Lung bioavailability of chlorofluorocarbon free, dry powder and chlorofluorocarbon containing formulations of 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 micrograms 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 (micrograms 30 min-1): CFC-free 42.4, CFC 43.8, DPI 45.3. Thus, the lung bioavailability of CFC-free was greater than that of CFC or DPI formulations of salbutamol.
Clark
D J
DJ
University Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee, UK.
Lipworth
B J
BJ
D000328:Adult; D000420:Albuterol / Q000493:pharmacokinetics*; D001682:Biological Availability; D017402:Chlorofluorocarbons / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male
D017402:Chlorofluorocarbons; D000420:Albuterol