Patients, devices and formulations

The success of inhalation therapy depends on exploiting the complex interaction between the patient, the inhalation device and the formulation it contains. For pressurised metered dose inhalers, good respirability demands stable particulate dispersions in approved propellents, valves which meter accurately and patients trained in suitable breathing manoeuvres. The comparable requirements for a powder inhaler are friable powder aggregates contained in a device capable of generating a turbulent aerodynamic regime at a low inspiratory resistance.