Noninvasive dermal anesthetics

Abstract

An apparatus, product formulation, and method for improved dermal permeation of pharmaceuticals wherein the apparatus includes a thin drug formulation reservoir and a heat-generating chamber separated by a first non-permeable wall, wherein the reservoir and chamber are formed in or supported by a housing. The drug formulation reservoir houses or is capable of housing a predetermined amount of a formulation containing pharmaceutically-active agent(s). The heat-generating/temperature-regulating chamber includes a medium for generating controlled heat, preferably a chemical composition made of carbon, iron, water and/or salt which is activated upon contact with air (oxygen). The function of the heat-generating/temperature-regulating element is to heat the user's skin, rapidly bring the skin temperature to a desired and elevated narrow range and keep it in this range for sufficient time to obtain more rapid, enhanced and less variable dermal absorption of selected pharmaceutically-active agents and to obtain improved clinical effects. Structure for controlling the generation of heat is also disclosed. The apparatus may optionally include a spacing or standoff structure which spans the drug formulation reservoir between the non-permeable wall and the user's skin surface for maintaining a predetermined thickness of the drug formulation on the user's skin surface. Also, a novel product formulation which can be used with the apparatus which uses high percentage of eutectic mixture of local anesthetics to reduce the overall degradation rate of the local anesthetic compound(s) in formulations which are subject to hydrolysis.