Patent ID: 8652443

Claim:
A method of locally anesthetizing the skin of a subject, comprising the step of applying topically to the skin of a subject in need thereof an effective amount of a composition comprising water, in a quantity from about 15% to about 40% by weight of the composition; propylene glycol, in a quantity from about 11% to about 18% by weight of the composition; lidocaine, in a quantity from about 1% to about 6% by weight of the composition; polysorbate 80, in a quantity from about 32% to about 39% by weight of the composition; 1,1,1,2-tetrafluoroethane, in a quantity from about 5% to about 13% by weight of the composition; benzalkonium chloride, in a quantity from about 0.008% to about 0.08% by weight of the composition; benzyl alcohol, in a quantity from about 0.8% to about 3.0% by weight of the composition; and isopropyl myristate, in a quantity from about 10% to about 35% by weight of the composition; wherein the water, the propylene glycol, the lidocaine, the polysorbate 80, the benzalkonium chloride, the benzyl alcohol, and the isopropyl myristate form a microemulsion; the microemulsion is optically clear and optically isotropic; the composition is a single phase; and the composition is optically clear.