The output of budesonide from nebulizers

Abstract

steroid therapy,1 no information is currently required by regulatory authorities on the dose of steroid actually reaching the patient from different nebulizers. As new, more efficient nebulizer designs are marketed, this information is essential to allow both therapeutic effects and side effects to be evaluated. We have studied the amount of a steroid suspension, budesonide, available for inhalation from a conventional jet nebulizer and from two newer designs. These “breath enhanced, open vent” nebulizers incorporate a system of valves to increase the gas flow through the nebulizer during inspiration, increasing drug delivery to the patient. Such nebulizers have been shown to double the delivery of a bronchodilator to the lung2 and have been suggested for use with nebulized steroids. We measured the output of budesonide from a conventional nebulizer, the Intersurgical Cirrus (Intersurgical Ltd, Wakingham, UK), which has a constant output throughout inspiration and expiration, and two breath-enhanced openvent nebulizers, the Medicaid Ventstream (Medicaid Ltd, Bognor Regis, UK) and the Pari LC Plus (Pari GmbH, Starnberg, Germany), which have enhanced output during inspiration only. In the laboratory part of our study, each nebulizer was charged with 2 mL (250 μg/mL) of budesonide suspension and operated for 5 minutes while attached to a sinus flow pump driven at different rates and volumes to represent breathing patterns of children. Budesonide was collected onto a filter and assayed with high-performance liquid chromatography. Each nebulizer type was tested 6 times. The particle size of budesonide released from each of the nebulizers was measured separately by using a glass multistage liquid impinger.3 In a parallel clinical study we measured the output of budesonide onto filters from different nebulizers when used by patients. Ten children with asthma aged 4 to 14 years used both the Ventstream and LC Plus nebulizers in random order for 5 minutes. The nebulizers contained 2 mL (500 μg) of budesonide nebulizer suspension, and drug that would have been inhaled was collected onto a The output of budesonide from nebulizers