• lung bioavailability;
  • chlorofluorocarbon;
  • metered-dose inhaler;
  • dry;
  • powder;
  • inhaler;
  • salbutamol.

With the future advent of a world wide ban on chlorofluorocarbon containing aerosols, a study was designed to compare the in vivo lung bioavailability of salbutamol via chlorofluorocarbon-containing metered-dose inhaler (CFC), chlorofluorocarbon-free metered-dose inhaler (CFC-free), and dry powder inhaler (DPI). Twelve healthy male subjects were given 1200 μg salbutamol and measurements made of plasma and urinary salbutamol. CFC-free produced significantly higher plasma salbutamol levels (ng ml-1; mean and 95% CI for difference) than either CFC or DPI: Cmax, CFC-free 4.18 vs CFC 3.29 (95% CI 0.10–1.68), vs DPI 3.42 (95% CI -0.03–1.56). The ratio for the difference in Cmax between CFC and CFC-free formulations was 1.32 (95% CI 1.02–1.61). There were no significant differences between CFC and DPI formulations. Urinary salbutamol results did not reveal any significant differences between the three inhalers (μg 30 min-1): CFC-free 42.4, CFC 43.8, DPI 45.3. Thus, the lung bioavailibility of CFC-free was greater than that of CFC or DPI formulations of salbutamol.