The primary objective is to compare the systemic exposure to tiotropium and CD 1857 after treatment with the fixed dose combination (fixed dose combination (FDC), Treatment A) of tiotropium plus BI 54903 (ethanolic solution for inhalation (EIS), Respimat (RMT) B) with the systemic exposure following inhalation of the free combination (Treatment B) of tiotropium (aqueous solution for inhalation (AIS), RMT A) plus BI 54903 (EIS, RMT B), when administered once-daily over 21 days via Respimat(R) (RMT).

The secondary objectives are:

to compare the systemic exposure to tiotropium and CD 1857 after single dose administration of FDC and of the free combination of tiotropium/BI 54903 to compare the systemic exposure to BI 54903 after a single dose and at steady state after multiple doses of the FDC and of the free combination of tiotropium/BI 54903 to compare the safety and tolerability of tiotropium and BI 54903 when administered as FDC and as free dose combination, respectively

Inclusion criteria:

1. Healthy males and females according to the following criteria: Based upon a complete medical history, including the physical examination, vital signs (blood pressure (BP), pulse rate (PR)), 12-lead electrocardiogram (ECG), clinical laboratory tests.
2. Age 21 to 50 years.

Exclusion criteria:

1. Any finding of the medical examination (including BP, PR and ECG) deviating from normal and of clinical relevance
2. Any evidence of a clinically relevant concomitant disease
3. Gastrointestinal, hepatic, renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders
4. History or evidence of relevant psychiatric disorders or neurological disorders
5. History or evidence of relevant autonomic dysfunction (orthostatic hypotension, fainting spells or blackouts)
6. Chronic or relevant acute infections
7. History of relevant allergy/hypersensitivity (including allergy to drug or its excipients)
8. Intake of any prescription drugs or over-the-counter (over the counter (OTC)) medication (vitamins, herbal supplements, dietary supplements) with a long half-life (> 24 hours) within at least one month or less than 10 half-lives of the respective drug prior to administration or during the trial
9. Participation in another trial with an investigational drug within two months prior to administration or during the trial
10. Smoker (more than 10 cigarettes daily)