GSK961081 is a potent dual pharmacophore that demonstrates both antimuscarinic and beta-agonist pharmacology in preclinical studies, both pharmacologies being of long duration. If reproduced in man, GSK961081 has the potential to deliver a medicine that can be given once daily. The bronchodilatation after inhalation of single doses of GSK961081 alone and in the presence of the short acting beta agonist salbutamol and the short acting muscarinic antagonist, ipratropium bromide will be measured in this study. Any residual bronchodilatation post-inhalation of GSK961081 and demonstrated by addition of salbutamol or ipratropium bromide may provide an indirect assessment of the beta-agonist and antimuscarinic components of GSK961081