Packaging and storage—
Preserve in tight containers.
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 limits 
61
—
It meets the requirements of the tests for absence of
Staphylococcus aureus and
Pseudomonas aeruginosa.
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.
meets the requirements.