Freon propellants

DPIs do not utilize Freon propellants, but use either with or without lactose as vehiculum. These devices have a clinical efficacy similar to standard metered-dose inhalers, but may be easier to use in selected patients, since a minimal inspiratory flow rate is necessary to inhale from a DPI. Therefore, the DPI may be difficult for patients with an insufficient inspiratory flow rate, which occurs in children, the elderly, people with severe COPD shared with diaphragm dysfunction, and during an exacerbation. The inspiratory flow rate is associated with the internal resistance of the device used. For instance the turbuhalor has a significant internal resistance and its delivered dose is dependent from the inspiratory flow rate. 

The Arrow implantable pump is non-programmable and delivers infusate (2-deoxy-5-fluorouridine, morphine sulfate, baclofen, or heparinized saline) at 3 pre-set flow rates. The pump is divided into two chambers by accordion-like movable bellows. Infusate is placed in the inner dmg reservoir chamber and Freon propellant in the outer chamber (Figure 4.19). 

Drug delivery from this pump is powered by the Freon propellant. When the Arrow pump is implanted subcutaneously, it is warmed by the patient s body temperature so that the propellant-containing chamber expands and exerts pressure on the movable bellows. Infusate is thus forced out of the reservoir chamber to an attached catheter through a filter and flow restrictor. This mechanism allows the delivery of infusate at a fairly constant rate to surrounding tissues or blood vessels. It should be noted, however, that the vapour pressure exerted by the outer chamber can be affected by changes in altitude/elevation or body temperature. 

Beclomethasone dipropionate is the 9-chloro-analogue of betamethasone dipropionate. It was developed by Glaxo and introduced in the United States by Schering Corp. for topical use in the treatment of asthma and allergic rhinitis by the inhalation of a freon-propelled aerosol. 

The main uses of halogenatcd methanes are as refrigerants (Freons), propellants. dry cleaning solvents, in Teflon manufacture, narcotics, and fire extinguishing systems. 

The modern pressurized metered dose inhaler (pMDI) was developed between 1955 and 1956. However, the pMDI had its roots in research carried out many years before.During the 1930s and 1940s, the discovery of liquefied propellants (chlorinated-fluorocarbons or freon propellants) such as CFC12, CFC114, CFCll, and CFC22 was a major step in the realization of a portable inhaler. However, the first pMDI was not invented until 1956, when the metering valve used in the device was developed and patented. ... 

Leach, C.L. Approaches and challenges to use freon propellant replacements. Aerosol Sci. Technol. 1995, 22, 328-334. 

Mace is a liquid mixture containing CN (active ingredient), hydrocarbons, and freon propellant in 1,1,1 -trichloroethane. 

The pressurized metered-dose inhaler (pMDI) for the delivery of antiasthma drugs originated in the U.S. cosmetic industry. George Maison, the president of Riker Laboratories, and Irvin Porash, who worked in Riker s pharmaceutical development laboratory, are credited with the development of the first pMDI (32). Experiments were conducted to formulate pressurized aerosols of isoproterenol and epinephrine, which had been dissolved in alcohol, using the freon propellants 12 and 114. 

Some of the chemicals frequently used in huffing along with their common sources given in parentheses are as follows acetone (solvent—paint or hardware store), butane (disposable cigar and cigarette lighters), propane (outdoor grill fuel, spray paint propellent), toluene (solvent—paint or hardware store), methylene chloride (paint stripper— paint or hardware store). Freon (propellent—compressed gas duster), and xylene (solvent—paint or hardware store). 

C. Manufactured by the action of HF on CCI4 using SbClj as a catalyst. Known commercially as Freon-12 or Arcton-12. Widely used as a refrigerant and aerosol propellant. It is much less toxic than carbon tetrachloride. 

Dicblorodifluoromethane (Freon 12) 175-71-8] M 120.9, m -158", b -29.8"/atm, 42.5"/10atm. Passage through saturated aqueous KOH then cone H2SO4, and a tower packed with activated copper on Kielselguhr at 200° removed CO2 and O2. A trap cooled to -29° removed a trace of high boiling material. It is a non-flammable propellant. 

The catalyst is formed by reaction of HF on SbClj. The Freons have a unique combination of properties which make them ideally suited for use as refrigerants and aerosol propellants. They have low bp, low viscosity, low surface tension and high density, and are non-toxic, non-flammable, odourless, chemically inert and thermally stable. The most commonly used is CF2CI2, bp, —29.8°. The market for Freons... 

Many gases dissolve in fats and make good propellants. However, most are flammable or toxic, or they react with the fats. Other possible propellants, such as the propane used in hairsprays or in Freon, also cause intoxication when they dissolve in the fats around nerve cells. These substances are not used, since their flammability, safety, cost, or taste makes them less desirable than nitrous oxide for spray cans of whipping cream. 

C05-0071. Freons (CFCs) are compounds that contain carbon, chlorine, and fluorine in various proportions. They are used as foaming agents, propellants, and refrigeration fluids. Freons are controversial because of the damage they do to the ozone layer in the stratosphere. A 2.55-g sample of a particular Freon in a 1.50-L bulb at 25.0 °C has a pressure of 262 torr. What is the molar mass and formula of the compound ... 

Freons have been used as refrigerants, solvents, and propellants in aerosol cans. 

Synonyms AI3-01708 Algofrene type 2 Arcton 6 Caswell No. 304 CCRIS 3501 Dilluorodi-chloromethane Electro-CF 12 EPA pesticide chemical code 000014 Eskimon 12 F 12 EC 12 Fluorocarbon 12 Freon 12 Freon F-12 Frigen 12 Genetron 12 Halon Halon 122 Isceon 122 Isotron 2 Kaiser chemicals 12 Ledon 12 Propellant 12 R 12 RCRA waste number U075 Refrigerant 12 Ucon 12 Ucon 12/halocarbon 12 UN 1028. 

Chlorofluorocarbons (CFCs) come in many forms, including those used as propellants for spray cans and for refrigeration (freon). They were banned as being potentially harmful to the ozone layer of the atmosphere. In 1987 an international agreement was signed by about 90 nations to reduce the use of CFCs by 50% by the year 2000. This did not seem adequate, so in 1990 a new treaty called for the elimination of the use of all CFCs by industrial nations. Some third world countries (e.g., China, India, Russia, and Mexico) still make and sell CFCs, some of which are smuggled into the United States. 

The chlorofluorocarbon compounds of methane and ethane are collectively known as freons. They are extremely stable, unreactlve, non-toxic, non-corrosive and easily liquefiable gases. Freon 12 (CCI2F2) Is one of the most common freons In Industrial use. It Is manufactured from tetrachloromethane by Swarts reaction. These are usually produced for aerosol propellants, refrigeration and air conditioning purposes. By 1974, total freon production In the world was about 2 billion pounds annually. Most freon, even that used In refrigeration, eventually makes Its way Into the atmosphere where It diffuses unchanged Into the stratosphere. In stratosphere, freon Is able to Initiate radical chain reactions that can upset the natural ozone balance (Unit 14, Class XI). 

Freon is a commercial trademark for a series of fluorocarbon products used in refrigeration and air-conditioning equipment, as aerosol propellants, blowing agents, fire extinguishing agents, and cleaning fluids and solvents. Many types contain chlorine as well as fluorine, and should be called chlorofluorocarbons (CFCs) [85,86]. 

FREON . Trademark of E.I. duPonc de Nemours Bt Co, Inc, Wilmington, Del fora line of fluorinated hydrocarbons used as propellants., refrigerants, blowing agents, fire extinguishers and solvents... 

Aerosol fogs as used in entomological work are of three general types an oil solution of the insecticide dispersed as microscopic droplets by a liquefied gas propellant, usually Freon a mist or fog produced by mechanical means a fog produced by means of a thermal aerosol fog generator. 

Freon-12 is used principally as a refrigerant, as a propellant for producing aerosol spray, and in some military applications which are classified... 

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