ETHRANE (enflurane, USP), a nonflammable liquid administered by vaporizing, is a general inhalation anesthetic drug. It is 2-chloro-1,1,2-trifluoroethyl difluoromethyl ether (CHF₂OCF₂CHFCl). The boiling point is 56.5ºC at 760 mm Hg, and the vapor pressure (in mm Hg) is 175 at 20ºC, 218 at 25ºC, and 345 at 36ºC. Vapor pressures can be calculated using the equation:

The specific gravity (25º/25ºC) is 1.517. The refractive index at 20ºC is 1.3026-1.3030. The blood/gas coefficient is 1.91 at 37ºC and the oil/gas coefficient is 98.5 at 37ºC.

Enflurane is a clear, colorless, stable liquid whose purity exceeds 99.9% (area percent by gas chromatography). No stabilizers are added as these have been found, through controlled laboratory tests, to be unnecessary even in the presence of ultraviolet light. Enflurane is stable to strong base, does not decompose in contact with soda lime (at normal operating temperatures), and does not react with aluminum, tin, brass, iron or copper. The partition coefficients of enflurane at 25ºC are 74 in conductive rubber and 120 in polyvinyl chloride.

Last reviewed on RxList: 2/10/2010
This monograph has been modified to include the generic and brand name in many instances.