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Tetrafluoroethane is a hydrofluorocarbon (HFC or HFA) aerosol propellant (containing hydrogen, fluorine and carbon), which is different from Freon CFC (containing chlorine, fluorine and carbon). The absence of chlorine and the presence of hydrogen in the molecule reduces the depletion of the ozone layer. Therefore, tetrafluoroethane can be used as an alternative to CFC in metered-dose inhalers. It also replaces CFC-12 as a refrigerant due to the same vapor pressure. Due to its very low kauri butanol value and solubility parameters, tetrafluoroethane is not a good solvent for surfactants in those metered dose inhalers (MDIs). Sorbitan trioleate, sorbitan sesquioleate, oleic acid and soybean lecithin have little solubility in tetrafluoroethane. Therefore, the actual amount of surfactant is not sufficient to adequately disperse the drug.
Tetrafluoroethane is a liquefied gas that is liquid in the package at room temperature and its own vapor pressure, or gaseous at room temperature and atmospheric pressure. Tetrafluoroethane liquid is usually colorless and odorless. Tetrafluoroethane gas has a slight ethereal odor at high concentration, and tetrafluoroethane is non-corrosive, non-irritating and non-flammable.
Tetrafluoroethane is stable. Liquefied gas is stable when used as a propellant and should be stored in a metal gas cylinder in a dry and cool place.
Tetrafluoroethane can be obtained in several different ways. Its preparation method is as follows:
1,1,2-Trichloro-1,2,2-trichloroethane (CFC-113) by isomerization/hydrofluorination to 1,1-dichloro-1,2,2,2-tetra Fluoroethane (CFC-114a) can be obtained by hydrogenation and dechlorination.
By trichloroethylene by 1-chloro-1,1,1-trichloroethane (HCFC-133a) in the hydrofluorination system.
Tetrafluoroethane is a hydrofluorocarbon (HFC or HFA) aerosol propellant (containing hydrogen, fluorine and carbon), which is different from Freon CFC (containing chlorine, fluorine and carbon). The absence of chlorine and the presence of hydrogen in the molecule reduces the depletion of the ozone layer. Therefore, tetrafluoroethane can be used as an alternative to CFC in metered-dose inhalers. It also replaces CFC-12 as a refrigerant due to the same vapor pressure. Due to its very low kauri butanol value and solubility parameters, tetrafluoroethane is not a good solvent for surfactants in those metered dose inhalers (MDIs). Sorbitan trioleate, sorbitan sesquioleate, oleic acid and soybean lecithin have little solubility in tetrafluoroethane. Therefore, the actual amount of surfactant is not sufficient to adequately disperse the drug.
Tetrafluoroethane is a liquefied gas that is liquid in the package at room temperature and its own vapor pressure, or gaseous at room temperature and atmospheric pressure. Tetrafluoroethane liquid is usually colorless and odorless. Tetrafluoroethane gas has a slight ethereal odor at high concentration, and tetrafluoroethane is non-corrosive, non-irritating and non-flammable.
Tetrafluoroethane is stable. Liquefied gas is stable when used as a propellant and should be stored in a metal gas cylinder in a dry and cool place.
Tetrafluoroethane can be obtained in several different ways. Its preparation method is as follows:
1,1,2-Trichloro-1,2,2-trichloroethane (CFC-113) by isomerization/hydrofluorination to 1,1-dichloro-1,2,2,2-tetra Fluoroethane (CFC-114a) can be obtained by hydrogenation and dechlorination.
By trichloroethylene by 1-chloro-1,1,1-trichloroethane (HCFC-133a) in the hydrofluorination system.
