Acetamide, 2-(diethylamino)-N-(2,6-dimethylphenyl)-, monohydrochloride, monohydrate.
2-(Diethylamino)-2¢,6¢-acetoxylidide monohydrochloride monohydrate [6108-05-0].
Anhydrous 270.80 [73-78-9].
» Lidocaine Hydrochloride contains not less than 97.5 percent and not more than 102.5 percent of C14H22 N2O·HCl, calculated on the anhydrous basis.
Packaging and storage Preserve in well-closed containers.
Labeling Where it is intended for use in preparing injectable dosage forms, the label states that it is sterile or must be subjected to further processing during the preparation of injectable dosage forms.
A: Dissolve about 300 mg in 5 to 10 mL of water in a separator, add 4 mL of 6 N ammonium hydroxide, and extract with four 15-mL portions of chloroform. Combine the chloroform extracts, evaporate with the aid of a current of warm air, and dry the residue in vacuum over silica gel for 24 hours: the crystalline precipitate so obtained responds to the Identification tests under Lidocaine.
B: Its solutions respond to the tests for Chloride 191.
Melting range 741: between 74 and 79, the preliminary drying treatment being omitted.
Water, Method I 921: between 5.0% and 7.0%.
Residue on ignition 281: not more than 0.1%.
Sulfate Dissolve about 200 mg in 20 mL of water, add 2 mL of 3 N hydrochloric acid, mix, and divide into two parts. To one part of the solution add 1 mL of barium chloride TS: no more turbidity is produced than is present in the remaining portion of the solution to which nothing has been added.
Heavy metals, Method I 231: 0.002%.
Other requirements Where the label states that Lidocaine Hydrochloride is sterile, it meets the requirements for Sterility Tests 71 and for Bacterial endotoxins under Lidocaine Hydrochloride Injection. Where the label states that Lidocaine Hydrochloride must be subjected to further processing during the preparation of injectable dosage forms, it meets the requirements for Bacterial endotoxins under Lidocaine Hydrochloride Injection.
Mobile phase Mix 50 mL of glacial acetic acid and 930 mL of water, and adjust with 1 N sodium hydroxide to a pH of 3.40. Mix about 4 volumes of this solution with 1 volume of acetonitrile, so that the retention time of lidocaine is about 4 to 6 minutes. Pass through a membrane filter having a 1-µm or finer porosity, and degas. Make adjustments if necessary (see System Suitability under Chromatography 621).
Standard preparation Dissolve about 85 mg of USP Lidocaine RS, accurately weighed, 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, and mix to obtain a Standard preparation having a known concentration of about 1.7 mg of lidocaine per mL.
Assay preparation Transfer about 100 mg of Lidocaine Hydrochloride, accurately weighed, to a 50-mL volumetric flask, dilute with Mobile phase to volume, and mix.
Resolution preparation Prepare a solution of methylparaben in Mobile phase containing about 220 µg per mL. Mix 2 mL of this solution and 20 mL of the Standard preparation.
Chromatographic system (see Chromatography 621) The liquid chromatograph is equipped with a 254-nm detector and a 3.9-mm × 30-cm column that contains packing L1. The flow rate is about 1.5 mL per minute. Chromatograph about 20 µL of the Resolution preparation, and record the peak responses as directed for Procedure: the resolution, R, between lidocaine and methylparaben is not less than 3.0. Chromatograph the Standard preparation, and record the peak responses as directed for Procedure: the relative standard deviation for replicate injections is not more than 1.5%.
Procedure Separately inject equal volumes (about 20 µL) of the Assay preparation and the Standard preparation into the chromatograph. Record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of C14H22N2O·HCl in the portion of Lidocaine Hydrochloride taken by the formula:
(270.80/234.34)(50C)(rU / rS)in which 270.80 and 234.34 are the molecular weights of lidocaine hydrochloride and lidocaine, respectively; C is the concentration, in mg per mL, of USP Lidocaine RS in the Standard preparation; and rU and rS are the lidocaine peak responses obtained from the Assay preparation and the Standard preparation, respectively.
Auxiliary Information Please check for your question in the FAQs before contacting USP.Chromatographic Column
USP32NF27 Page 2781Pharmacopeial Forum: Volume No. 31(2) Page 415
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.