Objectives of the study are to investigate the safety, tolerability and levels of ciprofloxacin in the lung after single and multiple inhalative administration to patients with moderate to severe COPD (stage II-III according to GOLD Criteria)

Inclusion Criteria:

• Adult patients with COPD, 40 to 75 years of age
• Diagnosis of COPD
• Airway obstruction with a post-bronchodilator Forced Expiratory Volume (FEV1) of >/=30% and </=65% of predicted and a post-bronchodilator FEV1 / Forced Vital Capacity (FVC) of </=70%
• Current or ex-smokers with a smoking history of more than 10 pack-years
• Patients must be able to produce acceptable induced sputum samples (as defined in the Study Procedure Manual)
• Normal body weight: Body Mass Index (BMI) between 19 and 35 kg/m2

Exclusion Criteria:

• Significant respiratory disease other than COPD as bronchial asthma, Cystic fibrosis or clinically evident bronchiectasis

• More than one COPD exacerbation within 12 months and within 8 weeks prior to screening

• total blood eosinophil count >/=600/mm3

• Thoracotomy with pulmonary resection

• Regularly use of daytime oxygen therapy for more than one hour per day and in the investigator's opinion will be unable to abstain from the use of oxygen therapy during clinic visits

• 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

• Patients with a history of severe allergies, non-allergic drug reactions, or multiple drug allergies

• Concomitant use of medication which could interfere with the investigational drug. Before study drug administration a wash out period of more than 5 half lives has to be considered

• Concomitant inhalative therapy with antibiotics and/or concomitant systemic therapy with

  • fluoroquinolones
  • Oral beta-andrenergics, beta blockers
  • 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