The demonstration of bronchodilator effects of salbutamol formulated in chlorofluorocarbon and hydrofluoroalkane-134a metered dose inhalation devices on leukotriene D4-Induced pulmonary responses in the guinea pig

ABSTRACT The demonstration of bronchodilator effects of β2-adrenergic agonists delivered by metered dose inhalation (MDI) devices can be useful in the development of new therapies for asthma or assessing the effects of a formulation. MDI formulations of hydrofluoroalkane (HFA)-134a (a chlorofluorocarbon [CFC]-free propellant), salbutamol in the HFA-134a propellant, CFC-P11/P12 propellant, and salbutamol and formoterol in the CFC propellant were evaluated for their ability to reduce leukotriene D4 (LTD4)-induced bronchoconstriction in guinea pigs using the Konzett-Rossler method. LTD4 challenges were made at various times up to 6 hours after MDI treatment. Neither the placebo vehicle propellants nor the drug formulations affected basal airflow. Only the salbutamol/CFC, formoterol/CFC, and salbutamol/HFA MDI formulations inhibited LTD4-induced bronchoconstriction. One actuation of the MDI device containing salbutamol or formoterol in the CFC propellant produced ∼100% inhibition of LTD4-induced effects follo...