A Study of Tobramycin Inhalation Powder From a Modified Manufacturing Process Versus Placebo

Inclusion Criteria: * Written informed consent given by adults or by the parents/legal guardian in combination with the patient's assent, if capable of assenting, before any assessment was performed * Confirmed diagnosis of Cystic Fibrosis (CF) by the presence of one or more clinical features of CF in addition to: * a quantitative pilocarpine iontophoresis sweat chloride test of \>60 mEq/L; or * identification of well-characterized disease-causing mutations in each CFTR gene; or * an abnormal nasal transepithelial potential difference characteristic of CF. * Forced Expiratory Volume in one second (FEV1) at screening must have been ≥25% and ≤80% of normal predicted values for age, sex, and height based on Knudson criteria * P. aeruginosa must have been present in a sputum/deep-throat cough swab culture (or bronchoalveolar lavage \[BAL\]) within 6 months prior to screening and in the sputum/deep-throat cough swab culture at the screening visit * Able to expectorate a sputum sample or provide a deep throat cough swab at screening * Able to comply with all protocol requirements * Use of an effective means of contraception in females of childbearing potential * Clinically stable in the opinion of the investigator to be treated according to this protocol Exclusion Criteria: * FEV1 at baseline (Visit 2) \<25% or \>80% of normal predicted values for age, sex, and height based on Knudson criteria, and/or FEV1 at baseline (Visit 2) deviated by ≥10% from the FEV1 measured at screening (Visit 1) * Any use of inhaled anti-pseudomonal antibiotics within 4 months prior to screening * Any use of systemic anti-pseudomonal antibiotics within 28 days prior to study drug administration * Serum creatinine 2 mg/dL or above, blood urea nitrogen (BUN) 40 mg/dL or above, or an abnormal urinalysis defined as 2+ or greater proteinuria * Known local or systemic hypersensitivity to aminoglycosides or inhaled antibiotics * Signs and symptoms of acute pulmonary disease, e.g. pneumonia, pneumothorax * Administration of any investigational drug within 30 days prior to enrollment * Any previous exposure to tobramycin dry powder for inhalation (TIP) * Administration of loop diuretics within 7 days prior to study drug administration * Initiation of treatment with chronic macrolide therapy within 28 days prior to study drug administration * Initiation of treatment with dornase alfa within 28 days prior to study drug administration * Initiation of treatment with inhaled steroids (or increased dose) within 28 days prior to study drug administration * Initiation of treatment with inhaled hypertonic saline (HS) within 28 days prior to study drug administration * Personal history of abnormal hearing or family history of abnormal hearing other than typical hearing loss associated with the aging process * Known abnormal result from any audiology testing (defined as either a unilateral puretone audiometry test showing a threshold elevation \>20 dB at any frequency across the frequency range 0.25 kHz to 8 kHz or the absence of emission at the evoked otoacoustic emission test) * History of sputum culture or throat swab (or BAL) culture yielding Burkholderia cepacia (B. cepacia) within 2 years prior to screening and/or sputum culture yielding B. cepacia at screening * Hemoptysis of more than 60 mL at any time within 30 days prior to study drug administration * History of malignancy of any organ system (other than localized basal cell carcinoma of the skin), treated or untreated, within the past 5 years, regardless of evidence of local recurrence or metastases * Patients with clinically significant laboratory abnormalities (not associated with the study indication) at screening * Patients or caregivers with a history of noncompliance to medical regimens and patients or caregivers who are considered potentially unreliable * Pregnant or nursing (lactating) women * Women of child-bearing potential unless they used two reliable birth control methods Other protocol-defined inclusion/exclusion criteria may apply