Evaluation of Ciprofloxacin for Inhalation to Cystic Fibrosis Patients With P. Aeruginosa

Inclusion Criteria: * 6 to 17 years of age (inclusive) at Visit 1. * Positive sputum culture for P. aeruginosa * Clinical diagnosis of CF * FEV1 greater than or equal to 40% predicted normal lung function * Able to perform spirometry testing reproducibly according to ATS guidelines. Exclusion Criteria: * Use of an investigational agent within 30 days prior to Visit 1 (first dosing visit). * History of sputum culture or deep-throat cough swab (or BAL) culture yielding Burkholderia cepacia (B. cepacia), within 2 years prior to screening and/or sputum culture yielding B. cepacia at the Screening visit; * Use of any nebulized or systemic antibiotics within 14 days prior to Visit 1, other than maintenance oral macrolides that has been consistently used for at least 28 days prior to Visit 1. * History of intolerance or hypersensitivity to quinolone or fluoroquinolone class antibiotics * History of lung transplantation. * AST, ALT or total bilirubin \> 3 x upper limit of normal at screening. * History of hemoptysis \> 30 cc per episode during the 28 days prior to Visit 1. * Other present conditions, abnormality in screening laboratory tests or physical examination findings, that in the opinion of the Investigator or Medical Monitor would compromise the safety of the patient or the quality of the data.