Pilot Pharmacokinetic Clenil Study With AeroChamber Plus™ or Volumatic™ Spacer Devices

Inclusion Criteria: * Male or non-pregnant female patients aged 18-65 years included. * Diagnosis of asthma according to GINA guidelines 2009 made at least 6 months prior to screening. * Patients already treated with a dose of BDP or equivalent up to 2000 µg/day. * FEV1 ≥ 60% of predicted for the patient's normal value at screening and randomisation Exclusion Criteria: * Patients treated with oral or parenteral corticosteroids in the previous 8 weeks (12 weeks for parenteral depot corticosteroids) before screening visit. * Exacerbation of asthma symptoms or hospitalization due to asthma exacerbation within the previous one month before screening until randomisation. * Lower respiratory tract infection within one month prior to screening. * Diagnosis of COPD as defined by the current GOLD 2009 (Global Initiative for Chronic Obstructive Lung Disease) Guidelines. * Significant medical history and/or treatments for cardiac, renal, neurological, hepatic, endocrine diseases, or any laboratory abnormality indicative of a significant underlying condition, that may interfere with patient's safety, compliance, or study evaluations, according to the Investigator's opinion. * Treatment with a xanthine derivative (e.g. theophylline) formulation in the 4 weeks prior to screening. * Any enzyme inducing or inhibiting drug (from 8 weeks before screening visit) * Patients who received any investigational new drug within the last 8 weeks before the screening. The patients cannot participate in another clinical study at the same time as the present study. * Blood donation (450 mL or more)or significant blood loss less than 12 weeks before the first intake of study drug.