Lidocaine Ointment
» Lidocaine Ointment is Lidocaine in a suitable hydrophilic ointment base. It contains not less than 95.0 percent and not more than 105.0 percent of the labeled amount of lidocaine (C14H22N2O).
Packaging and storage— Preserve in tight containers.
USP Reference standards 11—
USP Lidocaine RS Click to View Structure
Identification— Stir a quantity of Ointment, equivalent to about 300 mg of lidocaine, with 20 mL of water, transfer to a separator, and extract with two 30-mL portions of solvent hexane. Wash the combined hexane extracts with 10 mL of water, 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 Identification test A under Lidocaine.
Microbial enumeration tests 61 and Tests for specified microorganisms 62— It meets the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa.
Minimum fill 755: meets the requirements.
Assay— Proceed with Ointment as directed in the Assay under Lidocaine Hydrochloride Jelly. Each mL of 0.01 N sulfuric acid is equivalent to 2.343 mg of C14H22N2O.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Mary S. Waddell
Scientific Liaison
1-301-816-8124		 (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 3682