Metered-dose inhaler stringent set of criteria, they must: In the early days of MDIs the most commonly used propellants were the chlorofluorocarbons CFC-11, CFC-12 and CFC-114. In 2008 the Food and Drug Administration announced that inhalers using chlorofluorocarbons as a propellant, such as Primatene Mist, could no longer be manufactured or sold as of 2012. This followed from the U.S. decision to agree to the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. Phospholipids are important natural surfactant lipids used in enhancing penetration and bioavailability. Phospholipids act by reducing the high surface tension forces at the air-water interface within the
The Horse that Lost its Liberty (1484) under the title “Of the hors, of the hunter and of the hert” as teaching the moral given by Aristotle that "None ought to put hym self in subiection for to auenge hym on other". Samuel Croxall cites Horace’s conclusion that one should never yield one’s liberty to another for reasons of avarice. The fable was told as “The horse seeking vengeance on the stag ("Le cheval s'étant voulu venger du cerf") in La Fontaine's Fables and ends on the reflection that without personal liberty all other purchases are valueless: The alternative version of the fable concerns a boar