Delivery of Nebulized Budesonide Liposomes to the Respiratory Tract of Allergic Sheep

ABSTRACT Inhaled budesonide has been shown to be an effective therapy for asthma. In a previous study in a sheep model, acute treatment with budesonide delivered by pressurized metered dose inhaler (pMDI) modified the late bronchoconstrictor response to inhaled antigen. In the present study, we utilized the same sheep model to assess whether the delivery of budesonide in a liposome preparation would modify the late asthmatic response and the associated airway hyperresponsiveness that is detectable 24 hours after challenge. In a crossover trial, six conscious intubated sheep were pretreated with 1 mg of budesonide/dilauroyl phosphatidylcholine (DLPC), or DLPC alone, 16 hours and again 1 hour prior to the administration of aerosolized Ascaris suum antigen. Using esophageal and tracheal pressure measurements and plethysmography, specific lung resistance (sRL) was measured over an 8-hour period following administration of the antigen. In addition, airway responsiveness to carbachol (as assessed by potential d...