SPL Set ID: 3cd9a055-8b9b-4dff-967b-54023df72e43

Lidocaine and Prilocaine Cream, USP 2.5%/2.5% is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 1:1 by weight. This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals. It is packaged in 5 gram and 30 gram tubes. Lidocaine is chemically designated as acetamide, 2-(diethylamino)-N-(2,6-dimethylphenyl), has an octanol: water partition ratio of 43 at pH 7.4, and has the following structure: C 14 H 22 N 2 OM.W. 234.3 Prilocaine is chemically designated as propanamide, N-(2-methylphenyl)-2-(propylamino), has an octanol: water partition ratio of 25 at pH 7.4, and has the following structure: C 13 H 20 N 2 OM.W. 220.3 Each gram of Lidocaine and Prilocaine Cream, USP 2.5%/2.5% contains lidocaine 25 mg, prilocaine 25 mg, PEG-60 hydrogenated castor oil (as emulsifier), carbomer homopolymer Type B (as a thickening agent), sodium hydroxide to adjust to a pH approximating 9, and purified water to 1 gram. Lidocaine and Prilocaine Cream, USP 2.5%/2.5% contains no preservative, however it passes the USP antimicrobial effectiveness test due to the pH. The specific gravity of Lidocaine and Prilocaine Cream is 1.00.