Study to Evaluate the Safety and Pharmacokinetics of Inhaled Ciprofloxacin in Patients With Mild to Moderate Chronic Obstructive Pulmonary Disease (COPD)

Inclusion Criteria: * Adult patients with COPD (Stage I or II according to the GOLD Classification), 35 years of age or older * Airway obstruction with a post-bronchodilator Forced Expiratory Volume (FEV1) \> or equal 50% of predicted normal and a post-bronchodilator FEV1 / Forced Vital Capacity (FVC) \< 70%. * Current or ex-smokers with a smoking history of more than 10 pack-years * Body mass index (BMI) between 18 and 33 kg/m2 * Written informed consent to participate in the study after receiving adequate previous information and prior to any study specific procedures Exclusion Criteria: * Significant disease other than COPD as bronchial asthma, cystic fibrosis or clinically evident bronchiectasis * Total blood eosinophil count \>/=600/mm3. * Thoracotomy with pulmonary resection * Regular use of daytime oxygen therapy * Completion of a pulmonary rehabilitation program in the six weeks prior to the pre-study examination or current participation in a rehabilitation program * Hypersensitivity to the investigational drug or to other quinolones and/or to inactive constituents of the inhalation powder * Hypersensitivity of the bronchial system to inhalation of nebulized drugs or saline solution * Acute pulmonary exacerbation * Patients with a history of severe allergies, non-allergic drug reactions, or multiple drug allergies * Concomitant inhalative therapy with antibiotics and/or concomitant systemic therapy with fluoroquinolones * Oral beta-adrenergics, beta blockers * Long acting anti-cholinergics within 2 weeks prior to pre-study examination * Inhaled or oral steroids * Methylxanthines: 24-hour washout of short-acting theophylline and 48-hour washout of long-acting theophylline prior to pre-study examination * Antihistamines, antileukotrienes prescribed for asthma * oral cromolyn sodium or oral nedocromil sodium