Drug delivery systems.

Nebulizers, both jet and ultrasonic, were originally designed to convert a liquid solution into an aerosol. During recent years suspensions for nebulization have been developed and nebulized with the available devices. In-vitro comparisons of drug output from jet and ultrasonic nebulizers have shown significant differences between solutions and suspensions. Ex-vivo comparisons have confirmed the in-vitro results. In an ex-vivo trial with 10 adult healthy volunteers, budesonide suspension was compared with terbutaline solution in terms of inhaled mass of drug, when using either jet or ultrasonic dosimetric nebulizers (Spira). The inhaled mass of drug was defined as the dose of drug on a filter inserted between the nebulizer and the patient. The nebulizers were run to a fixed gravimetrically determined suspension output of 75% of the initial weight. The inhaled mass of drug as a percentage of the nominal dose was close to 50% for the terbutaline solution in both nebulizer systems, while the inhaled mass of drug as a percentage of the nominal dose for the budesonide suspension was about 30% for the jet nebulizer and about 10% for the ultrasonic nebulizer. However, the inhaled mass of drug measured in adults cannot be directly extrapolated to infants and children. In order to study the range of the inhaled mass of budesonide suspension in children an ex-vivo trial in 322 patients with bronchial asthma in the age range 0.6-15.7 years was performed.(ABSTRACT TRUNCATED AT 250 WORDS)