Medical devices having local anesthetic effect and methods of their

Abstract

A compound with topical anesthetic and plasticizing properties is dissolved in polymeric material of a medical device. Extrusion, co-extrusion and coating techniques to form endotracheal tubes, drainage tubes and other medical devices with the topical anesthetic are disclosed. A hydrophobic anesthetic compound such as the base form of lidocaine is used which is more soluble in the polymeric wall material of the tube than in water. As a result, the anesthetic compound is transferred only to the contiguous tissue of the body passage and not disseminated systemically through the aqueous fluids. The anesthetic compound diffuses to the surface of body tissue touched by the tube where its anesthetic effect suppresses discomfort and undesired rejection reactions. Since the anesthetic compound is thus dispensed only to the contiguous tissue of the body passage, the quantity of anesthetic stored is sufficient to maintain effective anesthesia for hours or days, and undesired effects of a general dissemination through the body are avoided. Prilocaine base and dibucaine base are also used in examples. A water soluble form of topical anesthetic, achievable by reacting anesthetic base dissolved in the polymer, is provided, e.g. at an exposed surface, to enable rapid onset of anesthesia. Balloons, films and extruded cross sections are shown. Barrier and metering layers are shown to control the direction and rate of application of the anesthetic. Methods of introduction of the anesthetic into solution in the polymer are disclosed.