 97.5% and NMT 102.5% of C14H22N2O.
• A. Infrared Absorption 197K: Previously dried in vacuum over silica gel for 24 h
• B. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.
Solution A: Water and glacial acetic acid (930:50). Adjust with 1 N sodium hydroxide to a pH of 3.40.
Mobile phase: Acetonitrile and Solution A (1:4), so that the retention time of lidocaine is 46 min
Standard solution: Dissolve 85 mg of USP Lidocaine RS, with warming if necessary, in 0.5 mL of 1 N hydrochloric acid in a 50-mL volumetric flask. Dilute with Mobile phase to volume.
System suitability stock solution: 220 µg/mL of methylparaben in Mobile phase
System suitability solution: Mix 2 mL of System suitability stock solution and 20 mL of Standard solution.
Sample solution: Dissolve 85 mg of Lidocaine, with warming if necessary, in 0.5 mL of 1 N hydrochloric acid in a 50-mL volumetric flask. Dilute with Mobile phase to volume.
Detector: UV 254 nm
Column: 3.9-mm × 30-cm; packing L1
Flow rate: 1.5 mL/min
Injection size: 20 µL
Samples: Standard solution and System suitability solution
Resolution: NLT 3.0 between lidocaine and methylparaben, System suitability solution
Relative standard deviation: NMT 1.5%, Standard solution
Samples: Standard solution and Sample solution
Calculate the percentage of C14H22N2O in the portion of Lidocaine taken:
Result = (rU/rS) × (CS/CU) × 100
Acceptance criteria: 97.5%102.5%
• Residue on Ignition 281: NMT 0.1%
• Chloride and Sulfate, Chloride 221: Dissolve 1.0 g in a mixture of 3 mL of 2 N nitric acid and 12 mL of water, and add 1 mL of silver nitrate TS: the turbidity does not exceed that produced by 50 µL of 0.020 N hydrochloric acid (0.0035%).
• Chloride and Sulfate, Sulfate 221: Dissolve 100 mg in a mixture of 1 mL of 2 N nitric acid and 10 mL of water. Filter if necessary, and add 1 mL of barium chloride TS. The turbidity does not exceed that produced by 0.10 mL of 0.020 N sulfuric acid (NMT 0.1%).
• Heavy Metals, Method I 231
Test preparation: 1.0 g
Analysis: Dissolve the Test preparation in a mixture of 2 mL of 3 N hydrochloric acid and 10 mL of water. Evaporate on a steam bath to dryness, and dissolve the residue in 25 mL of water.
Acceptance criteria: 20 ppm
• Melting Range or Temperature 741: 6669
• Packaging and Storage: Preserve in well-closed containers. Store at room temperature.
• USP Reference Standards 11
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USP35NF30 Page 3681Pharmacopeial Forum: Volume No. 36(5) Page 1191