A Randomised, Open-Label, Single-Dose, Single-Centre, Crossover Study in Healthy Subjects to Assess the Relative Bioavailability of Symbicort pMDI 160/4.5µg Administered With a Spacer (With and Without Charcoal) and Symbicort pMDI 160/4.5µg Administered Without a Spacer (With and Without Charcoal)

This study will be conducted to establish the relative bioavailability of budesonide and formoterol delivered via Symbicort pressurized metered-dose inhaler (pMDI) with and without a spacer device.Administration under each condition will occur with the concomitant administration of activated charcoal to estimate exposure through the lung and without activated charcoal to estimate total systemic exposure.