- The bronchoprotective efficacy of salbutamol inhaled from a new metered-dose powder inhaler compared with a conventional pressurized metered-dose inhaler connected to a spacer. Seppälä, O.P., Herrala, J., Hedman, J., Alanko, K., Liipo, K., Terho, E., Pietinalho, A., Nyholm, J.E., Nieminen, M.M. Respiratory medicine. (1998)