Physical properties and clinical efficacy of two sodium cromoglycate inhalation aerosol preparations.

In this study, the particle size distribution and the droplet characteristics of the delivered aerosol cloud were first determined for two disodium cromoglycate inhalation aerosol preparations obtained from different manufacturers. In addition, the in vitro deposition properties and the clinical efficacy of these preparations were compared. The evaluation of the in vitro deposition was performed using a cascade impactor. The clinical efficacy was monitored by measuring the peak expiratory flow (PEF) values after the exercise test in fifteen asthmatic patients. The particle size and the spray characteristics of these two inhalation aerosol preparations were similar; the results of the in vitro test confirmed their similar physical properties. Both disodium cromoglycate preparations clearly alleviated the bronchoconstriction after the exercise test. According to the results of the clinical trial, supported by the laboratory scale studies, both disodium cromoglycate aerosols are of equal value in asthma inhalation therapy.