SINGLE DOSE COMPARISON BETWEEN A NOVEL MULTIPLE DOSE POWDER INHALER AND A CONVENTIONAL METERED DOSE INHALER IN ASTHMATIC-PATIENTS

Nineteen adult asthmatic patients participated in this trial to compare the clinical equivalence of a single dose of salbutamol inhaled either from a novel multiple dose powder inhaler* or a conventional metered dose inhaler. The trial was carried out as a randomized, double-blind, crossover study. The study consisted of two study days with a six-hour follow-up period of spirometric indices. In addition, blood pressure and heart rate were measured immediately before each lung function test. The mean maximum forced expiratory volume in one second (FEV1) after powder inhaler was 2.80 +/- 0.78 litres and after aerosol 2.90 +/- 0.76 litres. The mean areas under the curve (AUC) of absolute FEV1 values were 943 +/- 274 and 958 +/- 275 respectively. The mean percent change from the baseline in FEV1 was slightly greater after the aerosol than after the inhalation powder, but the difference was not statistically significant. Peak expiratory flow (PEF) and forced vital capacity (FVC) were similar after both preparations. The treatments tested had no effects on blood pressure or heart rate and both were well tolerated. In conclusion, the novel multiple dose powder inhaler showed clinical equivalence with the metered dose inhaler in delivering equal doses of salbutamol to asthmatic patients together with similar tolerability.