SPL Set ID: 58204dfe-f18d-41c4-80e4-eae54fe8d583

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 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: 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: 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 emulsifiers), carbomer homopolymer type B, 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 USP, 2.5%/2.5% is 1.00. Lidocaine Structure with formal and Mole wt Prilocaine with formula and mole weight